The cell wall composition and structure of the maize stalk directly affects its digestibility and in turn its feed value.Previous studies of stem quality have focused mostly on common maize germplasm,and few studies h...The cell wall composition and structure of the maize stalk directly affects its digestibility and in turn its feed value.Previous studies of stem quality have focused mostly on common maize germplasm,and few studies have focused on high-oil cultivars with high grain and straw quality.Investigation of the genetic basis of cell wall composition and digestibility of maize stalk using high-oil maize is desirable for improving maize forage quality.In the present study,a high-oil inbred line(By804)was crossed as male parent with the maize inbred line B73 to construct a population of 188 recombinant inbred lines(RILs).The phenotypes of six cell-wall-related traits were recorded,and QTL analysis was performed with a genetic map constructed with SNP markers.All traits were significantly correlated with one another and showed high broad-sense heritability.Of 20 QTLs mapped,the QTL associated with each trait explained 10.0%–41.1%of phenotypic variation.Approximately half of the QTL each explained over 10%of the phenotypic variation.These results provide a theoretical basis for improving maize forage quality by marker-assisted selection.展开更多
High and stable yield is the main goal of soybean genetic improvement.In this study,association analysis was used to detect the quantitative trait loci(QTL)for the plant height,and soybean growth period using 182 SSR ...High and stable yield is the main goal of soybean genetic improvement.In this study,association analysis was used to detect the quantitative trait loci(QTL)for the plant height,and soybean growth period using 182 SSR markers in the RIL population of 136 F_(4:8) lines,which developed from a cross between photoperiod-insensitive cultivar‘Dongnong 47’and photoperiod-sensitive variety PI317334–B.The results showed that 33 QTLs related to soybean growth period and plant height traits were detected by compound interval mapping,and were located on 12 linkage groups including N,C1,C2,J,D1a,B2,E,G,A2,O,L,I,with the contribution rate of 7.85–33.84%.These QTL loci and linkage markers related to soybean photoperiod sensitivity,would be helpful to identify key genes that control soybean photoperiod sensitivity,and provide an important basis for the breeding of new photoperiod-insensitive soybean varieties based on molecular design breeding.展开更多
Genetic diversity is one of the useful tools to select appropriate lines for hybridization. Twenty short</span><span style="font-family:Verdana;">-</span><span style="font-family:Ve...Genetic diversity is one of the useful tools to select appropriate lines for hybridization. Twenty short</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">statured</span><span style="font-family:""> </span><span style="font-family:Verdana;">maize inbred lines were taken for present study</span><span style="font-family:Verdana;">,</span><span style="font-family:""> </span><span style="font-family:Verdana;">which</span><span style="font-family:""><span style="font-family:Verdana;"> were collected from CIMMYT India and Mexico through Plant Breeding Division, Bangladesh Agricultural Research Institute (BARI), Gazipu</span><span style="font-family:Verdana;">r. This experiment was conducted </span></span><span style="font-family:Verdana;">from</span><span style="font-family:Verdana;"> November 2015 to April 2016 t</span><span style="font-family:Verdana;">o identify parental lines to produce single cross short statured</span><span style="font-family:""> </span><span style="font-family:Verdana;">maize hyb</span><span style="font-family:""><span style="font-family:Verdana;">rids. </span><span style="font-family:Verdana;">From th</span></span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> genetic diversity studies</span><span style="font-family:Verdana;">,</span><span style="font-family:""> </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">importance of both additive and non-additive</span><span style="font-family:Verdana;"> gene actions for the expression of yield and yield contributing characters were found. Values of vector I and II revealed that both the vectors had positive values for date of silking, plant height, rows/cob, grains/row and yield. These results indicated that these five characters had highest contribution towards divergence. Based on </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">relative magnitude of D</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> values;20 inbred lines were grouped into five clusters. Seven inbred lines were selected on the basis of genetic diversity and per se performance which will be crossed separately in a half</span></span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">diallel fashion to develop hybrids.展开更多
The objective of this article is to reveal the variations of ramie inbred lines in DNA level and discuss their molecular background to provide a theoretical basis for ramie cross breeding.In the present study,the gene...The objective of this article is to reveal the variations of ramie inbred lines in DNA level and discuss their molecular background to provide a theoretical basis for ramie cross breeding.In the present study,the genetic relationships among 33 inbred line accessions and two wild types that originated from China and Brazil were estimated using sequence-related amplified polymorphism(SRAP)markers.The results showed that 33 out of 81 primer combinations turned out to be polymorphic and 332 polymorphism bands were obtained.On the basis of the appearance of the markers,the genetic relationships were analyzed using unweighted pair-group method of arithmetic average cluster analysis(UPGMA),and the genetic Jaccard similarity coefficients were calculated.The inbred-lines originating from China and Brazil formed a cluster suggesting a possibility that the Brazilian cultivars could have developed from cultivars introduced from China. Within ramie inbred-lines,the groupings also indicated that the greatest genetic relationship among cultivars was correlated to the region of origin of cultivars.The results provided the evidence that SRAP was an efficient approach,suitable for taxonomic analysis of ramie inbred lines.To the authors'knowledge,this is the first application of SRAP marker on the systematics of ramie inbred lines.展开更多
