Grain appearance quality traits,measured as grain length(GL),grain width(GW),length to width ratio(LWR),grain thickness(GT) and the percentage of grain with chalkiness(PGWC),as well as 1 000-grain weight(TGW),are very...Grain appearance quality traits,measured as grain length(GL),grain width(GW),length to width ratio(LWR),grain thickness(GT) and the percentage of grain with chalkiness(PGWC),as well as 1 000-grain weight(TGW),are very important factors that contribute to rice grain quality and yield.To detect quantitative trait loci(QTLs) affecting these traits,we developed a set of recombinant inbred lines(RILs) derived from Gang46B(G46B) and K1075,a G46 B introgression line with lower PGWC.Based on a linkage map containing 33 simple sequence repeat(SSR) markers,a total of 15 additive QTLs governing six measured traits were identified on 4 chromosomes across two environments.Of these,the five major QTLs which controlled GW,LWR,GT,PGWC,and TGW,each explaining up to 44.30,55.29,62.30,30.94,and 28.78%of the variation,respectively,were found in the same interval of RM18004-RM18068 on chromosome 5.The G46 B alleles contributed to the increase in GW,GT and PGWC at all loci,as well as the increase in TGW at its major QTL locus.Significant interactions between additive QTL and the environment were found at most loci,in which the largest,accounting for15.06%of variation,was observed between qPGWC-5 and the environment.A total of 15 epistasis QTLs were detected for all the traits,and GL,GW and PGWC had significant epistasis QTLs based on environment interactions with minor effects.These results are valuable for future map-based cloning of the QTLs and the collaborative improvement of G46 B in grain appearance quality and yield.展开更多
Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristi...Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristics of agronomic performance when comparing inter-sub-specific hybrid rice(IHR) and inbred japonica rice(IJR) under mechanical transplanting method. In 2013 and 2014, field experiments were conducted using IHR(Yongyou 2640) and IJR(Wuyunjing 24) under two cultivation patterns, that is, pot seedlings mechanically transplanted(PS) and carpet seedlings mechanically transplanted(CS). Grain yield, yield components, leaf area index(LAI), leaf area duration(LAD), aboveground biomass, crop growth rate(CGR), nitrogen(N) uptake, and N accumulation were investigated. When compared with CS, PS displayed significantly increased grain yield for both varieties because the larger sink size allowed higher N accumulation from panicle initiation to maturity. Moreover, total aboveground biomass under PS increased significantly compared with that under CS; that is, higher photosynthetic productivity resulted from a greater LAI and higher LAD during the grain filling stage. Higher N absorption capacity in the middle and late growth periods resulted in significantly enhanced total N uptake under PS. When compared with IJR for both treatments, IHR generated 75.2% more grain yield. However, the characteristics creating high yield of IHR were different from those of IJR. Greater aboveground biomass production as well as higher N uptake and accumulation created higher grain yield in IHR than in IJR. These results suggest higher yield could be achieved using PS with IHR, attributing to exploit both yield superiority and productive potential.展开更多
Here, we analyzed whether the microRNA (miRNA) expression levels differ between maize inbred lines B73 and Mo17 and their reciprocal hybrids under salt and drought stress. We found that miR156, miR164, miR166, miR168,...Here, we analyzed whether the microRNA (miRNA) expression levels differ between maize inbred lines B73 and Mo17 and their reciprocal hybrids under salt and drought stress. We found that miR156, miR164, miR166, miR168, miR171 and miR319 are differentially expressed under abiotic stress. Interestingly, Mo17 × B73 showed the strongest change in miRNA expression in response to salt or drought stress, and was also the most resilient line when under abiotic stress in terms of water loss. In summary, our findings open the possibility that differential miRNA expression levels might be involved in heightened stress tolerance in maize hybrids.展开更多
