Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines, and their 63 F_1 hybrids were chosen to compare the eleven traits of grain quality. Overall results showed that the frequency ...Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines, and their 63 F_1 hybrids were chosen to compare the eleven traits of grain quality. Overall results showed that the frequency of negative over-dominance, dominance and partial dominance was much higher than that of positive ones and heterosis, indicating that the values of F_1 hybrids were generally lower than the means of their parents in quality characteristics. There existed apparent disparity in grain quality performance among F_1 hybrids varied with the traits. The characteristics of chalky area percentage, chalky grain percentage, gel consistency and head rice recovery had a great variation in all kinds of tested heterosis indices including the mid-parent heterosis index, over high-value parent heterosis index and over low-value parent heterosis index, which suggested that special attention should be paid to the selection of F_1 hybrids in these traits in breeding. The mean values of F_1 hybrids were significantly lower than those of their higher parents in all the traits but close to or significantly lower than those of their mid-parent values except for kernel length and amylose content; and significantly higher than those of their lower parents except for brown rice recovery, milled rice recovery and gel consistency.展开更多
Background:Climate change and particularly global warming has emerged as an alarming threat to the crop productivity of field crops and exerted drastic effects on the cropping patterns.Production of cotton has been dr...Background:Climate change and particularly global warming has emerged as an alarming threat to the crop productivity of field crops and exerted drastic effects on the cropping patterns.Production of cotton has been dropped down to one million bales from 1.4 million bales since 2015 in Pakistan due to the increase in temperature at critical growth stages,i.e.,flowering and boll formation.Keeping in view the importance of cotton in the country,this study was conducted to investigate the genetic effects conferring heat tolerance in six populations(P1,P2,F1,F2,BC1 and BC2)developed from cross-1 and cross-2,i.e.,VH-282×FH-142 and DNH-40×VH-259.Results:The results revealed that cross-1 performed better in heat stress as compared with cross-2 for majority of the traits recorded.Boll weight and ginning outturn(GO-T)were highly effected under heat stress and had negative correlation with Relative cell injury(RCI).Boll weight,fiber length,fiber strength and fiber fineness were under the control of non-additive gene action,whereas RCI was controlled by additive gene effects.Lower values of genetic advance coupled with higher values of broad sense heritability for these traits except RCI confirmed the role of non-additive genetic effects.Duplicate types of epistasis were recorded for fiber strength in cross-1 in normal condition.However,complementary type of non-allelic interaction was recorded for fiber strength under normal condition,fiber fineness and RCI under heat stressed condition in cross-1.Likewise,boll weight,GOT and fiber length in populations derived from cross-2 in normal condition were also under the influence of complementary type of non-allelic interaction.Significant differences among values of mid parent and better parent heterosis for boll weight in both normal and heat stress condition provided the opportunity to cotton breeders for utilization of this germplasm for improvement of this trait through exploitation of heterosis breeding.Conclusion:Cross-1 performed better in heat stress and could be utiliz展开更多
Cabbage has significant heterosis and most commercial cultivars are hybrids.To explore genetic basis of cabbage heterosis and promote cabbage heterosis utilization,we constructed two populations by crossing 100 DH lin...Cabbage has significant heterosis and most commercial cultivars are hybrids.To explore genetic basis of cabbage heterosis and promote cabbage heterosis utilization,we constructed two populations by crossing 100 DH lines derived from a cabbage hybrid 01–20×96–100 with two female parents.Hybrids exhibited different extents of heterosis,the mean value of economic yield was 2.6 times bigger than parents.We identified 66 and 73 QTLs associated with mid-parent heterosis and transgressive heterosis of twelve yield-related traits,respectively.Some QTLs could be detected under the two-year experiment existed in two populations with different testers,showing relatively high phenotypic contribution rate(15.8%–20.0%).Heterosis QTLs exhibited clustered distribution in several cabbage chromosome regions.Two dominant genetic regions,mk300–316 and mk258–268,originated from the elite parent 01–20,exhibited significant genetic effects for yield-related heterosis,which were first identified.Three elite DH lines(D22,D46,D83)harboring these two dominant regions were selected as having strong heterosis in cabbage production.Candidate gene analysis revealed that some genes participating in biosynthetic processes of carbohydrates and some responses to auxin might affect cabbage yield heterosis.QTL identification and genetic dissection of yield-related traits provide new insights into the genetic effects of cabbage heterosis.展开更多