Reproduction performance of 21 inbred experimental lines of White Leghorns was evaluated based on samples of reproduction records over a period of eight consecutive years. Two lines (63 and 72) have been extensively u...Reproduction performance of 21 inbred experimental lines of White Leghorns was evaluated based on samples of reproduction records over a period of eight consecutive years. Two lines (63 and 72) have been extensively used in studies, especially in research seeking for genetic and epigenetic factors underlying resistance to avian tumor virus-induced diseases in chickens. The other 19 lines are recombinant congenic strains (RCS), which were generated by crossing lines 63 and 72 followed by two consecutive backcrosses to the line 63 and then full-sib mating. In theory, each RCS processes 7/8 of progenitor background line 63 genome and a random sample (1/8) of the progenitor donor line 72 genome. All 21 inbred lines share a common major histocompatibility complex haplotype, B*2. The estimated average fertility of the 21 inbred lines ranged from 72.9% (RCS-J) up to 96.8% (RCS-P). Both progenitor lines 63 and 72 were observed with lower average fertility (82.4% and 81.6%, respectively) in comparison with the RCS except the RCS-J, suggesting a substantial polygenic component underlying the fertility phenotype. The average embryo mortality rate ranged from 14.5% (RCS-P) up to 47.0% (RCS-M). The background line 63 fell at about the middle of the range (28.3%) significantly higher than the donor line 72 (15.7%), which was among the group with the lowest embryo mortality. By definition, hatchability of fertile eggs is reversely correlated with embryo mortality. The average hatchability ranged from 26.5% (RCS-M) up to 66.8% (line 72) while the background line 63 remained (46.6%) at about the middle of the range. The variability of the average embryo mortality and hatchability observed among the 21 inbred lines indicated the two correlated traits also follow polygenic models of inheritance. Findings from this study paves the way for further investigation on genetic and environmental influence over reproductive performance of inbred lines of chickens, and particularly in understanding and improving the reproduction fitness of invaluable genetic resources like these inbred lines.展开更多
The amount of molecular marker information has considerable impact on the results of studies of crop germplasm genetic relationships in crop. The number of alleles required to reveal genetic relationship in maize inbr...The amount of molecular marker information has considerable impact on the results of studies of crop germplasm genetic relationships in crop. The number of alleles required to reveal genetic relationship in maize inbred lines is a theoretical issue that needs to be addressed. In this study, 112 pairs of SSR (simple sequence repeat) primers and 97 maize inbred lines were selected to study the relationship between the number of inbred lines and the number of SSR primers and alleles required for a stable cluster. The results showed that the number of SSR primers is not tightly associated with the stability of the cluster analysis results, while an increase in the number of alleles can significantly improve the stability of cluster analysis results. The number of inbred lines (X) is significantly associated with the number of alleles required for stable cluster analysis (Y), and the regression equation is Y= 600.8×e(-15.9/x). This equation can be used to calculate the number of SSR alleles required for a genetic relationship study of maize inbred lines. These results provide a reference for determining of SSR alleles number in genetic relationship analysis of maize inbred line and other crop germplasm.展开更多
Two important mycotoxins, aflatoxin and fumonisin, are among the most potent naturally occurring carcinogens, contaminating maize(Zea mays) and affecting crop yield and quality.Resistance of maize to pre-harvest mycot...Two important mycotoxins, aflatoxin and fumonisin, are among the most potent naturally occurring carcinogens, contaminating maize(Zea mays) and affecting crop yield and quality.Resistance of maize to pre-harvest mycotoxin contamination, specifically aflatoxin produced by Aspergillus flavus and fumonisin produced by Fusarium verticillioides, is a goal in breeding programs that screen for these important traits with the aim of developing resistant commercial hybrids. We conducted two years of field evaluations on 87 inbred lines originating primarily in China and Mexico and not previously screened for resistance.The objectives of our study were to identify resistant germplasm for breeding purposes and to examine possible relationships between resistances to the two mycotoxins. Aflatoxin and fumonisin were present in samples harvested from all lines in both years.Concentrations of total aflatoxin ranged from 52.00 ± 20.00 to 1524.00 ± 396.00 μg kg^(-1),while those of fumonisin ranged from 0.60 ± 0.06 to 124.00 ± 19.50 mg kg^(-1). The inbred lines TUN15, TUN61, TUN37, CY2, and TUN49 showed the lowest aflatoxin accumulation and CN1, GT601, TUN09, TUN61, and MP717 the lowest fumonisin accumulation. TUN61 showed the lowest accumulation of both mycotoxins. This study confirmed previous observations that high levels of aflatoxin can coexist with fumonisin, with 55 maize lines showing a positive correlation coefficient between the concentrations of aflatoxin and fumonisin and 32 lines showing a negative correlation coefficient. These selected lines,particularly TUN61, may provide sources of resistance to mycotoxin contamination in breeding programs. However, the mechanism of resistance in this germplasm remains to be identified. Future research should also address factors that influence the fungus–plant interaction, such as herbivory and environmental stress.展开更多