Lancaster Surecrop (LSC) germplasm in inbreds of the Lancaster heterotic group in China was mainly provided by the two inbreds Mo17 and Oh43. Furthermore, the source of LSC germplasm was severely restricted in two inb...Lancaster Surecrop (LSC) germplasm in inbreds of the Lancaster heterotic group in China was mainly provided by the two inbreds Mo17 and Oh43. Furthermore, the source of LSC germplasm was severely restricted in two inbreds, C103 and Oh40B. The contents of LSC germplasm are 50% or less in inbreds of the group, with the existence of more than 20 non-LSC germplasms that results in the abundant genetic diversity in the group. Most inbreds of Mo17 subgroup contain 25 % - 50 % LSC, 12.5 % - 25 % Reid Yellow Dent (RYD)and 12.5% - 25% Iowa Goldmine germplasms in the ratio of 2:1:1, and most inbreds of Zi330 subgroup contain 12.5%-25% LSC, 6.25%- 12.5% RYD, 6.25%- 12.5% Minnesota # 13 and 25%- 50% Creole germplasms in the ratio of 2:1:1: 4. All the facts indicated that the germplasm base of the Lancaster heterotic group has stupendously changed and evolved away from actual LSC germplasm.展开更多
Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining abil...Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining ability and genetic relationship of 25 inbreds extracted from five tropical maize populations and a land race, with four temperate maize inbreds (Huangzaosi, Mo17, B73 and Dan 340). The 25 tropical inbreds were crossed with the four temperate inbreds and evaluated. Lines from Suwan1 and POP28 had high general combining ability (GCA) for grain yield. The lines from POP32 (ETO) had the highest special combining ability (SCA) with B73; the average SCA value of the 5 lines was 879 kg/ha. The lines from Suwan1had the second-highest SCA (584 kg/ha) with Huangzaosi. The lines from Suwan1 had the greatest relative heterosis (20%) with B73, followed by the lines from POP32 (ETO) with B73 (19%). Five heterotic patterns have been identified from this study: Suwan1 × Reid, ETO × Reid, POP28 × Reid, POP28 × Ludahonggu, and Suwan1 × Lancaster.展开更多
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
To identify stable quantitative trait loci(QTLs)responsible for sheath blight resistance,a recombinant inbred line mapping population consisting of 219 lines was developed by crossing Lemont and Yangdao 4.Average dise...To identify stable quantitative trait loci(QTLs)responsible for sheath blight resistance,a recombinant inbred line mapping population consisting of 219 lines was developed by crossing Lemont and Yangdao 4.Average disease rating,average lesion length,maximum disease rating and maximum lesion length were assayed in six different environments.A total of 128 minor effect QTLs were detected by multiple interval mapping.These QTLs explained less than 11.2%of the phenotypic variations individually,and 106 QTLs were clustered in 20 QTL-rich regions/putative loci.Significant QTL×environment interactions were detected at three putative loci(qSBR11.1,qSBR11.2 and qSBR11.3),indicating that these three loci were not stable.The other 17 stable loci(qSBR1.1,qSBR1.2,qSBR2.1,qSBR2.3,qSBR3.1,qSBR3.2,qSBR3.5,qSBR3.6,qSBR5.1,qSBR7.1,qSBR8.1,qSBR9.1,qSBR9.2,qSBR9.3,qSBR12.1,qSBR12.2 and qSBR12.4)provided a foundation for marker-assisted selection in breeding.Analysis of allelic effect on the 20 putative loci identified 7 highly stable loci,including qSBR3.2,qSBR7.1,qSBR8.1,qSBR9.2,qSBR9.3,qSBR12.1 and qSBR12.2.展开更多
An elite backcrossed inbred line Z550 with increased grains per panicle was identified from advanced backcrosses between Nipponbare and Xihui 18 by simple sequence repeat(SSR) marker-assisted selection(MAS). Z550 carr...An elite backcrossed inbred line Z550 with increased grains per panicle was identified from advanced backcrosses between Nipponbare and Xihui 18 by simple sequence repeat(SSR) marker-assisted selection(MAS). Z550 carries 13 substitution segments distributed on chromosomes 1, 6, 7, 8, 9, 10, and 12, with an average substitution length of 1.68 Mb. Compared with the Nipponbare parental line, plant height, panicle length, spikelets per panicle, grains per panicle, and grain weight for Z550 were significantly increased. While the grain width of Z550 was significantly narrower, and the seed setting ratio(81.43%) was significantly lower than that of Nipponbare, it is still sufficient for breeding purposes. Quantitative trait loci(QTLs) mapping for important agronomic traits was conducted with the F_2 population derived from Nipponbare crossed with Z550 using the restricted maximum likelihood(REML) method. A total of 16, including 12 previously unreported QTLs were detected, with contribution rates ranging from 1.46 to 10.49%. Grains per panicle was controlled by 8 QTLs, 5 of which increased number of grains whereas 3 decreased it. qGPP-1, with the largest contribution(10.49%), was estimated to increase grains per panicle by 30.67, while q GPP-9, with the minimum contribution rate(2.47%), had an effect of increasing grains per panicle by 15.79. These results will be useful for further development of single segment substitution lines with major QTLs, and for research of their molecular functions via QTL cloning.展开更多
