[Objectives]This study was conducted to provide a reliable theoretical basis for the correct formulation of breeding programs for red-seed watermelon and the effective breeding of hybrid offspring.[Methods]With local ...[Objectives]This study was conducted to provide a reliable theoretical basis for the correct formulation of breeding programs for red-seed watermelon and the effective breeding of hybrid offspring.[Methods]With local varieties and inbred lines of red-seed watermelon as test materials,the generalized heritability of fruit number per plant,single-fruit weight,single-fruit seed number,single-fruit seed weight,seed kernel weight,1000-seed weight,kernel-producing ratio,seed production ratio and seed volume were estimated by variance analysis;and the heritability,genetic variation coefficients,and correlation of the nine yield traits in 43 red-seed watermelon varieties were studied.[Results]The generalized heritability of fruit number per plant,single-fruit weight,single-fruit seed number,single-fruit seed weight,seed kernel weight,1000-seed weight,kernel-producing ratio,seed production ratio and seed volume were 12.86%,80.14%,75.96%,74.39%,48.01%,17.12%,24.97%,18.60%,and 37.07%,respectively.The heritability of single-fruit weight,single-fruit seed number and single-fruit seed weight was higher,and early-generation individual selection could achieve a better effect on them;and 1000-seed weight and kernel-producing ratio had a higher coefficient of genetic variation,indicating a high selection potential.[Conclusions]Indirect selection could be achieved for traits such as the single-fruit seed number,single-fruit seed weight,seed kernel weight,and seed volume by selecting the single-fruit weight.In the process of red-seed watermelon breeding,traits with high heritability can be selected in early generations of hybrids,thus playing the role of early-generation orientation.展开更多
The study was conducted with the main objective to evaluate the genetic variability, heritability, and clustering pattern exploration of morphological and yield related traits in potato (Solanum tuberosum L.) collecti...The study was conducted with the main objective to evaluate the genetic variability, heritability, and clustering pattern exploration of morphological and yield related traits in potato (Solanum tuberosum L.) collections in the bimodal rainfall agroecological zone of Cameroon using a Randomized Complete Block Design (RCBD) with three replications. The data obtained on morphological and yield traits were subjected to analysis of variance (ANOVA). The results showed that the viability rate of the collections varied from 77.78% to 96.55% respectively for the Maffo and Desiree collections, while the greatest number of tubers per plant varied from 4 to 18 respectively for Synergie and Desiree. The emergence rate varies from 60% to 1.66% respectively for Maffo et Doza collections. However, Desiree presents the highest TL (96.55) while Maffo shows the lowest value (77.78%). The yield per hectare varied from 1.14 to 9.3 t/h for Maffo and Doza respectively. For all the characteristics observed, Phenotypic Coefficients of Variation (PCV) were higher than Genotypic Coefficients of Variation (GCV) suggesting the role of environment in the expression of traits under observation. The highest GCV and PCV 47.55 and 58.94 respectively were observed for Diameter at the collar (DC). Most of the traits showed high GAM (>20%)) except Average Tuber Length (ATL) with a moderate value (19.8). In terms of vegetative development, the Desiree variety showed the highest performance. Based on the growth and yield results, Doza seems to be the most recommendable crop in the study area.展开更多
Intraspecific trait variation and heritability in different environmental conditions not only suggest a potential for an evolutionary response but also have important ecological consequences at the population, communi...Intraspecific trait variation and heritability in different environmental conditions not only suggest a potential for an evolutionary response but also have important ecological consequences at the population, community, and ecosystem levels. However, the contribution of quantitative trait variation within a grassland species to evolutionary responses or ecological consequences is seldom documented. Leymus chinensis is an important dominant species in semi-arid grasslands of China, which has seriously suffered from drought and high temperature stresses in recent decades. In the present study, we measured variation and heritability of 10 quantitative traits, namely the number of tillers, maximum shoot height, number of rhizomes, maximum rhizome length, rhizome mass, aboveground mass, root mass, maximum net photosynthetic rate(Pmax), specific leaf area(SLA), and leaf length to leaf width ratio(LL/LW), for 10 genotypes of L. chinensis under one non-stress(Ck) condition and three environmental stress conditions(i.e., drought(Dr), high temperature(Ht), and both drought and high temperature(DrHt)). Result indicated that(1) the interaction of genotype and environmental condition(G×E) was significant for 6 traits but not significant for the other 4 traits as shown by two-way analysis of variance(ANOVA), suggesting that different selection forces were placed for different traits on the factors dominating phenotypic responses to different environmental conditions. Moreover, these significant G×E effects on traits indicated significantly different phenotypic adaptive responses among L. chinensis genotypes to different environmental conditions. Additionally, individuals could be grouped according to environmental condition rather than genotype as shown by canonical discriminant analysis, indicating that environmental condition played a more important role in affecting phenotypic variation than genotype;(2) by one-way ANOVA, significant differences among L. chinensis genotypes were found in all 10 traits under Ck and Dr conditions, in 8 traits under Dr Ht condition and only in 4 traits under Ht condition; and(3) all 10 traits showed relatively low or non-measurable broad-sense heritability(H_2) under stress conditions. However, the lowest H_2 value for most traits did not occur under DrHt condition, which supported the hypothesis of 'unfavorable conditions have unpredictable effects' rather than 'unfavorable conditions decrease heritability'. Results from our experiment might aid to improve predictions on the potential impacts of climate changes on L. chinensis and eventually species conservation and ecosystem restoration.展开更多
Ammonia,toxic to aquaculture organisms,represents a potential problem in aquaculture systems,and the situation is exacerbated in closed and intensive shrimp farming operations,expecially for Litopenaeus vannamei.Asses...Ammonia,toxic to aquaculture organisms,represents a potential problem in aquaculture systems,and the situation is exacerbated in closed and intensive shrimp farming operations,expecially for Litopenaeus vannamei.Assessing the potential for the genetic improvement of resistance to ammonia in L.vannamei requires knowledge of the genetic parameters of this trait.The heritability of resistance to ammonia was estimated using two descriptors in the present study:the survival time(ST) and the survival status at half lethal time(SS_(50)) for each individual under high ammonia challenge.The heritability of ST and SS_(50) were low(0.154 4±0.044 6 and 0.147 5±0.040 0,respectively),but they were both significantly different from zero(P<0.01).Moreover,these two estimates were basically the same and showed no significant differences from each other(P>0.05),suggesting that ST and SS_(50) could be used as suitable indicators for resistance to ammonia.There were also positive phenotypic and genetic correlation between resistance to ammonia and body weight,which means that resistance to ammonia can be enhanced by the improvement of husbandry practices that increase the body weight.The results from the present study suggest that the selection for higher body weight does not have any negative consequences for resistance to ammonia.In addition to quantitative genetics,tools from molecular genetics can be applied to selective breeding programs to improve the efficiency of selection for traits with low heritability.展开更多