Strong seedlings are essential for high yield.To explore the foundation of strong seedlings,we investigated various factors influencing the conversion and distribution of seed storage reserves during seedling establis...Strong seedlings are essential for high yield.To explore the foundation of strong seedlings,we investigated various factors influencing the conversion and distribution of seed storage reserves during seedling establishment in maize inbred lines.Three maize inbred lines were used to explore the effects of seed size,seed vigor,illumination duration,temperature,water content,and salt concentration of the seedling medium on the utilization of seed storage reserves during seedling establishment.The results showed that the conversion rate of small seeds was 3.69 to 17.71%higher than that of large seeds.Moreover,prolonged illumination time was conducive to the formation of strong seedlings.However,low temperature,drought stress and salt stress reduced the conversion rate of seed storage reserves and increased the root/shoot ratio.These results could be used to guide field management during seedling emergence and develop improved germplasm with a high conversion rate of seed storage reserves.展开更多
[Objective] The primary objective of this study was to estimate combining ability and genetic parameters of 17 new inbred lines.[Method] By using 11 commonly used maize inbred lines from Southwest China as testers and...[Objective] The primary objective of this study was to estimate combining ability and genetic parameters of 17 new inbred lines.[Method] By using 11 commonly used maize inbred lines from Southwest China as testers and incomplete diallel cross design,combining ability and heterosis of 17 new inbred lines bred from the land races in Sichuan Basin and its surrounding areas were analyzed.In addition,the genetic parameters and heterotic groups were also investigated based on combining ability.[Result] P1-1,P1-16 and P1-14 with the better comprehensive characters can be directly used in maize breeding program.The SCA of P1-10×P2-4 was high in most traits.It is more possible to obtain high-yield hybrid combinations by the pattern Sipingtou × Lancaster.GCA variance was bigger than SCA variance in four traits such as rows per ear,grains per row,which were affected by the environments slightly and should be selected at early generations;while SCA variance was bigger than GCA variance in five traits such as 100-grain weight and plant weight,which were significantly influenced by environment and thus should be selected in later generations.[Conclusion] The paper will provide theoretical basis for further improvement of local maize varieties.展开更多
This paper used SSR molecular markers to perform the genetic diversity analysis on 13 ordinary inbred lines of maize of different sources in order to divide heterotic groups of maize inbred line and predict heterosis....This paper used SSR molecular markers to perform the genetic diversity analysis on 13 ordinary inbred lines of maize of different sources in order to divide heterotic groups of maize inbred line and predict heterosis. Using 12 pairs of SSR primers,a total of 47 allelic variants were detected in 13 inbred lines,2-5 alleles were detected for each pair of primers,an average of 3. 9,and polymorphism information content varied from 0. 379 to 0. 828. According to the cluster analysis,the 13 inbred lines could be divided into 5 groups.展开更多
The breeding technology of sunflower inbred lines with four generations in one year was explored through the research on the biological characteristics of sunflower itself and the breeding status of sunflower inbred l...The breeding technology of sunflower inbred lines with four generations in one year was explored through the research on the biological characteristics of sunflower itself and the breeding status of sunflower inbred lines using the young embryo culture technology,the greenhouse seedling technology and field test planting,based on sunflower field breeding and planting combined with greenhouse planting.The reasonable selection of planting sites as the core of the breeding technology of sunflower inbred lines with four generations in one year is a guarantee.Embryos can be taken 7-10 d after pollination to enter the next generation of cultivation,thus shortening the generational cultivation cycle.The establishment of a breeding method of sunflower inbred lines with four generations in one year reduces the cost of breeding and has a practical role and significance for the field of sunflower inbred line breeding technologies.展开更多
A major challenge facing those involved in the testing of new plant varieties for Distinctness, Uniformity and Stability (DUS) is the need to compare them against all those of 'common knowledge'. A set of maiz...A major challenge facing those involved in the testing of new plant varieties for Distinctness, Uniformity and Stability (DUS) is the need to compare them against all those of 'common knowledge'. A set of maize inbred lines was used to compare how morphological, physiological characterization and RAPD molecular marker described variety relationships. All the inbred lines were confirmed as morphologically and physiologically distinct. At morphological level the maximum genetic distance (10.8) and least genetic distance (1.6) were found. For physiological characters distance varied from 0.35 to 1.92 and results from dendrogram, which was made on the basis of dissimilarity matrix, were grouped into five major clusters. From RAPD, random primers provide polymorphic amplification products;the distance varying 0.42 to 0.65 and dendrogram showed that these lines formed close clusters due to the less variation in these lines at molecular level. In the present study, the molecular markers also exposed useful genetic diversity and the visual displays appeared to disperse the lines somewhat more evenly over the plot than the morphological and physiological methods.展开更多
On the basis of ascertaining the dominant and recessive relationship and separation ratio of quality traits such as leaf type and peel stripes,the separation of dominant and recessive traits was studied to infer wheth...On the basis of ascertaining the dominant and recessive relationship and separation ratio of quality traits such as leaf type and peel stripes,the separation of dominant and recessive traits was studied to infer whether the genes of the previous generation were homozygous.Individuals with homozygous recessive traits can be confirmed in F2 generation,and homozygous single lines with dominant traits can be confirmed in F3 generation,which speeds up the breeding process of watermelon inbred lines.展开更多