The vacuolar proton-pumping pyrophosphatase gene(VPP)is often used to enhance plant drought tolerance via genetic engineering.In this study,the drought tolerance of four transgenic inbred maize lines overexpressing Zm...The vacuolar proton-pumping pyrophosphatase gene(VPP)is often used to enhance plant drought tolerance via genetic engineering.In this study,the drought tolerance of four transgenic inbred maize lines overexpressing ZmVPP1(PH4CV-T,PH6WC-T,Chang7-2-T,and Zheng58-T)and their transgenic hybrids was evaluated at various stages.Under normal and drought conditions,the height and fresh weight were greater for the four transgenic inbred maize lines than for the wild-type(WT)controls at the germination and seedling stages.Additionally,the transgenic plants exhibited enhanced photosynthetic efficiency at the seedling stage.In irrigated and non-irrigated fields,the four transgenic lines grew normally,but with increased ear weight and yield compared with the WT plants.Moreover,the ear weight and yield of the transgenic hybrids resulting from the PH4CV-T×PH6WC-W and Chang7-2-T×Zheng58-W crosses increased in the non-irrigated field.Our results demonstrated that the growth and drought tolerance of four transgenic inbred maize lines with improved photosynthesis were enhanced by the overexpression of ZmVPP1.Moreover,the Chang7-2 and PH4CV transgenic lines may be useful for future genetic improvements of maize hybrids to increase drought tolerance.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
Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance...Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance and yield. In the present study, responses in growth traits, photosynthetic parameters, chlorophyll fluorescence and leaf micromorphological characteristics were evaluated in Y478 and Z58 subjected to water-deficit stress induced by PEG 6000. The derived line Z58 showed greater drought tolerance than Y478, which was associated with higher leaf relative water content (RWC), root efficiency, and strong growth recovery. Z58 showed a higher stomatal density and stomatal area under the non-stressed condition;in these traits, both genotypes showed a similar decreasing trend with increased severity of water-deficit stress. In addition, the stomatal size of Y478 declined significantly. These micromorphological differences between the two lines were consistent with changes in physiological parameters, which may contribute to the enhanced capability for growth recovery in Z58. A non-linear response of Fv/Fm to leaf RWC was observed, and Fv/Fm decreased rapidly with a further gradual decline of leaf RWC. The relationship between other chlorophyll fluorescence parameters (photochemical quenching and electron transport rate) and RWC is also discussed.展开更多
A cell line designated as Ca 761-86 has been established from the solid mouse mammary cancer (Ca 761) by suspension culture. It has been passaged for more than 212 generations. Moderate round cells were predominant an...A cell line designated as Ca 761-86 has been established from the solid mouse mammary cancer (Ca 761) by suspension culture. It has been passaged for more than 212 generations. Moderate round cells were predominant and most of them were mononuclear. Some characteristics of malignant cells and A-type viral-like particles were observed by electron microscopy. The results of cytochemical studies (DNA, RNA, SDH, 5’ AMPase, ACP etc.) were comparable to the ultramicroscopic results. It multiplied approximately 27.4 fold on day 5 with mitotic index reaching 1.8% on day 3. This cell line was a hyperdiploid with karyotype of 45 or 45, -2X, tril2, tri17, +M1-5. Cell agglutination was observed when treated with ConA (≥7 fig, ml). Spontaneous agglutination might also take place without adding any ConA. After 5×106 cells of Ca 761-86 suspension were transplanted into the normal inbred 615 mice by different ways (subcutan eous, intrafoot-pad or intraperitoneal), the transplan lability rate reached 100%.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
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