Gene expression variation can be considered as a phenotype,and it plays an important role in both acclimation and adaption.However,genetic variation of gene expression received much less attention than traditional com...Gene expression variation can be considered as a phenotype,and it plays an important role in both acclimation and adaption.However,genetic variation of gene expression received much less attention than traditional commercial traits in aquaculture.To estimate the genetic variation and heritability of gene transcription in clam Meretrix petechialis,five Vibrio resistance-related genes were selected for gene expression analysis in the digestive gland,and an animal linear model was used to analyze data from quantitative real-time PCR(qRT-PCR).Among the five genes,BIRC7 showed significant additive genetic variations,the heritability of this gene of 12-month-and 15-month-old clams were 0.84±0.32 and 0.91±0.34,respectively.The heritability of other four genes(Bax,NFIL3,Big-Def,and CTL9)expression were low-tomoderate but not significantly expressed.Additionally,no significant phenotypic and genetic correlations between the BIRC7 transcription trait and body size were detected.This study highlights that certain gene expression variation is heritable and provides a reference for indirect selection of M.petechialis with high Vibrio resistance.展开更多
The investigation was carried out in focusing the genetic variability for different traits of wheat influenced by heat tolerance mechanism to find out relationships among phenological, physiological and yield contribu...The investigation was carried out in focusing the genetic variability for different traits of wheat influenced by heat tolerance mechanism to find out relationships among phenological, physiological and yield contributing traits. Spring wheat cultivar of 25 genotypes were selected and cultivated under late sowing condition at the Regional Wheat Research Institute, Shympur, Rajshahi, Bangladesh from December, 2016 to April, 2017. Significant variability among the genotypes exposed for different traits related to heat tolerance. Results showed that the genotypes G24, G10, G01, G13, G16, G25 and G14 </span><span style="font-family:Verdana;">ranked as better category considering maximum number of traits in mean</span><span style="font-family:Verdana;"> performance indicating their tolerance to heat stress under late sowing condition. Phenotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>) of all traits were greater than those of genotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>). The same trends were also found in their co-efficient of variances. The phenotypic co-efficient of variances (PCV) of all traits were greater compare to those of genotypic co-efficient of variances (GCV) and their values were closer to each other. The heading days (HD), canopy temperature at vegetative stage (CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">), canopy temperature at grain filling stage </span><span><span style="font-family:Verdana;">(CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">), biomass, plant height (PH), spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> (SPM), spikelet/spike (SPS), </span></span><span style="font-family:Verdana;">grain/</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">spike (GPS), thousand grain weight (TGW) and yield exhibited higher heritability (<i></span><span style="font-family:Verdana;">h<sub>b</sub><sup style="margin-left:-6px;">2</sup></span><span style="font-family:""><span style="font-family:Verdana;"></i>) estimated under irrigated late sowing (ILS) condition. Under the same ILS condition SPAD, SPM, SPS, GPS, TGW and yield showed moderate to high genetic advance (GA) obtained through computing their mean percentage (%) and the rest traits HD, maturity days (MD), CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">, CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">, biomass, PH and harvest index (HI) exposed smaller genetic advance (% mean). The co-efficient of variation (CV%) of all attributes in all genotypes were significantly lower (1.36</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">- 6.96). Both heritability and genetic advance were found lower for MD, SPAD and HI indicated their non additive genetic effects for </span><span style="font-family:Verdana;">which these traits might not be recommended for selection. However, </span><span style="font-family:Verdana;">spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">spikelet/spike, grain/spike, thousand grain weight and yield belonged to </span><span style="font-family:Verdana;">higher heritability and high to moderate genetic advance in mean percentage (%) along with wide genetic variation and lower environmental influence in heat stress situation indicated the most likely heritability due to the effects of additive genes that might be suggested as effective process of selection for these traits in heat stress condition.展开更多
Genetic improvement of crop plants is brought about by manipulating the genetic makeup through systematic breeding techniques or by employing modern biotechnological tools. Application of systematic breeding technique...Genetic improvement of crop plants is brought about by manipulating the genetic makeup through systematic breeding techniques or by employing modern biotechnological tools. Application of systematic breeding technique to a large extent is decided by the knowledge on the genetic control of the traits. Keeping this in view, nine mulberry genotypes were evaluated for different growth and yield attributing traits viz., number of tillers (NT), plant height (PH), total shoot length (TSL), nodal distance (ND), leaf fall % (LF), number of leaves/plant (NLP), weight of 100 fresh leaves (WFL), weight of 100 dry leaves (WDL), single leaf area (LA), leaf area index (LAI), aboveground biomass (AGB), leaf harvest index (LHI) and leaf yield (LY) and estimated the magnitude of genotypic and phenotypic variation, heritability, genetic advance and correlation coefficients. The broad sense heritability for these traits ranged from 63.942 (WFL) to 13.261 (PH). High heritability coupled with high genetic advance was recorded for the characters WFL, LF, LA, WDL and LY suggesting the higher genetic control over these traits. Leaf yield showed significantly positive phenotypic and genotypic correlations with all other growth traits except PH and LF. Leaf fall had significant negative correlations with all the highly heritable yield attributes viz., ND (-0.379), WDL (-0.225), LA (-0.346), LAI (-0.233) at 1% level and AGB (-0.148), LHI (-0.122) and LY (-0.146) at 5% level. Likewise, it showed positive correlations with TSL (0.558), NLP (0.264) and PH (0.221). Since mulberry is mainly cultivated for leaf yield, genotypes having higher WFL, LA, WDL and LY and less LF must be given importance during parent selection to evolve high yielding varieties with less leaf fall across different seasons in mulberry.展开更多
The experiment was conducted using simple lattice design with two replication and the trails was totally consisted fifty six genotypes.Data on seed yield and other Agronomic traits were used to estimate the genetic va...The experiment was conducted using simple lattice design with two replication and the trails was totally consisted fifty six genotypes.Data on seed yield and other Agronomic traits were used to estimate the genetic variability parameters,heritability and genetic advance(GA).Analysis of variance revealed highly significant and significant difference for all studied traits.Evaluated characters were exhibited different levels of variability,heritability and genetic advance among the studied genotypes.Low to high phenotypic coefficient of variation(PCV)and genotypic coefficient of variation(GCV)were recorded.The highest GCV and PVC values were found particularly for lodging percent(76.65%and 90.63%),harvest index(42.26%and 47.92%)yield per hectare(41.23%and 48.19%)and number of capsule per branch(30.81%and 37.25%)respectively,whereas low GCV and PCV(8.27%and 9.73%respectively)manifested for days to maturate.The highest broad sense heritability value manifested for harvest index(77.78%)followed by seed yield per hectare(73.21%),while lowest heritability(3.78%)revealed only for seed per capsule.In present study low to moderate genetic advance were manifested and high heritability and genetic advance as percentage of mean(>50)was recorded for lodging percentage,number of capsule per branch,seed yield per hectare and harvest index,indicating predominance of additive gene action for these characters.Therefore the result of this study suggests existence of variability for seed yield and other agronomic traits in these linseed genotypes,which should be exploited in future breeding.展开更多