With the application of hybrid wheat, lodging is becoming one of the major factors limiting high yield in its production. However,few studies have focused on combining ability and heterosis analysis of stem-related tr...With the application of hybrid wheat, lodging is becoming one of the major factors limiting high yield in its production. However,few studies have focused on combining ability and heterosis analysis of stem-related traits. In this study, 24 crosses were made according to NCII genetic design, using the three(photo-sensitive male sterile lines)×eight(restorer lines) incomplete diallel crosses. The length of basal second internode(LBSI) and breaking strength of basal second internode(BSBSI)as well as other stem-related traits were used to perform the principal component analysis(PCA), combining ability and heterosis analysis. The PCA results showed that the variables could be classified into two main factors, which were named as the positive factor(factor 1) and the negative factor(factor 2), and accounted for 52.3 and 33.2%, respectively, of the total variance in different variables, combined with the analysis for index weight indicated that the factor 1-related traits play positive roles in lodging resistance formation of hybrids. Combining ability variance analysis indicated that its genetic performance was mainly dominated by additive gene effects, and the hybrid combinations with higher lodging resistance can be selected by using of 14 GF6085(R1), 14 GF6343-2(R4), 14 GF6937(R6), 14 GF7433-1(R7), and BS1086(M3),which are with the features with lower general combining ability(GCA) effects of factor 2-related traits whereas higher GCA effects of factor 1-related traits. The heterosis analysis showed that the wide range of heterosis varied with the traits and combinations, and GCA or specific combining ability(SCA) effects of factor 1-related traits except wall thickness of basal second internode(WTBSI) were positively and closely related to the heterosis of lodging resistance. Generally, the correlation coefficients of heterosis to GCA effects of sterile lines(GCAm) of factor 1-related traits are significantly higher than that to GCA of restorer lines(GCAr) and SCA, combined with the higher GCAm variance values o展开更多
The common carp(Cyrpinus carpio L.)is the oldest cultured and the most domesticated fish species,as well as one of the most important freshwater fishes in the world.However,scientific studies on evaluating the growth-...The common carp(Cyrpinus carpio L.)is the oldest cultured and the most domesticated fish species,as well as one of the most important freshwater fishes in the world.However,scientific studies on evaluating the growth-related quantitative traits in this fish are limited.Heritability,the most important parameter in selective breeding programs,was extensively studied for the growth-related traits.The values varied widely among the experiments and methods used because of the existence of common environmental,dominance and maternal effects.However,correlations in phenotypic and genetic levels first evaluated several years ago were limited.On the other hand,heterosis was widely reported and easily obtained for growth-related traits in the common carp.Meanwhile,genotype environment interaction and prediction of breeding values have been studied recently,and are very important in conducting selective breeding programs.The developmental quantitative genetics of growth-related traits was first analyzed in the common carp for reasonable selection during ontogeny.It is expected that genetic improvement will be achieved by carrying out direct selective breeding in the common carp.展开更多
Five molecular related indexes: MOL, SIM, d2, H0and PIC of 15 turbot parent pairs were estimated by using 10 SSR loci, which were used in correlation analysis with growth traits, DIL and DIW, of family filial from tho...Five molecular related indexes: MOL, SIM, d2, H0and PIC of 15 turbot parent pairs were estimated by using 10 SSR loci, which were used in correlation analysis with growth traits, DIL and DIW, of family filial from those 15 parent pairs.DIL and DIW were regressed on the MOL, SIM, d2, H0and PIC. Results showed MOL of five SSR loci(12, 17, 24, 81 and 85) and SIM of five loci(17, 21, 24, 81and 85) all shared significant positive correlation with DIL(r=0.482, P=0.035 and r=0.479, P=0.035, respectively); H0of six SSR loci(11, 17, 21, 24, 26 and 85) had significant positive correlation with DIW(r=0.551, P=0.017); PIC of two SSR loci(9and 26) had significant positive(r=0.519, P=0.024) correlation with DIL, while that and of four loci(17, 24, 27 and 85) had significant negative correlation(r=-0.519,P=0.024), with DIL. This present study suggested that filial growth expression could be predicted by using molecular related indexes in turbot breeding practice, and the accuracy of prediction depends on more SSR loci, especially associated with QTL.展开更多
The genetic distances among 18 cytoplasmic male sterile lines and 11 restorer lines were analyzed with molecular markers derived from yield-related functional genes. The correlation between parental genetic distance a...The genetic distances among 18 cytoplasmic male sterile lines and 11 restorer lines were analyzed with molecular markers derived from yield-related functional genes. The correlation between parental genetic distance and heterosis was investigated by analyzing the performance of 47 combinations. The results showed that the genetic distance was significantly correlated with yield heterosis （r=0.29^＊）, but not significantly correlated with heterosis for other traits, such as number of effective panicles per plant, seed setting rate, 1000-grain weight, number of grains per panicle and theoretical yield. However, the correlation coefficient was so small that the parental genetic distance could not to be used to predict heterosis.展开更多