Morphine is a widely used analgesic, but its use in clinical precision medicine is limited by the variance in response among individuals. Although previous studies have shown that individual differences in morphine ca...Morphine is a widely used analgesic, but its use in clinical precision medicine is limited by the variance in response among individuals. Although previous studies have shown that individual differences in morphine can be explained in terms of pharmacodynamics and pharmacokinetics, genetic polymorphisms also play an important role. However, the genetic basis of different sensitivity and tolerance susceptibility to morphine remains ambiguous. Using 15 strains of inbred Genetic Diversity(GD) mice,a new resource with wide genetic and phenotypic variation, we demonstrated great variance in sensitivity to morphine analgesia and susceptibility to morphine tolerance between different GD strains. Among-i ndividual variance in response to morphine analgesia in the population can be modeled in GD mice. Two loci respectively may be associated with the among-i ndividual variance in morphine sensitivity and tolerance,confirming the role of genetic factors in among-i ndividual different responses to morphine. These results indicate that GD mice may be a potential tool for the identification of new biomarkers to improve the clinical administration of morphine.展开更多
Rice is the most significant global food security. Several biotic factors limit rice production, breeding biotic-resistant rice has, therefore, become an increasingly important goal. Two elite rice lines, IR71033-121-...Rice is the most significant global food security. Several biotic factors limit rice production, breeding biotic-resistant rice has, therefore, become an increasingly important goal. Two elite rice lines, IR71033-121-15 (IR71033) and IR57514-PMI-5-B-1-2 (IR57514), provide potential genes for biotic stress resistance traits. In this study, genotyping by sequencing (GBS) for single nucleotide polymorphism (SNP)-based linkage map construction was used to detect quantitative trait loci (QTLs) for blast (BL), bacterial blight (BB), whitebacked planthopper (WBPH), and brown planthopper (BPH) resistance. IR71033 was derived from Oryza minuta and carried BL, BB, WBPH, and BPH resistance QTLs. IR57514 is a well-adapted rainfed lowland line that carries BL and BB resistance QTLs. Two sets of recombinant inbred line (RIL) populations derived from crosses of KDML105 × IR71033 and KDML105 × IR57514 were used to dissect the genetic basis of disease and insect pest resistance. The RIL populations were evaluated for BL, BB, WBPH, and BPH resistance from 2016 to 2018 at four rice research centers in Thailand. From these, we identified a large number of SNPs through GBS and constructed high-resolution linkage maps. By combining phenotypic evaluation with the GBS data, a total of 24 QTLs on four chromosomes were detected that confered pest resistance and explained 7.3% - 61.4% of the phenotypic variance. These findings should facilitate identifying novel resistance genes and applying marker-assisted selection for resistance to the four major rice pests investigated here. These strategies will improve the resilience and reliability of rice varieties adapted to the low-yielding environment of rainfed lowland areas worldwide.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
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
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
Improvement of seed yield of soybean(Glycine max(L.)Merr.)is generally achieved by combining morphological and yield-related traits,such as plant height(PH),node number on main stem(NN),pod number per plant(NP),seed n...Improvement of seed yield of soybean(Glycine max(L.)Merr.)is generally achieved by combining morphological and yield-related traits,such as plant height(PH),node number on main stem(NN),pod number per plant(NP),seed number per plant(NS),100-seed weight(HSW)and seed weight per plant(SWPP).Identifying quantitative trait loci(QTLs)for morphological and yield-related traits is therefore important for breeding.In this study,a four-way recombinant inbred line population comprising 160 lines derived from the cross(Kenfeng14×Kenfeng15)×(Heinong48×Kenfeng19)was planted in five different environments and morphological and yield-related trait data were used to identify QTLs by the inclusive composite interval mapping method.Totally 38 QTLs for PH,40 QTLs for NN,26 QTLs for NP,10 QTLs for NS,26 QTLs for HSW and 49 QTLs for SWPP were detected in 125 genomic regions.Single QTLs explained 2.17%-14.60%,2.00%-10.04%,2.37%-9.77%,2.62%-8.61%,0.47%-6.51%and 0.14%-12.39%of the phenotypic variation for PH,NN,NP,NS,HSW and SWPP,respectively.Among these 125 genomic regions,120 were newly associated with morphological and yield-related traits.The results would facilitate the molecular breeding of morphological and yield-related traits in soybean.展开更多