Objective: To study the genetic and non-genetic factors and their interactions affecting growth rate and body weights at birth, weaning and at 6 months of age in Saudi Ardi, Damascus goats and their crosses. Methods: ...Objective: To study the genetic and non-genetic factors and their interactions affecting growth rate and body weights at birth, weaning and at 6 months of age in Saudi Ardi, Damascus goats and their crosses. Methods: Crossbreeding program between Saudi Ardi(A) goats with Damascus(D) was carried out to improve the meat productivity of Ardi goats through crossbreeding. The pedigree records of the body weights were obtained from 754 kids (397 males and 357 females) produced from 46 Sires and 279 Dams. Birth weight, weaning weigh and 6 months weight as well as average daily gain during different growth stages from birth to weaning (D1), weaning to 6 months (D2) and from birth to 6 months of age (D3) were recorded during winter/autumn and summer/spring. Data were classified according to breed, generation, sex, season, year, and type of birth. Data were analyzed using GLM procedure for the least-squares means of the fixed factors. Heritability and genetic parameters were estimated with derivative-free restricted maximum likelihood procedures using the MTDFREML program. Results: The percentages of variations were moderate for body weights and high for daily gains. Genetic groups had a highly significant (P<0.01) effect on the body weights traits. Damascus goats had higher (P<0.01) birth and weaning weights, but ?D?A group kids had a higher (P<0.01) body weight at 6 months. The genetic groups had a significant effects on the daily weight gains for D1 (P<0.01) and D3 (P<0.05) periods, whereas, it had no effects on D2 period. The fixed effects of sex, season, year and type of birth were significant differences for body weights. Male kids were heavier (P<0.01) than females for different growth stages. Body weights and daily gains during winter/autumn were significantly higher (P<0.01) than summer/spring. Kids born and raised as singles were significantly (P<0.01) heavier than those were born as twins or triplets. The genetic and phenotypic correlations between birth and weaning weights were positive for both Damascus and Ardi goats. Conclusions: Genetic program for Ardi goats through upgrading with Damascus is possible to improve meat production.展开更多
Ridgetail white prawn Exopalaemon carinicauda is an important economic marine species in China.To improve the germplasm quality of cultured E.carinicauda,for the fi rst time,we estimated the heritability of ammonia to...Ridgetail white prawn Exopalaemon carinicauda is an important economic marine species in China.To improve the germplasm quality of cultured E.carinicauda,for the fi rst time,we estimated the heritability of ammonia tolerance and survival of E.carinicauda,covering 263 full-sib families in multiple generations.Analysis models including binary linear animal model(BLA),binary linear sire-dam model(BLSD),probit threshold animal model(PTA),and probit threshold sire-dam model(PTSD)were used.The estimated heritability of tolerance to ammonia in diff erent models ranged from 0.09 to 0.22,and that of survival rate ranged from 0.06 to 0.16.Concerning the tolerance to ammonia,both the PTSD and BLSD models showed comparatively better prediction accuracies(0.48 and 0.47,respectively)than PTA and BLA models(0.40 and 0.26,respectively),while to the survival rate,all four models presented relatively low predictive abilities(0.16-0.26).This study provided important information for the future breeding program of E.carinicauda.展开更多
Growth traits of semi-sib families of Pinus elliottii were studied.The results showed that there were extremely significant differences between the P.elliottii families in terms of tree height,DBH and volume( P < 0...Growth traits of semi-sib families of Pinus elliottii were studied.The results showed that there were extremely significant differences between the P.elliottii families in terms of tree height,DBH and volume( P < 0.01),and the families could be selected effectively.Both family heritability and single plant heritability of growth traits of P.elliottii were high.The family heritability of tree height,DBH and volume was 0.799,0.779 and 0.770 respectively,and their single plant heritability was 0.683,0.829 and 0.742 respectively.Among them,the family heritability of tree height was the highest,while the single plant heritability of DBH was the highest.The Duncan analysis of growth traits of the P.elliottii families revealed that families 12,7,15,4 and 6 were superior families and can be used as high-yield families.展开更多
Background: It is well established that the people with elevated SBP, DBP, BMI and WHR are more prone to cardiovascular disease. However, very few studies have focused on the amount of familial aggregation and heritab...Background: It is well established that the people with elevated SBP, DBP, BMI and WHR are more prone to cardiovascular disease. However, very few studies have focused on the amount of familial aggregation and heritability of these cardiovascular risk factors in Indian population. Therefore, purpose of this study was to investigate the familial aggregation of blood pressures with respect to certain anthropometric traits and to determine the relative roles of heredity in the etiology of SBP and DBP in a sample of families with three generations. Methods: The study has been conducted through house to house family study among three generations such as offspring, parent and grandparent in a scheduled caste community (Ramdasia) in Punjab. A total of 1400 individuals, constituting 380 families were surveyed for blood pressure, pulse rate, pulse pressure and anthropometric measurements to study familial aggregation and heritability for cardiovascular risk factors. The analysis represents a multivariate model which includes the each individual family data for estimation of familial correlation and heritability. Results: All risk factors showed positive familial correlation but magnitudes are different in va rious pairs of combination. Correlations generally are higher among genetically close relatives such as brothersisters or parentoffspring and are lower among spouses. The estimated heri tabilities were 22% for systolic and 27% for diastolic blood pressure, 19% for BMI and 17% for WHR. Conclusions: These results indicate a strong familial aggregation of cardiovascular risk factors such as SBP and DBP in this population and also showed that this familial influence can be detected from anthropometric mea surements and genetic closeness. Almost all anthropometric variables were found to be significant with blood pressures among three ge nerations.展开更多
The exploitation of industrial strains of chickens in the Sahelian climate of Niger is characterized by a decline in performance and significant costs associated with their maintenance. In contrast, local chickens are...The exploitation of industrial strains of chickens in the Sahelian climate of Niger is characterized by a decline in performance and significant costs associated with their maintenance. In contrast, local chickens are well adapted to these environmental conditions but with poor production performance. Genetic selection of these local chickens could improve their productivity. The first step is to determine if the genetic parameters of their growth are high enough to ensure a successful selection strategy. To do so, weekly weights of 69 parents and 119 offspring were followed for 20 weeks. The heritability and genetic correlations of these weights were estimated through the Bayesian approach using the MCMCglmm package on R software. At hatching, weights ranged from 23 to 25 g. At 20 weeks, these weights ranged from 1031 to 1052 g for females and 1308 to 1445 g for males. Heritabilities for hatch weights at 4, 8, 12, 16, and 20 weeks of age were estimated to be 0.56, 0.31, 0.52, 0.53, 0.52 and 0.48 respectively and all genetic correlations were positive. In particular, weight at 8 weeks of age showed both good heritability (h<sup>2</sup> = 0.52) and strong, positive genetic correlations with weights at older ages. These results indicate that genetic selection to improve weight at 8 weeks of age would be a good strategy to improve the overall growth performance of these chickens.展开更多