Plants which contain unisexual flowers are subjected to genetic degradation and yield capacity reduction due to the easily cross-pollination.Sponge gourd,one of species of the Cucurbitaceae which is predominantly cros...Plants which contain unisexual flowers are subjected to genetic degradation and yield capacity reduction due to the easily cross-pollination.Sponge gourd,one of species of the Cucurbitaceae which is predominantly cross-pollinating,is cultivated to widely use as vegetable in Vietnamese daily meals.The aim of this experiment was to evaluate the growth potential and fruit quality including fruit aroma of sponge gourd inbred lines.Pure line selection has been performed using self-pollinated method,so that sponge gourd lines would be recovered with high yielding and aroma and thereby recommended for further crop system in Thua Thien Hue province,Central Vietnam.The experiment was conducted in a randomized complete block design(RCBD)with three replications during the winter-spring season in 2017.Agronomical data were observed and analyzed on seven inbred lines(1-MN1,1-MN2,5-MN1,7-MN1,13-MN2,15-MN1 and 15-MN2)derived from B29 accession(GBVN006904).The results indicated that inbred lines 13-MN2,1-MN2 and 15-MN1 attained more highly fruit weight and yield compared to the others.Four inbred lines consisting of 5-MN1,7-MN1,15-MN1 and 15-MN2 still retained the light aroma after boiling.The inbred lines 1-MN2,7-MN1,13-MN2 and 15-MN1 are considered for appropriately using in breeding program of new luffa.展开更多
Several countries in Africa, Latin America along with China have incorporated QPM in their Agricultural development plan. A new quality protein maize variety (QPM) was developed by breeders and farmers using the parti...Several countries in Africa, Latin America along with China have incorporated QPM in their Agricultural development plan. A new quality protein maize variety (QPM) was developed by breeders and farmers using the participatory breeding approach in the DR-Congo. It is adapted to all the maize growing regions in the country. Inbred lines from this new variety were produced for further development of maize synthetic populations. The main objective of the present study is to determine the level of amino acid changes in early generations of inbred lines. The results of the study revealed a significant decrease of 33% and 38% of tryptophan in S1 and S2 inbred lines compared to the original parental MUDISHI 3 population, respectively. There was a decrease of 15% of lysine in S2 inbred lines compared to the parental MUDISHI 3. Actually, S2 inbred lines of MUDISHI 3 contain similar level of lysine compared to the genetically improved normal maize (Salongo 2) that is currently released. The development of composite lines is recommended over synthetic populations to maintain the high levels of lysine and tryptophan along with other desirable agronomic characteristics since they involve the intercrossing of open pollinated varieties.展开更多
Genetic stocks are considered to be mostimportant aspect in plant biological andmolecular studies.In the past,a fuzzless-lintless mutant(XZ142w)was introduced intoour group from Xuzhou Research Institute ofAgriculture...Genetic stocks are considered to be mostimportant aspect in plant biological andmolecular studies.In the past,a fuzzless-lintless mutant(XZ142w)was introduced intoour group from Xuzhou Research Institute ofAgriculture Sciences in China.A fuzzless-lintedmutant(GZNn)was found in our展开更多
Maize breeding efforts to generate high yielding and adaptive cultivars have recently been given emphasis by national maize breeding program. In Ethiopia, the maize production system is mainly dominated by subsistence...Maize breeding efforts to generate high yielding and adaptive cultivars have recently been given emphasis by national maize breeding program. In Ethiopia, the maize production system is mainly dominated by subsistence farmers where their production is below average. The objectives of this study were to determine the combining ability between lines and testers, and to evaluate the performance of crosses (hybrids) and parents for grain yield and yield component traits. Twenty-seven inbred lines were generated by crossing nine female lines (L1-L9) and three male testers (T1-T3) using line × tester mating system at International Maize and Wheat Improvement Center (CIMMYT), East African high land maize improvement program. The inbred lines along with parents were evaluated in randomized complete block design with two replications at three locations (Ambo, Kulumsa and Haramaya). Significant differences were observed among genotypes for all ten traits considered. Eight crosses (L1 × T2, L1 × T3, L3 × T3, L8 × T1, L4 × T2, L9 × T1, L2 × T1, and L2 × T2) had higher yield performance compared to other crosses across environments. Significant mean square differences were found across locations for general combining ability (GCA) due to lines for all traits except for number of kernel rows per ear, whereas GCA due to testers were significant only for grain yield, ear length and 1000-seed weight. Significant mean square due to GCA × Loc (both for lines and testers) was found for days to maturity (38.71*), 1000-seed weight (4582.36**) and grain yield (2756777**), while significant SCA × Loc interaction was found for all traits except number of kernel rows per ear (1.07), ear length (0.79) and ear diameter (0.12), suggesting that the importance of additive and non-additive gene effects in controlling these characters.展开更多
This study aimed to investigate chlorophyll content and photosynthetic characteristics of 17 pepper inbred lines which were selected independently. The results showed that chlorophyll contents significantly varied amo...This study aimed to investigate chlorophyll content and photosynthetic characteristics of 17 pepper inbred lines which were selected independently. The results showed that chlorophyll contents significantly varied among different inbred lines. To be specific,chlorophyll content of No. 68 inbred line was significantly higher than that of other 14 inbred lines; chlorophyll content of No. 55 inbred line was significantly lower than that of other 15 inbred lines. The chlorophyll content of various inbred lines showed a decreasing order of No. 68 > No. 47 > No. 66 > No. 62 > No. 63 > No. 60 > No. 61 > No. 64 > No. 56 > No. 67 > No. 65 > No. 48 > No. 59 > No. 58 > No. 57 > No. 69 > No. 55; the photosynthetic rate of various inbred lines showed a decreasing order of No. 68 > No. 57 > No. 60 > No. 48 > No. 58 > No. 47 > No. 62 > No. 63 > No. 64 > No. 65; the maximum photosynthetic rate of No. 65 inbred line was significantly lower than other seven inbred lines,while no significant difference was observed among other nine inbred lines.展开更多