基金supported by a grant from the National High-Tech R&D Program of China (2014AA10A603, 2014AA10A604)a grant from the Youth Foundation in Sichuan, China (2011JTD0022)+1 种基金the special fund for China Agricultural Research System (CARS-01-08)the Provincial Specialized Funds for Innovation Ability Promotion in Sichuan, China (2013GXJS005)
文摘Grain appearance quality traits,measured as grain length(GL),grain width(GW),length to width ratio(LWR),grain thickness(GT) and the percentage of grain with chalkiness(PGWC),as well as 1 000-grain weight(TGW),are very important factors that contribute to rice grain quality and yield.To detect quantitative trait loci(QTLs) affecting these traits,we developed a set of recombinant inbred lines(RILs) derived from Gang46B(G46B) and K1075,a G46 B introgression line with lower PGWC.Based on a linkage map containing 33 simple sequence repeat(SSR) markers,a total of 15 additive QTLs governing six measured traits were identified on 4 chromosomes across two environments.Of these,the five major QTLs which controlled GW,LWR,GT,PGWC,and TGW,each explaining up to 44.30,55.29,62.30,30.94,and 28.78%of the variation,respectively,were found in the same interval of RM18004-RM18068 on chromosome 5.The G46 B alleles contributed to the increase in GW,GT and PGWC at all loci,as well as the increase in TGW at its major QTL locus.Significant interactions between additive QTL and the environment were found at most loci,in which the largest,accounting for15.06%of variation,was observed between qPGWC-5 and the environment.A total of 15 epistasis QTLs were detected for all the traits,and GL,GW and PGWC had significant epistasis QTLs based on environment interactions with minor effects.These results are valuable for future map-based cloning of the QTLs and the collaborative improvement of G46 B in grain appearance quality and yield.
基金the National Key Research Program of China(2016YFD0300503)the Special Fund for Agro-scientific Research in the Public Interest,China(201303102)+2 种基金the Key Research Program of Jiangsu Province,China(BE2016344)the Major Independent Innovation Project in Jiangsu Province,China(CX(15)1002)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristics of agronomic performance when comparing inter-sub-specific hybrid rice(IHR) and inbred japonica rice(IJR) under mechanical transplanting method. In 2013 and 2014, field experiments were conducted using IHR(Yongyou 2640) and IJR(Wuyunjing 24) under two cultivation patterns, that is, pot seedlings mechanically transplanted(PS) and carpet seedlings mechanically transplanted(CS). Grain yield, yield components, leaf area index(LAI), leaf area duration(LAD), aboveground biomass, crop growth rate(CGR), nitrogen(N) uptake, and N accumulation were investigated. When compared with CS, PS displayed significantly increased grain yield for both varieties because the larger sink size allowed higher N accumulation from panicle initiation to maturity. Moreover, total aboveground biomass under PS increased significantly compared with that under CS; that is, higher photosynthetic productivity resulted from a greater LAI and higher LAD during the grain filling stage. Higher N absorption capacity in the middle and late growth periods resulted in significantly enhanced total N uptake under PS. When compared with IJR for both treatments, IHR generated 75.2% more grain yield. However, the characteristics creating high yield of IHR were different from those of IJR. Greater aboveground biomass production as well as higher N uptake and accumulation created higher grain yield in IHR than in IJR. These results suggest higher yield could be achieved using PS with IHR, attributing to exploit both yield superiority and productive potential.
文摘Here, we analyzed whether the microRNA (miRNA) expression levels differ between maize inbred lines B73 and Mo17 and their reciprocal hybrids under salt and drought stress. We found that miR156, miR164, miR166, miR168, miR171 and miR319 are differentially expressed under abiotic stress. Interestingly, Mo17 × B73 showed the strongest change in miRNA expression in response to salt or drought stress, and was also the most resilient line when under abiotic stress in terms of water loss. In summary, our findings open the possibility that differential miRNA expression levels might be involved in heightened stress tolerance in maize hybrids.