To assess broad sense heritability and phenotypic and genetic correlations among sugarcane yield components, an experiment was conducted at Wonji and Metehara Sugar Estates of Sugar Corporation of Ethiopia during 2012...To assess broad sense heritability and phenotypic and genetic correlations among sugarcane yield components, an experiment was conducted at Wonji and Metehara Sugar Estates of Sugar Corporation of Ethiopia during 2012/2013. High broad sense heritability (h<sup>2</sup>) was detected for stalk diameter (0.730), single cane weight (0.672), millable cane number (0.624), stalk height (0.624) and pol % (0.608), indicating that these traits could be selected for easily. Expected genetic gain of the yield components was moderate to high. All traits had low to high genetic correlations (r<sub>g</sub> = -0.005 to 0.884) with cane yield and (r<sub>g</sub> = 0.027 to 0.999) with sugar yield. On average genetic correlations were higher than phenotypic correlations. High Genotypic Coefficient of Variation (GCV), broad sense heritability and expected genetic advance were recorded for stalk diameter, single cane weight and millable cane number. A selection strategy based on these traits could lead to improvement in cane and sugar yield.展开更多
Correlation and heritability studies of quantitative traits are a pre-requisite for judicious selection for genetic improvement of complex characters of economic importance. The success of selection is governed by the...Correlation and heritability studies of quantitative traits are a pre-requisite for judicious selection for genetic improvement of complex characters of economic importance. The success of selection is governed by the degree to which the desired trait is transmitted to the succeeding generation. The nature of selection is to be given due consideration at appropriate developmental stages for pursuing selection in desired direction while improving or evolving high productive breeds or hybrids of the silkworm. Characters showing high heritability as well as high genetic advance respond better to simple phenotypic selection while those having low heritability and low genetic advance may respond better to mass selection. Characters showing high heritability and low genetic advance may yield good response to hybridization and recurrent selection. An attempt has been made in this review article to briefly discuss the magnitude of correlation and heritability in selection strategies for the improvement of quantitative traits in desired direction in the silkworm, Bombyx mori (L.).展开更多
The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and cul...The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.展开更多
Oil palm germplasm collected from Angola,Africa in 1991 were subjected to genetic variability potential studies.The collection was planted in the form of open-pollinated families as trials at the Malaysian Palm Oil Bo...Oil palm germplasm collected from Angola,Africa in 1991 were subjected to genetic variability potential studies.The collection was planted in the form of open-pollinated families as trials at the Malaysian Palm Oil Board(MPOB)Kluang Research Station,Johor,Malaysia,in 1994.Dura palms from 52 families and tenera palms from 44 families of MPOB-Angola were evaluated for their bunch yield and bunch quality components.The objectives of this study were to determine the genetic variability among the families and performance of MPOB-Angola germplasm for yield improvement.The analysis of variance(ANOVA)revealed highly significant differences between the dura and tenera families for most of the traits,suggesting the presence of high genetic variability,which is essential for breeding programmes.Among the duras,family AGO 02.02 displayed the best yield performance,with a high fresh fruit bunch,oil yield and total economic product at 240.40,29.46 and 37.93 kg palm^(-1)year^(-1),respectively.As for the teneras,family AGO 03.04 recorded the highest FFB yield and oil yield at 249.25 and 45.22 kg palm^(-1)year^(-1),respectively.Besides that,several families with big fruit sizes or producing a mean fruit weight of 14-17 g were also identified.Both dura and tenera from AGO 01.01 recorded the highest oil to bunch(O/B)of 17.76%and 28.65%,respectively.These findings will facilitate the selection of palms from the MPOB-Angola germplasm for future breeding programmes.展开更多
Aims Genetic variation in plant traits represents the raw material for future adaptive evolution.Its extent can be estimated as heritability based on the performance of experimental plants of known relatedness,such as...Aims Genetic variation in plant traits represents the raw material for future adaptive evolution.Its extent can be estimated as heritability based on the performance of experimental plants of known relatedness,such as maternal half-sib seed families.While there is considerable heritability information for herbaceous plants and commercially important trees,little is known for woody species of natural subtropical forest.Moreover,it is open whether heritability is higher for species with r-or K-strategies,for more common species with larger distribution ranges than for rarer ones,or for populations closer to the centres of distributional ranges.Methods For 14 woody species in Chinese subtropical forest,we collected 13-38 maternal seed families,assessed seed size,grew replicates of each seed family in one more and one less benign nursery environment and measured stem diameter and plant height after 7 months.Important findings For the different species,plants grew 1.8-8.1 times taller in the more benign environment.For all 14 species,variation between seed families(and thus heritability)was significant(with very few exceptions at the P<0.001 level)for seed size and for stem diameter and plant height in both nurseries.Moreover,significant seed family by nursery interactions for stem diameter and plant height for all species(P<0.001)indicated significant heritability for plasticity in these traits.Multiple regression analysis suggests that heritabilities were higher for species with higher age at reproduction and higher wood density(traits indicating a K strategy)but also for species with higher specific leaf area(a trait rather indicating an r strategy).Furthermore,heritabilities were higher for species with larger range sizes,while there was no significant relationship between heritabilities and the distance of the study area to the range margins of our study species.In conclusion,the detected large heritability estimates suggest considerable potential for the evolution of plant performance and its plasticity for trees of subtropical forest.Moreover,our study shows that the simple method of comparing plants of different maternal seed families is valuable to address evolutionary ecological questions for so far understudied species.展开更多
Growth is an economically important trait in aquaculture.To improve growth trait of the Asian seabass(Lates calcarifer)we have been carrying out,since 2004,a selective breeding program.This study focuses on growth tra...Growth is an economically important trait in aquaculture.To improve growth trait of the Asian seabass(Lates calcarifer)we have been carrying out,since 2004,a selective breeding program.This study focuses on growth traits in the F2 fish generation,comprised of offspring from 23 mass crosses from 383 F_(1) brooders.Using genotyping analysis for 10 microsatellites from both brood stock and progeny we have reconstructed the pedigree of each mass-cross.For F_(2) generation at 90 days post hatch(dph),we have recorded body weight(BW)for 12,117 individuals and total length(TL),standard length(SL)and condition factor(K_(tl) and K_(sl))for 3530 individuals;and all five traits for 2136 individuals at 270 dph.At 90 dph the average BW was 46.88±20.95 g.Combining pedigree information,recorded growth traits and Restricted Maximum Likelihood method,we have estimated that the narrow sense heritability(h^(2))in F_(1) fish for BW,TL,SL,K_(tl) and K_(sl) was at,90 dph,0.12±0.03,0.11±0.03,0.10±0.03,0.20±0.04 and 0.11±0.03,respectively and,at 270 dph,0.34±0.07,0.32±0.07,0.30±0.06,0.13±0.04 and 0.11±0.04,respectively.At 90 dph the realised heritability for BW was 0.13.Comparing with F_(1) generation,the growth performance of F_(2) fish was increased by 14.4%.Heritability of growth traits will be useful for future genetic improvement programmes of the Asian seabass.展开更多
Two recent articles describe a pangenome of potato and a graph-based pangenome for tomato,respectively.The latter improves our understanding of the tomato genomics architecture even further and the use of this graph-b...Two recent articles describe a pangenome of potato and a graph-based pangenome for tomato,respectively.The latter improves our understanding of the tomato genomics architecture even further and the use of this graph-based pangenome versus a single reference dramatically improves heritability in tomato.展开更多