文摘Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines, and their 63 F_1 hybrids were chosen to compare the eleven traits of grain quality. Overall results showed that the frequency of negative over-dominance, dominance and partial dominance was much higher than that of positive ones and heterosis, indicating that the values of F_1 hybrids were generally lower than the means of their parents in quality characteristics. There existed apparent disparity in grain quality performance among F_1 hybrids varied with the traits. The characteristics of chalky area percentage, chalky grain percentage, gel consistency and head rice recovery had a great variation in all kinds of tested heterosis indices including the mid-parent heterosis index, over high-value parent heterosis index and over low-value parent heterosis index, which suggested that special attention should be paid to the selection of F_1 hybrids in these traits in breeding. The mean values of F_1 hybrids were significantly lower than those of their higher parents in all the traits but close to or significantly lower than those of their mid-parent values except for kernel length and amylose content; and significantly higher than those of their lower parents except for brown rice recovery, milled rice recovery and gel consistency.
基金funding for this research was provided by Higher Education Commission,Pakistan
文摘Background:Climate change and particularly global warming has emerged as an alarming threat to the crop productivity of field crops and exerted drastic effects on the cropping patterns.Production of cotton has been dropped down to one million bales from 1.4 million bales since 2015 in Pakistan due to the increase in temperature at critical growth stages,i.e.,flowering and boll formation.Keeping in view the importance of cotton in the country,this study was conducted to investigate the genetic effects conferring heat tolerance in six populations(P1,P2,F1,F2,BC1 and BC2)developed from cross-1 and cross-2,i.e.,VH-282×FH-142 and DNH-40×VH-259.Results:The results revealed that cross-1 performed better in heat stress as compared with cross-2 for majority of the traits recorded.Boll weight and ginning outturn(GO-T)were highly effected under heat stress and had negative correlation with Relative cell injury(RCI).Boll weight,fiber length,fiber strength and fiber fineness were under the control of non-additive gene action,whereas RCI was controlled by additive gene effects.Lower values of genetic advance coupled with higher values of broad sense heritability for these traits except RCI confirmed the role of non-additive genetic effects.Duplicate types of epistasis were recorded for fiber strength in cross-1 in normal condition.However,complementary type of non-allelic interaction was recorded for fiber strength under normal condition,fiber fineness and RCI under heat stressed condition in cross-1.Likewise,boll weight,GOT and fiber length in populations derived from cross-2 in normal condition were also under the influence of complementary type of non-allelic interaction.Significant differences among values of mid parent and better parent heterosis for boll weight in both normal and heat stress condition provided the opportunity to cotton breeders for utilization of this germplasm for improvement of this trait through exploitation of heterosis breeding.Conclusion:Cross-1 performed better in heat stress and could be utiliz
基金financially supported by the Major State Research Development Program(Grant No.2016YFD0101702)the National Natural Science Foundation of China(Grant No.31872948)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIPIVFCAAS)。
文摘Cabbage has significant heterosis and most commercial cultivars are hybrids.To explore genetic basis of cabbage heterosis and promote cabbage heterosis utilization,we constructed two populations by crossing 100 DH lines derived from a cabbage hybrid 01–20×96–100 with two female parents.Hybrids exhibited different extents of heterosis,the mean value of economic yield was 2.6 times bigger than parents.We identified 66 and 73 QTLs associated with mid-parent heterosis and transgressive heterosis of twelve yield-related traits,respectively.Some QTLs could be detected under the two-year experiment existed in two populations with different testers,showing relatively high phenotypic contribution rate(15.8%–20.0%).Heterosis QTLs exhibited clustered distribution in several cabbage chromosome regions.Two dominant genetic regions,mk300–316 and mk258–268,originated from the elite parent 01–20,exhibited significant genetic effects for yield-related heterosis,which were first identified.Three elite DH lines(D22,D46,D83)harboring these two dominant regions were selected as having strong heterosis in cabbage production.Candidate gene analysis revealed that some genes participating in biosynthetic processes of carbohydrates and some responses to auxin might affect cabbage yield heterosis.QTL identification and genetic dissection of yield-related traits provide new insights into the genetic effects of cabbage heterosis.