文摘Lancaster Surecrop (LSC) germplasm in inbreds of the Lancaster heterotic group in China was mainly provided by the two inbreds Mo17 and Oh43. Furthermore, the source of LSC germplasm was severely restricted in two inbreds, C103 and Oh40B. The contents of LSC germplasm are 50% or less in inbreds of the group, with the existence of more than 20 non-LSC germplasms that results in the abundant genetic diversity in the group. Most inbreds of Mo17 subgroup contain 25 % - 50 % LSC, 12.5 % - 25 % Reid Yellow Dent (RYD)and 12.5% - 25% Iowa Goldmine germplasms in the ratio of 2:1:1, and most inbreds of Zi330 subgroup contain 12.5%-25% LSC, 6.25%- 12.5% RYD, 6.25%- 12.5% Minnesota # 13 and 25%- 50% Creole germplasms in the ratio of 2:1:1: 4. All the facts indicated that the germplasm base of the Lancaster heterotic group has stupendously changed and evolved away from actual LSC germplasm.
基金funded by the Natural Science Foundation of Yunnan Province(980006Z).
文摘Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining ability and genetic relationship of 25 inbreds extracted from five tropical maize populations and a land race, with four temperate maize inbreds (Huangzaosi, Mo17, B73 and Dan 340). The 25 tropical inbreds were crossed with the four temperate inbreds and evaluated. Lines from Suwan1 and POP28 had high general combining ability (GCA) for grain yield. The lines from POP32 (ETO) had the highest special combining ability (SCA) with B73; the average SCA value of the 5 lines was 879 kg/ha. The lines from Suwan1had the second-highest SCA (584 kg/ha) with Huangzaosi. The lines from Suwan1 had the greatest relative heterosis (20%) with B73, followed by the lines from POP32 (ETO) with B73 (19%). Five heterotic patterns have been identified from this study: Suwan1 × Reid, ETO × Reid, POP28 × Reid, POP28 × Ludahonggu, and Suwan1 × Lancaster.
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financially supported by National Key R&D Program (Grant No. 2016YFD0102102)Zhejiang Provincial Natural Science Foundation (Grant Nos. LY16C060002 and LQ17C130005)Zhejiang Agricultural Key Breeding Project (Grant No. 2016C02050-4) in China
文摘To identify stable quantitative trait loci(QTLs)responsible for sheath blight resistance,a recombinant inbred line mapping population consisting of 219 lines was developed by crossing Lemont and Yangdao 4.Average disease rating,average lesion length,maximum disease rating and maximum lesion length were assayed in six different environments.A total of 128 minor effect QTLs were detected by multiple interval mapping.These QTLs explained less than 11.2%of the phenotypic variations individually,and 106 QTLs were clustered in 20 QTL-rich regions/putative loci.Significant QTL×environment interactions were detected at three putative loci(qSBR11.1,qSBR11.2 and qSBR11.3),indicating that these three loci were not stable.The other 17 stable loci(qSBR1.1,qSBR1.2,qSBR2.1,qSBR2.3,qSBR3.1,qSBR3.2,qSBR3.5,qSBR3.6,qSBR5.1,qSBR7.1,qSBR8.1,qSBR9.1,qSBR9.2,qSBR9.3,qSBR12.1,qSBR12.2 and qSBR12.4)provided a foundation for marker-assisted selection in breeding.Analysis of allelic effect on the 20 putative loci identified 7 highly stable loci,including qSBR3.2,qSBR7.1,qSBR8.1,qSBR9.2,qSBR9.3,qSBR12.1 and qSBR12.2.