基金Supported by"Watermelon and Muskmelon Germplasm Innovation and Genetic Improvement"Post of Guangxi Bagui Scholars(2016A11)。
文摘[Objectives]This study was conducted to provide a reliable theoretical basis for the correct formulation of breeding programs for red-seed watermelon and the effective breeding of hybrid offspring.[Methods]With local varieties and inbred lines of red-seed watermelon as test materials,the generalized heritability of fruit number per plant,single-fruit weight,single-fruit seed number,single-fruit seed weight,seed kernel weight,1000-seed weight,kernel-producing ratio,seed production ratio and seed volume were estimated by variance analysis;and the heritability,genetic variation coefficients,and correlation of the nine yield traits in 43 red-seed watermelon varieties were studied.[Results]The generalized heritability of fruit number per plant,single-fruit weight,single-fruit seed number,single-fruit seed weight,seed kernel weight,1000-seed weight,kernel-producing ratio,seed production ratio and seed volume were 12.86%,80.14%,75.96%,74.39%,48.01%,17.12%,24.97%,18.60%,and 37.07%,respectively.The heritability of single-fruit weight,single-fruit seed number and single-fruit seed weight was higher,and early-generation individual selection could achieve a better effect on them;and 1000-seed weight and kernel-producing ratio had a higher coefficient of genetic variation,indicating a high selection potential.[Conclusions]Indirect selection could be achieved for traits such as the single-fruit seed number,single-fruit seed weight,seed kernel weight,and seed volume by selecting the single-fruit weight.In the process of red-seed watermelon breeding,traits with high heritability can be selected in early generations of hybrids,thus playing the role of early-generation orientation.
文摘The study was conducted with the main objective to evaluate the genetic variability, heritability, and clustering pattern exploration of morphological and yield related traits in potato (Solanum tuberosum L.) collections in the bimodal rainfall agroecological zone of Cameroon using a Randomized Complete Block Design (RCBD) with three replications. The data obtained on morphological and yield traits were subjected to analysis of variance (ANOVA). The results showed that the viability rate of the collections varied from 77.78% to 96.55% respectively for the Maffo and Desiree collections, while the greatest number of tubers per plant varied from 4 to 18 respectively for Synergie and Desiree. The emergence rate varies from 60% to 1.66% respectively for Maffo et Doza collections. However, Desiree presents the highest TL (96.55) while Maffo shows the lowest value (77.78%). The yield per hectare varied from 1.14 to 9.3 t/h for Maffo and Doza respectively. For all the characteristics observed, Phenotypic Coefficients of Variation (PCV) were higher than Genotypic Coefficients of Variation (GCV) suggesting the role of environment in the expression of traits under observation. The highest GCV and PCV 47.55 and 58.94 respectively were observed for Diameter at the collar (DC). Most of the traits showed high GAM (>20%)) except Average Tuber Length (ATL) with a moderate value (19.8). In terms of vegetative development, the Desiree variety showed the highest performance. Based on the growth and yield results, Doza seems to be the most recommendable crop in the study area.
基金funded by the National Key Research and Development Program of China (2016YFC0500706)the National Natural Science Foundation of China (31570427, 31770505)the China Scholarship Council (201606205032)
文摘Intraspecific trait variation and heritability in different environmental conditions not only suggest a potential for an evolutionary response but also have important ecological consequences at the population, community, and ecosystem levels. However, the contribution of quantitative trait variation within a grassland species to evolutionary responses or ecological consequences is seldom documented. Leymus chinensis is an important dominant species in semi-arid grasslands of China, which has seriously suffered from drought and high temperature stresses in recent decades. In the present study, we measured variation and heritability of 10 quantitative traits, namely the number of tillers, maximum shoot height, number of rhizomes, maximum rhizome length, rhizome mass, aboveground mass, root mass, maximum net photosynthetic rate(Pmax), specific leaf area(SLA), and leaf length to leaf width ratio(LL/LW), for 10 genotypes of L. chinensis under one non-stress(Ck) condition and three environmental stress conditions(i.e., drought(Dr), high temperature(Ht), and both drought and high temperature(DrHt)). Result indicated that(1) the interaction of genotype and environmental condition(G×E) was significant for 6 traits but not significant for the other 4 traits as shown by two-way analysis of variance(ANOVA), suggesting that different selection forces were placed for different traits on the factors dominating phenotypic responses to different environmental conditions. Moreover, these significant G×E effects on traits indicated significantly different phenotypic adaptive responses among L. chinensis genotypes to different environmental conditions. Additionally, individuals could be grouped according to environmental condition rather than genotype as shown by canonical discriminant analysis, indicating that environmental condition played a more important role in affecting phenotypic variation than genotype;(2) by one-way ANOVA, significant differences among L. chinensis genotypes were found in all 10 traits under Ck and Dr conditions, in 8 traits under Dr Ht condition and only in 4 traits under Ht condition; and(3) all 10 traits showed relatively low or non-measurable broad-sense heritability(H_2) under stress conditions. However, the lowest H_2 value for most traits did not occur under DrHt condition, which supported the hypothesis of 'unfavorable conditions have unpredictable effects' rather than 'unfavorable conditions decrease heritability'. Results from our experiment might aid to improve predictions on the potential impacts of climate changes on L. chinensis and eventually species conservation and ecosystem restoration.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A404)the Qingdao Postdoctoral Science Foundation Funded Project(No.Q51201403)+3 种基金the National Natural Science Foundation of China(Nos.31302179,31172402)the 948 Project from the Ministry of Agriculture of China(No.2015-Z17)the Improved Agricultural Breeds Engineering Project of Shandong Province-the Taishan Scholar Program for seed industry "Multi-Tarits Selective Breeding of New Variety and Its Industrialization"the Fundamental Research Funds for the Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences(No.20603022013011)
文摘Ammonia,toxic to aquaculture organisms,represents a potential problem in aquaculture systems,and the situation is exacerbated in closed and intensive shrimp farming operations,expecially for Litopenaeus vannamei.Assessing the potential for the genetic improvement of resistance to ammonia in L.vannamei requires knowledge of the genetic parameters of this trait.The heritability of resistance to ammonia was estimated using two descriptors in the present study:the survival time(ST) and the survival status at half lethal time(SS_(50)) for each individual under high ammonia challenge.The heritability of ST and SS_(50) were low(0.154 4±0.044 6 and 0.147 5±0.040 0,respectively),but they were both significantly different from zero(P<0.01).Moreover,these two estimates were basically the same and showed no significant differences from each other(P>0.05),suggesting that ST and SS_(50) could be used as suitable indicators for resistance to ammonia.There were also positive phenotypic and genetic correlation between resistance to ammonia and body weight,which means that resistance to ammonia can be enhanced by the improvement of husbandry practices that increase the body weight.The results from the present study suggest that the selection for higher body weight does not have any negative consequences for resistance to ammonia.In addition to quantitative genetics,tools from molecular genetics can be applied to selective breeding programs to improve the efficiency of selection for traits with low heritability.