基金supported by the National Key Research and Development Program of China(2017YFD0101201 and2016YFD0101002)the Chinese Academy of Agricultural Sciences through the Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2017-TRICAAS)National Engineering Laboratory for Crop Molecular Breeding
文摘The cell wall composition and structure of the maize stalk directly affects its digestibility and in turn its feed value.Previous studies of stem quality have focused mostly on common maize germplasm,and few studies have focused on high-oil cultivars with high grain and straw quality.Investigation of the genetic basis of cell wall composition and digestibility of maize stalk using high-oil maize is desirable for improving maize forage quality.In the present study,a high-oil inbred line(By804)was crossed as male parent with the maize inbred line B73 to construct a population of 188 recombinant inbred lines(RILs).The phenotypes of six cell-wall-related traits were recorded,and QTL analysis was performed with a genetic map constructed with SNP markers.All traits were significantly correlated with one another and showed high broad-sense heritability.Of 20 QTLs mapped,the QTL associated with each trait explained 10.0%–41.1%of phenotypic variation.Approximately half of the QTL each explained over 10%of the phenotypic variation.These results provide a theoretical basis for improving maize forage quality by marker-assisted selection.
基金This study was conducted in the Key Laboratory of Soybean Biology of Chinese Education Ministry,and financially supported by National Natural Science Foundation of China(32072086,31771820)Heilongjiang Province Natural Science Foundation(ZD2020C002).
文摘High and stable yield is the main goal of soybean genetic improvement.In this study,association analysis was used to detect the quantitative trait loci(QTL)for the plant height,and soybean growth period using 182 SSR markers in the RIL population of 136 F_(4:8) lines,which developed from a cross between photoperiod-insensitive cultivar‘Dongnong 47’and photoperiod-sensitive variety PI317334–B.The results showed that 33 QTLs related to soybean growth period and plant height traits were detected by compound interval mapping,and were located on 12 linkage groups including N,C1,C2,J,D1a,B2,E,G,A2,O,L,I,with the contribution rate of 7.85–33.84%.These QTL loci and linkage markers related to soybean photoperiod sensitivity,would be helpful to identify key genes that control soybean photoperiod sensitivity,and provide an important basis for the breeding of new photoperiod-insensitive soybean varieties based on molecular design breeding.
文摘Genetic diversity is one of the useful tools to select appropriate lines for hybridization. Twenty short</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">statured</span><span style="font-family:""> </span><span style="font-family:Verdana;">maize inbred lines were taken for present study</span><span style="font-family:Verdana;">,</span><span style="font-family:""> </span><span style="font-family:Verdana;">which</span><span style="font-family:""><span style="font-family:Verdana;"> were collected from CIMMYT India and Mexico through Plant Breeding Division, Bangladesh Agricultural Research Institute (BARI), Gazipu</span><span style="font-family:Verdana;">r. This experiment was conducted </span></span><span style="font-family:Verdana;">from</span><span style="font-family:Verdana;"> November 2015 to April 2016 t</span><span style="font-family:Verdana;">o identify parental lines to produce single cross short statured</span><span style="font-family:""> </span><span style="font-family:Verdana;">maize hyb</span><span style="font-family:""><span style="font-family:Verdana;">rids. </span><span style="font-family:Verdana;">From th</span></span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> genetic diversity studies</span><span style="font-family:Verdana;">,</span><span style="font-family:""> </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">importance of both additive and non-additive</span><span style="font-family:Verdana;"> gene actions for the expression of yield and yield contributing characters were found. Values of vector I and II revealed that both the vectors had positive values for date of silking, plant height, rows/cob, grains/row and yield. These results indicated that these five characters had highest contribution towards divergence. Based on </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">relative magnitude of D</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> values;20 inbred lines were grouped into five clusters. Seven inbred lines were selected on the basis of genetic diversity and per se performance which will be crossed separately in a half</span></span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">diallel fashion to develop hybrids.
基金the National High Technology Research and Development Program of China(2001AA241121)948 Project of the Ministry of Agriculture of China(2006-G18(03))the Key Technology R&D Program of Hubei Province,China(2007AA201C49)
文摘The objective of this article is to reveal the variations of ramie inbred lines in DNA level and discuss their molecular background to provide a theoretical basis for ramie cross breeding.In the present study,the genetic relationships among 33 inbred line accessions and two wild types that originated from China and Brazil were estimated using sequence-related amplified polymorphism(SRAP)markers.The results showed that 33 out of 81 primer combinations turned out to be polymorphic and 332 polymorphism bands were obtained.On the basis of the appearance of the markers,the genetic relationships were analyzed using unweighted pair-group method of arithmetic average cluster analysis(UPGMA),and the genetic Jaccard similarity coefficients were calculated.The inbred-lines originating from China and Brazil formed a cluster suggesting a possibility that the Brazilian cultivars could have developed from cultivars introduced from China. Within ramie inbred-lines,the groupings also indicated that the greatest genetic relationship among cultivars was correlated to the region of origin of cultivars.The results provided the evidence that SRAP was an efficient approach,suitable for taxonomic analysis of ramie inbred lines.To the authors'knowledge,this is the first application of SRAP marker on the systematics of ramie inbred lines.