基金supported by the National Key R&D Program of China (2017YFD0100202)the Chongqing Science and Technology Commission Special Project, China (cstc2016shms-ztzx0017)the Southwestern University Basic Operating Expenses Special Innovation Team Project, China (XDJK2017A004)
文摘An elite backcrossed inbred line Z550 with increased grains per panicle was identified from advanced backcrosses between Nipponbare and Xihui 18 by simple sequence repeat(SSR) marker-assisted selection(MAS). Z550 carries 13 substitution segments distributed on chromosomes 1, 6, 7, 8, 9, 10, and 12, with an average substitution length of 1.68 Mb. Compared with the Nipponbare parental line, plant height, panicle length, spikelets per panicle, grains per panicle, and grain weight for Z550 were significantly increased. While the grain width of Z550 was significantly narrower, and the seed setting ratio(81.43%) was significantly lower than that of Nipponbare, it is still sufficient for breeding purposes. Quantitative trait loci(QTLs) mapping for important agronomic traits was conducted with the F_2 population derived from Nipponbare crossed with Z550 using the restricted maximum likelihood(REML) method. A total of 16, including 12 previously unreported QTLs were detected, with contribution rates ranging from 1.46 to 10.49%. Grains per panicle was controlled by 8 QTLs, 5 of which increased number of grains whereas 3 decreased it. qGPP-1, with the largest contribution(10.49%), was estimated to increase grains per panicle by 30.67, while q GPP-9, with the minimum contribution rate(2.47%), had an effect of increasing grains per panicle by 15.79. These results will be useful for further development of single segment substitution lines with major QTLs, and for research of their molecular functions via QTL cloning.
基金This study was supported by the National Key Project for Research on Transgenic Plants,China(2016Zx08003-O04)the Independent Innovation Project of Henan Academy of Agricultural Sciences,China(2060302).
文摘The vacuolar proton-pumping pyrophosphatase gene(VPP)is often used to enhance plant drought tolerance via genetic engineering.In this study,the drought tolerance of four transgenic inbred maize lines overexpressing ZmVPP1(PH4CV-T,PH6WC-T,Chang7-2-T,and Zheng58-T)and their transgenic hybrids was evaluated at various stages.Under normal and drought conditions,the height and fresh weight were greater for the four transgenic inbred maize lines than for the wild-type(WT)controls at the germination and seedling stages.Additionally,the transgenic plants exhibited enhanced photosynthetic efficiency at the seedling stage.In irrigated and non-irrigated fields,the four transgenic lines grew normally,but with increased ear weight and yield compared with the WT plants.Moreover,the ear weight and yield of the transgenic hybrids resulting from the PH4CV-T×PH6WC-W and Chang7-2-T×Zheng58-W crosses increased in the non-irrigated field.Our results demonstrated that the growth and drought tolerance of four transgenic inbred maize lines with improved photosynthesis were enhanced by the overexpression of ZmVPP1.Moreover,the Chang7-2 and PH4CV transgenic lines may be useful for future genetic improvements of maize hybrids to increase drought tolerance.
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.
文摘Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance and yield. In the present study, responses in growth traits, photosynthetic parameters, chlorophyll fluorescence and leaf micromorphological characteristics were evaluated in Y478 and Z58 subjected to water-deficit stress induced by PEG 6000. The derived line Z58 showed greater drought tolerance than Y478, which was associated with higher leaf relative water content (RWC), root efficiency, and strong growth recovery. Z58 showed a higher stomatal density and stomatal area under the non-stressed condition;in these traits, both genotypes showed a similar decreasing trend with increased severity of water-deficit stress. In addition, the stomatal size of Y478 declined significantly. These micromorphological differences between the two lines were consistent with changes in physiological parameters, which may contribute to the enhanced capability for growth recovery in Z58. A non-linear response of Fv/Fm to leaf RWC was observed, and Fv/Fm decreased rapidly with a further gradual decline of leaf RWC. The relationship between other chlorophyll fluorescence parameters (photochemical quenching and electron transport rate) and RWC is also discussed.
文摘A cell line designated as Ca 761-86 has been established from the solid mouse mammary cancer (Ca 761) by suspension culture. It has been passaged for more than 212 generations. Moderate round cells were predominant and most of them were mononuclear. Some characteristics of malignant cells and A-type viral-like particles were observed by electron microscopy. The results of cytochemical studies (DNA, RNA, SDH, 5’ AMPase, ACP etc.) were comparable to the ultramicroscopic results. It multiplied approximately 27.4 fold on day 5 with mitotic index reaching 1.8% on day 3. This cell line was a hyperdiploid with karyotype of 45 or 45, -2X, tril2, tri17, +M1-5. Cell agglutination was observed when treated with ConA (≥7 fig, ml). Spontaneous agglutination might also take place without adding any ConA. After 5×106 cells of Ca 761-86 suspension were transplanted into the normal inbred 615 mice by different ways (subcutan eous, intrafoot-pad or intraperitoneal), the transplan lability rate reached 100%.