基金Supported by the China Agriculture Research System(No.CARS-49)the National Natural Science Foundation of China(No.31772845)+1 种基金the Science and Technology Service Network Initiative of the Chinese Academy of Sciences(No.KFJ-STS-ZDTP-049)the Foundation of Zhejiang Key Laboratory of Exploitation and Preservation of Coastal Bio-Resource(No.J2018001)
文摘Gene expression variation can be considered as a phenotype,and it plays an important role in both acclimation and adaption.However,genetic variation of gene expression received much less attention than traditional commercial traits in aquaculture.To estimate the genetic variation and heritability of gene transcription in clam Meretrix petechialis,five Vibrio resistance-related genes were selected for gene expression analysis in the digestive gland,and an animal linear model was used to analyze data from quantitative real-time PCR(qRT-PCR).Among the five genes,BIRC7 showed significant additive genetic variations,the heritability of this gene of 12-month-and 15-month-old clams were 0.84±0.32 and 0.91±0.34,respectively.The heritability of other four genes(Bax,NFIL3,Big-Def,and CTL9)expression were low-tomoderate but not significantly expressed.Additionally,no significant phenotypic and genetic correlations between the BIRC7 transcription trait and body size were detected.This study highlights that certain gene expression variation is heritable and provides a reference for indirect selection of M.petechialis with high Vibrio resistance.
文摘The investigation was carried out in focusing the genetic variability for different traits of wheat influenced by heat tolerance mechanism to find out relationships among phenological, physiological and yield contributing traits. Spring wheat cultivar of 25 genotypes were selected and cultivated under late sowing condition at the Regional Wheat Research Institute, Shympur, Rajshahi, Bangladesh from December, 2016 to April, 2017. Significant variability among the genotypes exposed for different traits related to heat tolerance. Results showed that the genotypes G24, G10, G01, G13, G16, G25 and G14 </span><span style="font-family:Verdana;">ranked as better category considering maximum number of traits in mean</span><span style="font-family:Verdana;"> performance indicating their tolerance to heat stress under late sowing condition. Phenotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>) of all traits were greater than those of genotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>). The same trends were also found in their co-efficient of variances. The phenotypic co-efficient of variances (PCV) of all traits were greater compare to those of genotypic co-efficient of variances (GCV) and their values were closer to each other. The heading days (HD), canopy temperature at vegetative stage (CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">), canopy temperature at grain filling stage </span><span><span style="font-family:Verdana;">(CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">), biomass, plant height (PH), spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> (SPM), spikelet/spike (SPS), </span></span><span style="font-family:Verdana;">grain/</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">spike (GPS), thousand grain weight (TGW) and yield exhibited higher heritability (<i></span><span style="font-family:Verdana;">h<sub>b</sub><sup style="margin-left:-6px;">2</sup></span><span style="font-family:""><span style="font-family:Verdana;"></i>) estimated under irrigated late sowing (ILS) condition. Under the same ILS condition SPAD, SPM, SPS, GPS, TGW and yield showed moderate to high genetic advance (GA) obtained through computing their mean percentage (%) and the rest traits HD, maturity days (MD), CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">, CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">, biomass, PH and harvest index (HI) exposed smaller genetic advance (% mean). The co-efficient of variation (CV%) of all attributes in all genotypes were significantly lower (1.36</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">- 6.96). Both heritability and genetic advance were found lower for MD, SPAD and HI indicated their non additive genetic effects for </span><span style="font-family:Verdana;">which these traits might not be recommended for selection. However, </span><span style="font-family:Verdana;">spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">spikelet/spike, grain/spike, thousand grain weight and yield belonged to </span><span style="font-family:Verdana;">higher heritability and high to moderate genetic advance in mean percentage (%) along with wide genetic variation and lower environmental influence in heat stress situation indicated the most likely heritability due to the effects of additive genes that might be suggested as effective process of selection for these traits in heat stress condition.
文摘Genetic improvement of crop plants is brought about by manipulating the genetic makeup through systematic breeding techniques or by employing modern biotechnological tools. Application of systematic breeding technique to a large extent is decided by the knowledge on the genetic control of the traits. Keeping this in view, nine mulberry genotypes were evaluated for different growth and yield attributing traits viz., number of tillers (NT), plant height (PH), total shoot length (TSL), nodal distance (ND), leaf fall % (LF), number of leaves/plant (NLP), weight of 100 fresh leaves (WFL), weight of 100 dry leaves (WDL), single leaf area (LA), leaf area index (LAI), aboveground biomass (AGB), leaf harvest index (LHI) and leaf yield (LY) and estimated the magnitude of genotypic and phenotypic variation, heritability, genetic advance and correlation coefficients. The broad sense heritability for these traits ranged from 63.942 (WFL) to 13.261 (PH). High heritability coupled with high genetic advance was recorded for the characters WFL, LF, LA, WDL and LY suggesting the higher genetic control over these traits. Leaf yield showed significantly positive phenotypic and genotypic correlations with all other growth traits except PH and LF. Leaf fall had significant negative correlations with all the highly heritable yield attributes viz., ND (-0.379), WDL (-0.225), LA (-0.346), LAI (-0.233) at 1% level and AGB (-0.148), LHI (-0.122) and LY (-0.146) at 5% level. Likewise, it showed positive correlations with TSL (0.558), NLP (0.264) and PH (0.221). Since mulberry is mainly cultivated for leaf yield, genotypes having higher WFL, LA, WDL and LY and less LF must be given importance during parent selection to evolve high yielding varieties with less leaf fall across different seasons in mulberry.
文摘The experiment was conducted using simple lattice design with two replication and the trails was totally consisted fifty six genotypes.Data on seed yield and other Agronomic traits were used to estimate the genetic variability parameters,heritability and genetic advance(GA).Analysis of variance revealed highly significant and significant difference for all studied traits.Evaluated characters were exhibited different levels of variability,heritability and genetic advance among the studied genotypes.Low to high phenotypic coefficient of variation(PCV)and genotypic coefficient of variation(GCV)were recorded.The highest GCV and PVC values were found particularly for lodging percent(76.65%and 90.63%),harvest index(42.26%and 47.92%)yield per hectare(41.23%and 48.19%)and number of capsule per branch(30.81%and 37.25%)respectively,whereas low GCV and PCV(8.27%and 9.73%respectively)manifested for days to maturate.The highest broad sense heritability value manifested for harvest index(77.78%)followed by seed yield per hectare(73.21%),while lowest heritability(3.78%)revealed only for seed per capsule.In present study low to moderate genetic advance were manifested and high heritability and genetic advance as percentage of mean(>50)was recorded for lodging percentage,number of capsule per branch,seed yield per hectare and harvest index,indicating predominance of additive gene action for these characters.Therefore the result of this study suggests existence of variability for seed yield and other agronomic traits in these linseed genotypes,which should be exploited in future breeding.