文摘Reproduction performance of 21 inbred experimental lines of White Leghorns was evaluated based on samples of reproduction records over a period of eight consecutive years. Two lines (63 and 72) have been extensively used in studies, especially in research seeking for genetic and epigenetic factors underlying resistance to avian tumor virus-induced diseases in chickens. The other 19 lines are recombinant congenic strains (RCS), which were generated by crossing lines 63 and 72 followed by two consecutive backcrosses to the line 63 and then full-sib mating. In theory, each RCS processes 7/8 of progenitor background line 63 genome and a random sample (1/8) of the progenitor donor line 72 genome. All 21 inbred lines share a common major histocompatibility complex haplotype, B*2. The estimated average fertility of the 21 inbred lines ranged from 72.9% (RCS-J) up to 96.8% (RCS-P). Both progenitor lines 63 and 72 were observed with lower average fertility (82.4% and 81.6%, respectively) in comparison with the RCS except the RCS-J, suggesting a substantial polygenic component underlying the fertility phenotype. The average embryo mortality rate ranged from 14.5% (RCS-P) up to 47.0% (RCS-M). The background line 63 fell at about the middle of the range (28.3%) significantly higher than the donor line 72 (15.7%), which was among the group with the lowest embryo mortality. By definition, hatchability of fertile eggs is reversely correlated with embryo mortality. The average hatchability ranged from 26.5% (RCS-M) up to 66.8% (line 72) while the background line 63 remained (46.6%) at about the middle of the range. The variability of the average embryo mortality and hatchability observed among the 21 inbred lines indicated the two correlated traits also follow polygenic models of inheritance. Findings from this study paves the way for further investigation on genetic and environmental influence over reproductive performance of inbred lines of chickens, and particularly in understanding and improving the reproduction fitness of invaluable genetic resources like these inbred lines.
基金supported by the Natural Science Foundation of Shandong Province,China (Y2007D52)the Improved Variety Project of Shandong Province (2008 No.6)
文摘The amount of molecular marker information has considerable impact on the results of studies of crop germplasm genetic relationships in crop. The number of alleles required to reveal genetic relationship in maize inbred lines is a theoretical issue that needs to be addressed. In this study, 112 pairs of SSR (simple sequence repeat) primers and 97 maize inbred lines were selected to study the relationship between the number of inbred lines and the number of SSR primers and alleles required for a stable cluster. The results showed that the number of SSR primers is not tightly associated with the stability of the cluster analysis results, while an increase in the number of alleles can significantly improve the stability of cluster analysis results. The number of inbred lines (X) is significantly associated with the number of alleles required for stable cluster analysis (Y), and the regression equation is Y= 600.8×e(-15.9/x). This equation can be used to calculate the number of SSR alleles required for a genetic relationship study of maize inbred lines. These results provide a reference for determining of SSR alleles number in genetic relationship analysis of maize inbred line and other crop germplasm.
基金partially supported by the U.S.Department of Agriculture-Agricultural Research Service(USDA-ARS)the Georgia Agricultural Commodity Commission for Corn+1 种基金the National Corn Growers AssociationAMCOE(Aflatoxin Mitigation Center of Excellence)
文摘Two important mycotoxins, aflatoxin and fumonisin, are among the most potent naturally occurring carcinogens, contaminating maize(Zea mays) and affecting crop yield and quality.Resistance of maize to pre-harvest mycotoxin contamination, specifically aflatoxin produced by Aspergillus flavus and fumonisin produced by Fusarium verticillioides, is a goal in breeding programs that screen for these important traits with the aim of developing resistant commercial hybrids. We conducted two years of field evaluations on 87 inbred lines originating primarily in China and Mexico and not previously screened for resistance.The objectives of our study were to identify resistant germplasm for breeding purposes and to examine possible relationships between resistances to the two mycotoxins. Aflatoxin and fumonisin were present in samples harvested from all lines in both years.Concentrations of total aflatoxin ranged from 52.00 ± 20.00 to 1524.00 ± 396.00 μg kg^(-1),while those of fumonisin ranged from 0.60 ± 0.06 to 124.00 ± 19.50 mg kg^(-1). The inbred lines TUN15, TUN61, TUN37, CY2, and TUN49 showed the lowest aflatoxin accumulation and CN1, GT601, TUN09, TUN61, and MP717 the lowest fumonisin accumulation. TUN61 showed the lowest accumulation of both mycotoxins. This study confirmed previous observations that high levels of aflatoxin can coexist with fumonisin, with 55 maize lines showing a positive correlation coefficient between the concentrations of aflatoxin and fumonisin and 32 lines showing a negative correlation coefficient. These selected lines,particularly TUN61, may provide sources of resistance to mycotoxin contamination in breeding programs. However, the mechanism of resistance in this germplasm remains to be identified. Future research should also address factors that influence the fungus–plant interaction, such as herbivory and environmental stress.