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
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 the National Key R&D Program of China (2017YFA0105204)National Natural Science Foundation of China (81873963)Fundamental Research Funds of Chinese Academy of Medical Sciences (2016ZX310044)。
文摘Morphine is a widely used analgesic, but its use in clinical precision medicine is limited by the variance in response among individuals. Although previous studies have shown that individual differences in morphine can be explained in terms of pharmacodynamics and pharmacokinetics, genetic polymorphisms also play an important role. However, the genetic basis of different sensitivity and tolerance susceptibility to morphine remains ambiguous. Using 15 strains of inbred Genetic Diversity(GD) mice,a new resource with wide genetic and phenotypic variation, we demonstrated great variance in sensitivity to morphine analgesia and susceptibility to morphine tolerance between different GD strains. Among-i ndividual variance in response to morphine analgesia in the population can be modeled in GD mice. Two loci respectively may be associated with the among-i ndividual variance in morphine sensitivity and tolerance,confirming the role of genetic factors in among-i ndividual different responses to morphine. These results indicate that GD mice may be a potential tool for the identification of new biomarkers to improve the clinical administration of morphine.
文摘Rice is the most significant global food security. Several biotic factors limit rice production, breeding biotic-resistant rice has, therefore, become an increasingly important goal. Two elite rice lines, IR71033-121-15 (IR71033) and IR57514-PMI-5-B-1-2 (IR57514), provide potential genes for biotic stress resistance traits. In this study, genotyping by sequencing (GBS) for single nucleotide polymorphism (SNP)-based linkage map construction was used to detect quantitative trait loci (QTLs) for blast (BL), bacterial blight (BB), whitebacked planthopper (WBPH), and brown planthopper (BPH) resistance. IR71033 was derived from Oryza minuta and carried BL, BB, WBPH, and BPH resistance QTLs. IR57514 is a well-adapted rainfed lowland line that carries BL and BB resistance QTLs. Two sets of recombinant inbred line (RIL) populations derived from crosses of KDML105 × IR71033 and KDML105 × IR57514 were used to dissect the genetic basis of disease and insect pest resistance. The RIL populations were evaluated for BL, BB, WBPH, and BPH resistance from 2016 to 2018 at four rice research centers in Thailand. From these, we identified a large number of SNPs through GBS and constructed high-resolution linkage maps. By combining phenotypic evaluation with the GBS data, a total of 24 QTLs on four chromosomes were detected that confered pest resistance and explained 7.3% - 61.4% of the phenotypic variance. These findings should facilitate identifying novel resistance genes and applying marker-assisted selection for resistance to the four major rice pests investigated here. These strategies will improve the resilience and reliability of rice varieties adapted to the low-yielding environment of rainfed lowland areas worldwide.
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.
基金Supported by the Key Research and Development Project of Heilongjiang Province(GA21B009-06)。
文摘Improvement of seed yield of soybean(Glycine max(L.)Merr.)is generally achieved by combining morphological and yield-related traits,such as plant height(PH),node number on main stem(NN),pod number per plant(NP),seed number per plant(NS),100-seed weight(HSW)and seed weight per plant(SWPP).Identifying quantitative trait loci(QTLs)for morphological and yield-related traits is therefore important for breeding.In this study,a four-way recombinant inbred line population comprising 160 lines derived from the cross(Kenfeng14×Kenfeng15)×(Heinong48×Kenfeng19)was planted in five different environments and morphological and yield-related trait data were used to identify QTLs by the inclusive composite interval mapping method.Totally 38 QTLs for PH,40 QTLs for NN,26 QTLs for NP,10 QTLs for NS,26 QTLs for HSW and 49 QTLs for SWPP were detected in 125 genomic regions.Single QTLs explained 2.17%-14.60%,2.00%-10.04%,2.37%-9.77%,2.62%-8.61%,0.47%-6.51%and 0.14%-12.39%of the phenotypic variation for PH,NN,NP,NS,HSW and SWPP,respectively.Among these 125 genomic regions,120 were newly associated with morphological and yield-related traits.The results would facilitate the molecular breeding of morphological and yield-related traits in soybean.