文摘Objective: To study the genetic and non-genetic factors and their interactions affecting growth rate and body weights at birth, weaning and at 6 months of age in Saudi Ardi, Damascus goats and their crosses. Methods: Crossbreeding program between Saudi Ardi(A) goats with Damascus(D) was carried out to improve the meat productivity of Ardi goats through crossbreeding. The pedigree records of the body weights were obtained from 754 kids (397 males and 357 females) produced from 46 Sires and 279 Dams. Birth weight, weaning weigh and 6 months weight as well as average daily gain during different growth stages from birth to weaning (D1), weaning to 6 months (D2) and from birth to 6 months of age (D3) were recorded during winter/autumn and summer/spring. Data were classified according to breed, generation, sex, season, year, and type of birth. Data were analyzed using GLM procedure for the least-squares means of the fixed factors. Heritability and genetic parameters were estimated with derivative-free restricted maximum likelihood procedures using the MTDFREML program. Results: The percentages of variations were moderate for body weights and high for daily gains. Genetic groups had a highly significant (P<0.01) effect on the body weights traits. Damascus goats had higher (P<0.01) birth and weaning weights, but ?D?A group kids had a higher (P<0.01) body weight at 6 months. The genetic groups had a significant effects on the daily weight gains for D1 (P<0.01) and D3 (P<0.05) periods, whereas, it had no effects on D2 period. The fixed effects of sex, season, year and type of birth were significant differences for body weights. Male kids were heavier (P<0.01) than females for different growth stages. Body weights and daily gains during winter/autumn were significantly higher (P<0.01) than summer/spring. Kids born and raised as singles were significantly (P<0.01) heavier than those were born as twins or triplets. The genetic and phenotypic correlations between birth and weaning weights were positive for both Damascus and Ardi goats. Conclusions: Genetic program for Ardi goats through upgrading with Damascus is possible to improve meat production.
基金Supported by the National Key R&D Program of China(No.2018YFD0901302)the China Agriculture Research System-48(No.CARS-48)。
文摘Ridgetail white prawn Exopalaemon carinicauda is an important economic marine species in China.To improve the germplasm quality of cultured E.carinicauda,for the fi rst time,we estimated the heritability of ammonia tolerance and survival of E.carinicauda,covering 263 full-sib families in multiple generations.Analysis models including binary linear animal model(BLA),binary linear sire-dam model(BLSD),probit threshold animal model(PTA),and probit threshold sire-dam model(PTSD)were used.The estimated heritability of tolerance to ammonia in diff erent models ranged from 0.09 to 0.22,and that of survival rate ranged from 0.06 to 0.16.Concerning the tolerance to ammonia,both the PTSD and BLSD models showed comparatively better prediction accuracies(0.48 and 0.47,respectively)than PTA and BLA models(0.40 and 0.26,respectively),while to the survival rate,all four models presented relatively low predictive abilities(0.16-0.26).This study provided important information for the future breeding program of E.carinicauda.
基金Supported by National Key Research and Development Plan(2017YFD0600502)Forestry Science and Technology Planning Project of Hunan Province,China(XLK201307-2)
文摘Growth traits of semi-sib families of Pinus elliottii were studied.The results showed that there were extremely significant differences between the P.elliottii families in terms of tree height,DBH and volume( P < 0.01),and the families could be selected effectively.Both family heritability and single plant heritability of growth traits of P.elliottii were high.The family heritability of tree height,DBH and volume was 0.799,0.779 and 0.770 respectively,and their single plant heritability was 0.683,0.829 and 0.742 respectively.Among them,the family heritability of tree height was the highest,while the single plant heritability of DBH was the highest.The Duncan analysis of growth traits of the P.elliottii families revealed that families 12,7,15,4 and 6 were superior families and can be used as high-yield families.
文摘Background: It is well established that the people with elevated SBP, DBP, BMI and WHR are more prone to cardiovascular disease. However, very few studies have focused on the amount of familial aggregation and heritability of these cardiovascular risk factors in Indian population. Therefore, purpose of this study was to investigate the familial aggregation of blood pressures with respect to certain anthropometric traits and to determine the relative roles of heredity in the etiology of SBP and DBP in a sample of families with three generations. Methods: The study has been conducted through house to house family study among three generations such as offspring, parent and grandparent in a scheduled caste community (Ramdasia) in Punjab. A total of 1400 individuals, constituting 380 families were surveyed for blood pressure, pulse rate, pulse pressure and anthropometric measurements to study familial aggregation and heritability for cardiovascular risk factors. The analysis represents a multivariate model which includes the each individual family data for estimation of familial correlation and heritability. Results: All risk factors showed positive familial correlation but magnitudes are different in va rious pairs of combination. Correlations generally are higher among genetically close relatives such as brothersisters or parentoffspring and are lower among spouses. The estimated heri tabilities were 22% for systolic and 27% for diastolic blood pressure, 19% for BMI and 17% for WHR. Conclusions: These results indicate a strong familial aggregation of cardiovascular risk factors such as SBP and DBP in this population and also showed that this familial influence can be detected from anthropometric mea surements and genetic closeness. Almost all anthropometric variables were found to be significant with blood pressures among three ge nerations.
文摘The exploitation of industrial strains of chickens in the Sahelian climate of Niger is characterized by a decline in performance and significant costs associated with their maintenance. In contrast, local chickens are well adapted to these environmental conditions but with poor production performance. Genetic selection of these local chickens could improve their productivity. The first step is to determine if the genetic parameters of their growth are high enough to ensure a successful selection strategy. To do so, weekly weights of 69 parents and 119 offspring were followed for 20 weeks. The heritability and genetic correlations of these weights were estimated through the Bayesian approach using the MCMCglmm package on R software. At hatching, weights ranged from 23 to 25 g. At 20 weeks, these weights ranged from 1031 to 1052 g for females and 1308 to 1445 g for males. Heritabilities for hatch weights at 4, 8, 12, 16, and 20 weeks of age were estimated to be 0.56, 0.31, 0.52, 0.53, 0.52 and 0.48 respectively and all genetic correlations were positive. In particular, weight at 8 weeks of age showed both good heritability (h<sup>2</sup> = 0.52) and strong, positive genetic correlations with weights at older ages. These results indicate that genetic selection to improve weight at 8 weeks of age would be a good strategy to improve the overall growth performance of these chickens.