基金supported by the National Key Research and Development Program of China(2018YFD0100900)the Special Fund of Agricultural Significant Application Technique Innovation of Shandong Province,China(SDAIT-02-02)the Maize Improved Seed Project in Shandong Province,China(2019LZGC002-1)。
文摘Strong seedlings are essential for high yield.To explore the foundation of strong seedlings,we investigated various factors influencing the conversion and distribution of seed storage reserves during seedling establishment in maize inbred lines.Three maize inbred lines were used to explore the effects of seed size,seed vigor,illumination duration,temperature,water content,and salt concentration of the seedling medium on the utilization of seed storage reserves during seedling establishment.The results showed that the conversion rate of small seeds was 3.69 to 17.71%higher than that of large seeds.Moreover,prolonged illumination time was conducive to the formation of strong seedlings.However,low temperature,drought stress and salt stress reduced the conversion rate of seed storage reserves and increased the root/shoot ratio.These results could be used to guide field management during seedling emergence and develop improved germplasm with a high conversion rate of seed storage reserves.
基金Supported by National Key Technology Research and DevelopmentProgram(2004BA525B04)Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education ofChina(IRT0453)Program for Maize breeding Key Technology ofSichuan Province during 11th Five-Year Plan Period
文摘[Objective] The primary objective of this study was to estimate combining ability and genetic parameters of 17 new inbred lines.[Method] By using 11 commonly used maize inbred lines from Southwest China as testers and incomplete diallel cross design,combining ability and heterosis of 17 new inbred lines bred from the land races in Sichuan Basin and its surrounding areas were analyzed.In addition,the genetic parameters and heterotic groups were also investigated based on combining ability.[Result] P1-1,P1-16 and P1-14 with the better comprehensive characters can be directly used in maize breeding program.The SCA of P1-10×P2-4 was high in most traits.It is more possible to obtain high-yield hybrid combinations by the pattern Sipingtou × Lancaster.GCA variance was bigger than SCA variance in four traits such as rows per ear,grains per row,which were affected by the environments slightly and should be selected at early generations;while SCA variance was bigger than GCA variance in five traits such as 100-grain weight and plant weight,which were significantly influenced by environment and thus should be selected in later generations.[Conclusion] The paper will provide theoretical basis for further improvement of local maize varieties.
文摘This paper used SSR molecular markers to perform the genetic diversity analysis on 13 ordinary inbred lines of maize of different sources in order to divide heterotic groups of maize inbred line and predict heterosis. Using 12 pairs of SSR primers,a total of 47 allelic variants were detected in 13 inbred lines,2-5 alleles were detected for each pair of primers,an average of 3. 9,and polymorphism information content varied from 0. 379 to 0. 828. According to the cluster analysis,the 13 inbred lines could be divided into 5 groups.
基金Supported by China Agriculture Research System of MOF and MARA(CARS-14-1-12)Science and Technology Research Project in Key Fields of the Corps(2021AB011)Science and Technology Project of the Nine Division(2021JS007).
文摘The breeding technology of sunflower inbred lines with four generations in one year was explored through the research on the biological characteristics of sunflower itself and the breeding status of sunflower inbred lines using the young embryo culture technology,the greenhouse seedling technology and field test planting,based on sunflower field breeding and planting combined with greenhouse planting.The reasonable selection of planting sites as the core of the breeding technology of sunflower inbred lines with four generations in one year is a guarantee.Embryos can be taken 7-10 d after pollination to enter the next generation of cultivation,thus shortening the generational cultivation cycle.The establishment of a breeding method of sunflower inbred lines with four generations in one year reduces the cost of breeding and has a practical role and significance for the field of sunflower inbred line breeding technologies.
文摘A major challenge facing those involved in the testing of new plant varieties for Distinctness, Uniformity and Stability (DUS) is the need to compare them against all those of 'common knowledge'. A set of maize inbred lines was used to compare how morphological, physiological characterization and RAPD molecular marker described variety relationships. All the inbred lines were confirmed as morphologically and physiologically distinct. At morphological level the maximum genetic distance (10.8) and least genetic distance (1.6) were found. For physiological characters distance varied from 0.35 to 1.92 and results from dendrogram, which was made on the basis of dissimilarity matrix, were grouped into five major clusters. From RAPD, random primers provide polymorphic amplification products;the distance varying 0.42 to 0.65 and dendrogram showed that these lines formed close clusters due to the less variation in these lines at molecular level. In the present study, the molecular markers also exposed useful genetic diversity and the visual displays appeared to disperse the lines somewhat more evenly over the plot than the morphological and physiological methods.
文摘On the basis of ascertaining the dominant and recessive relationship and separation ratio of quality traits such as leaf type and peel stripes,the separation of dominant and recessive traits was studied to infer whether the genes of the previous generation were homozygous.Individuals with homozygous recessive traits can be confirmed in F2 generation,and homozygous single lines with dominant traits can be confirmed in F3 generation,which speeds up the breeding process of watermelon inbred lines.
文摘Plants which contain unisexual flowers are subjected to genetic degradation and yield capacity reduction due to the easily cross-pollination.Sponge gourd,one of species of the Cucurbitaceae which is predominantly cross-pollinating,is cultivated to widely use as vegetable in Vietnamese daily meals.The aim of this experiment was to evaluate the growth potential and fruit quality including fruit aroma of sponge gourd inbred lines.Pure line selection has been performed using self-pollinated method,so that sponge gourd lines would be recovered with high yielding and aroma and thereby recommended for further crop system in Thua Thien Hue province,Central Vietnam.The experiment was conducted in a randomized complete block design(RCBD)with three replications during the winter-spring season in 2017.Agronomical data were observed and analyzed on seven inbred lines(1-MN1,1-MN2,5-MN1,7-MN1,13-MN2,15-MN1 and 15-MN2)derived from B29 accession(GBVN006904).The results indicated that inbred lines 13-MN2,1-MN2 and 15-MN1 attained more highly fruit weight and yield compared to the others.Four inbred lines consisting of 5-MN1,7-MN1,15-MN1 and 15-MN2 still retained the light aroma after boiling.The inbred lines 1-MN2,7-MN1,13-MN2 and 15-MN1 are considered for appropriately using in breeding program of new luffa.
文摘Several countries in Africa, Latin America along with China have incorporated QPM in their Agricultural development plan. A new quality protein maize variety (QPM) was developed by breeders and farmers using the participatory breeding approach in the DR-Congo. It is adapted to all the maize growing regions in the country. Inbred lines from this new variety were produced for further development of maize synthetic populations. The main objective of the present study is to determine the level of amino acid changes in early generations of inbred lines. The results of the study revealed a significant decrease of 33% and 38% of tryptophan in S1 and S2 inbred lines compared to the original parental MUDISHI 3 population, respectively. There was a decrease of 15% of lysine in S2 inbred lines compared to the parental MUDISHI 3. Actually, S2 inbred lines of MUDISHI 3 contain similar level of lysine compared to the genetically improved normal maize (Salongo 2) that is currently released. The development of composite lines is recommended over synthetic populations to maintain the high levels of lysine and tryptophan along with other desirable agronomic characteristics since they involve the intercrossing of open pollinated varieties.
文摘Genetic stocks are considered to be mostimportant aspect in plant biological andmolecular studies.In the past,a fuzzless-lintless mutant(XZ142w)was introduced intoour group from Xuzhou Research Institute ofAgriculture Sciences in China.A fuzzless-lintedmutant(GZNn)was found in our
文摘Maize breeding efforts to generate high yielding and adaptive cultivars have recently been given emphasis by national maize breeding program. In Ethiopia, the maize production system is mainly dominated by subsistence farmers where their production is below average. The objectives of this study were to determine the combining ability between lines and testers, and to evaluate the performance of crosses (hybrids) and parents for grain yield and yield component traits. Twenty-seven inbred lines were generated by crossing nine female lines (L1-L9) and three male testers (T1-T3) using line × tester mating system at International Maize and Wheat Improvement Center (CIMMYT), East African high land maize improvement program. The inbred lines along with parents were evaluated in randomized complete block design with two replications at three locations (Ambo, Kulumsa and Haramaya). Significant differences were observed among genotypes for all ten traits considered. Eight crosses (L1 × T2, L1 × T3, L3 × T3, L8 × T1, L4 × T2, L9 × T1, L2 × T1, and L2 × T2) had higher yield performance compared to other crosses across environments. Significant mean square differences were found across locations for general combining ability (GCA) due to lines for all traits except for number of kernel rows per ear, whereas GCA due to testers were significant only for grain yield, ear length and 1000-seed weight. Significant mean square due to GCA × Loc (both for lines and testers) was found for days to maturity (38.71*), 1000-seed weight (4582.36**) and grain yield (2756777**), while significant SCA × Loc interaction was found for all traits except number of kernel rows per ear (1.07), ear length (0.79) and ear diameter (0.12), suggesting that the importance of additive and non-additive gene effects in controlling these characters.
基金Supported by vegetable Station of Ningxia Hui Autonomous Region
文摘This study aimed to investigate chlorophyll content and photosynthetic characteristics of 17 pepper inbred lines which were selected independently. The results showed that chlorophyll contents significantly varied among different inbred lines. To be specific,chlorophyll content of No. 68 inbred line was significantly higher than that of other 14 inbred lines; chlorophyll content of No. 55 inbred line was significantly lower than that of other 15 inbred lines. The chlorophyll content of various inbred lines showed a decreasing order of No. 68 > No. 47 > No. 66 > No. 62 > No. 63 > No. 60 > No. 61 > No. 64 > No. 56 > No. 67 > No. 65 > No. 48 > No. 59 > No. 58 > No. 57 > No. 69 > No. 55; the photosynthetic rate of various inbred lines showed a decreasing order of No. 68 > No. 57 > No. 60 > No. 48 > No. 58 > No. 47 > No. 62 > No. 63 > No. 64 > No. 65; the maximum photosynthetic rate of No. 65 inbred line was significantly lower than other seven inbred lines,while no significant difference was observed among other nine inbred lines.