文摘To assess broad sense heritability and phenotypic and genetic correlations among sugarcane yield components, an experiment was conducted at Wonji and Metehara Sugar Estates of Sugar Corporation of Ethiopia during 2012/2013. High broad sense heritability (h<sup>2</sup>) was detected for stalk diameter (0.730), single cane weight (0.672), millable cane number (0.624), stalk height (0.624) and pol % (0.608), indicating that these traits could be selected for easily. Expected genetic gain of the yield components was moderate to high. All traits had low to high genetic correlations (r<sub>g</sub> = -0.005 to 0.884) with cane yield and (r<sub>g</sub> = 0.027 to 0.999) with sugar yield. On average genetic correlations were higher than phenotypic correlations. High Genotypic Coefficient of Variation (GCV), broad sense heritability and expected genetic advance were recorded for stalk diameter, single cane weight and millable cane number. A selection strategy based on these traits could lead to improvement in cane and sugar yield.
文摘Correlation and heritability studies of quantitative traits are a pre-requisite for judicious selection for genetic improvement of complex characters of economic importance. The success of selection is governed by the degree to which the desired trait is transmitted to the succeeding generation. The nature of selection is to be given due consideration at appropriate developmental stages for pursuing selection in desired direction while improving or evolving high productive breeds or hybrids of the silkworm. Characters showing high heritability as well as high genetic advance respond better to simple phenotypic selection while those having low heritability and low genetic advance may respond better to mass selection. Characters showing high heritability and low genetic advance may yield good response to hybridization and recurrent selection. An attempt has been made in this review article to briefly discuss the magnitude of correlation and heritability in selection strategies for the improvement of quantitative traits in desired direction in the silkworm, Bombyx mori (L.).
基金Supported by the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural(Aquaculture)Varieties(No.2021C02069-4-3)the Major Research&Development Program(Modern Agriculture)of Jiangsu Province(No.BE2019352)+1 种基金the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Innovation Project of Postgraduate Scientific Research in Huzhou University in 2022(No.2022KYCX63)。
文摘The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.
文摘Oil palm germplasm collected from Angola,Africa in 1991 were subjected to genetic variability potential studies.The collection was planted in the form of open-pollinated families as trials at the Malaysian Palm Oil Board(MPOB)Kluang Research Station,Johor,Malaysia,in 1994.Dura palms from 52 families and tenera palms from 44 families of MPOB-Angola were evaluated for their bunch yield and bunch quality components.The objectives of this study were to determine the genetic variability among the families and performance of MPOB-Angola germplasm for yield improvement.The analysis of variance(ANOVA)revealed highly significant differences between the dura and tenera families for most of the traits,suggesting the presence of high genetic variability,which is essential for breeding programmes.Among the duras,family AGO 02.02 displayed the best yield performance,with a high fresh fruit bunch,oil yield and total economic product at 240.40,29.46 and 37.93 kg palm^(-1)year^(-1),respectively.As for the teneras,family AGO 03.04 recorded the highest FFB yield and oil yield at 249.25 and 45.22 kg palm^(-1)year^(-1),respectively.Besides that,several families with big fruit sizes or producing a mean fruit weight of 14-17 g were also identified.Both dura and tenera from AGO 01.01 recorded the highest oil to bunch(O/B)of 17.76%and 28.65%,respectively.These findings will facilitate the selection of palms from the MPOB-Angola germplasm for future breeding programmes.
基金the consortium of BEF-China(www.bef-china.de)for the excellent intercultural and scientific team spiritthe German Science Foundation DFG for funding.
文摘Aims Genetic variation in plant traits represents the raw material for future adaptive evolution.Its extent can be estimated as heritability based on the performance of experimental plants of known relatedness,such as maternal half-sib seed families.While there is considerable heritability information for herbaceous plants and commercially important trees,little is known for woody species of natural subtropical forest.Moreover,it is open whether heritability is higher for species with r-or K-strategies,for more common species with larger distribution ranges than for rarer ones,or for populations closer to the centres of distributional ranges.Methods For 14 woody species in Chinese subtropical forest,we collected 13-38 maternal seed families,assessed seed size,grew replicates of each seed family in one more and one less benign nursery environment and measured stem diameter and plant height after 7 months.Important findings For the different species,plants grew 1.8-8.1 times taller in the more benign environment.For all 14 species,variation between seed families(and thus heritability)was significant(with very few exceptions at the P<0.001 level)for seed size and for stem diameter and plant height in both nurseries.Moreover,significant seed family by nursery interactions for stem diameter and plant height for all species(P<0.001)indicated significant heritability for plasticity in these traits.Multiple regression analysis suggests that heritabilities were higher for species with higher age at reproduction and higher wood density(traits indicating a K strategy)but also for species with higher specific leaf area(a trait rather indicating an r strategy).Furthermore,heritabilities were higher for species with larger range sizes,while there was no significant relationship between heritabilities and the distance of the study area to the range margins of our study species.In conclusion,the detected large heritability estimates suggest considerable potential for the evolution of plant performance and its plasticity for trees of subtropical forest.Moreover,our study shows that the simple method of comparing plants of different maternal seed families is valuable to address evolutionary ecological questions for so far understudied species.
基金This study was supported by the project“Selective Breeding of Marine Food Fish”funded by AVA,Singapore and by the Singapore National Research Foundation under CRP Award No.NRF-CRP7-2010-01.
文摘Growth is an economically important trait in aquaculture.To improve growth trait of the Asian seabass(Lates calcarifer)we have been carrying out,since 2004,a selective breeding program.This study focuses on growth traits in the F2 fish generation,comprised of offspring from 23 mass crosses from 383 F_(1) brooders.Using genotyping analysis for 10 microsatellites from both brood stock and progeny we have reconstructed the pedigree of each mass-cross.For F_(2) generation at 90 days post hatch(dph),we have recorded body weight(BW)for 12,117 individuals and total length(TL),standard length(SL)and condition factor(K_(tl) and K_(sl))for 3530 individuals;and all five traits for 2136 individuals at 270 dph.At 90 dph the average BW was 46.88±20.95 g.Combining pedigree information,recorded growth traits and Restricted Maximum Likelihood method,we have estimated that the narrow sense heritability(h^(2))in F_(1) fish for BW,TL,SL,K_(tl) and K_(sl) was at,90 dph,0.12±0.03,0.11±0.03,0.10±0.03,0.20±0.04 and 0.11±0.03,respectively and,at 270 dph,0.34±0.07,0.32±0.07,0.30±0.06,0.13±0.04 and 0.11±0.04,respectively.At 90 dph the realised heritability for BW was 0.13.Comparing with F_(1) generation,the growth performance of F_(2) fish was increased by 14.4%.Heritability of growth traits will be useful for future genetic improvement programmes of the Asian seabass.
文摘Two recent articles describe a pangenome of potato and a graph-based pangenome for tomato,respectively.The latter improves our understanding of the tomato genomics architecture even further and the use of this graph-based pangenome versus a single reference dramatically improves heritability in tomato.