基金supported by the National Key R&D Program of China(2016YFD0101601)the Beijing Natural Science Foundation,China(6194035)the Training Programme Foundation for the Beijing Municipal Excellent Talents,China(2017000020060G130)。
文摘With the application of hybrid wheat, lodging is becoming one of the major factors limiting high yield in its production. However,few studies have focused on combining ability and heterosis analysis of stem-related traits. In this study, 24 crosses were made according to NCII genetic design, using the three(photo-sensitive male sterile lines)×eight(restorer lines) incomplete diallel crosses. The length of basal second internode(LBSI) and breaking strength of basal second internode(BSBSI)as well as other stem-related traits were used to perform the principal component analysis(PCA), combining ability and heterosis analysis. The PCA results showed that the variables could be classified into two main factors, which were named as the positive factor(factor 1) and the negative factor(factor 2), and accounted for 52.3 and 33.2%, respectively, of the total variance in different variables, combined with the analysis for index weight indicated that the factor 1-related traits play positive roles in lodging resistance formation of hybrids. Combining ability variance analysis indicated that its genetic performance was mainly dominated by additive gene effects, and the hybrid combinations with higher lodging resistance can be selected by using of 14 GF6085(R1), 14 GF6343-2(R4), 14 GF6937(R6), 14 GF7433-1(R7), and BS1086(M3),which are with the features with lower general combining ability(GCA) effects of factor 2-related traits whereas higher GCA effects of factor 1-related traits. The heterosis analysis showed that the wide range of heterosis varied with the traits and combinations, and GCA or specific combining ability(SCA) effects of factor 1-related traits except wall thickness of basal second internode(WTBSI) were positively and closely related to the heterosis of lodging resistance. Generally, the correlation coefficients of heterosis to GCA effects of sterile lines(GCAm) of factor 1-related traits are significantly higher than that to GCA of restorer lines(GCAr) and SCA, combined with the higher GCAm variance values o
基金supported by the Natural Science Foundation of China(Grant No.30700622)the Shanghai Education Committee Project(No.07ZZ136)the Shanghai Leading Academic Discipline Project(No.Y1101).
文摘The common carp(Cyrpinus carpio L.)is the oldest cultured and the most domesticated fish species,as well as one of the most important freshwater fishes in the world.However,scientific studies on evaluating the growth-related quantitative traits in this fish are limited.Heritability,the most important parameter in selective breeding programs,was extensively studied for the growth-related traits.The values varied widely among the experiments and methods used because of the existence of common environmental,dominance and maternal effects.However,correlations in phenotypic and genetic levels first evaluated several years ago were limited.On the other hand,heterosis was widely reported and easily obtained for growth-related traits in the common carp.Meanwhile,genotype environment interaction and prediction of breeding values have been studied recently,and are very important in conducting selective breeding programs.The developmental quantitative genetics of growth-related traits was first analyzed in the common carp for reasonable selection during ontogeny.It is expected that genetic improvement will be achieved by carrying out direct selective breeding in the common carp.
文摘Five molecular related indexes: MOL, SIM, d2, H0and PIC of 15 turbot parent pairs were estimated by using 10 SSR loci, which were used in correlation analysis with growth traits, DIL and DIW, of family filial from those 15 parent pairs.DIL and DIW were regressed on the MOL, SIM, d2, H0and PIC. Results showed MOL of five SSR loci(12, 17, 24, 81 and 85) and SIM of five loci(17, 21, 24, 81and 85) all shared significant positive correlation with DIL(r=0.482, P=0.035 and r=0.479, P=0.035, respectively); H0of six SSR loci(11, 17, 21, 24, 26 and 85) had significant positive correlation with DIW(r=0.551, P=0.017); PIC of two SSR loci(9and 26) had significant positive(r=0.519, P=0.024) correlation with DIL, while that and of four loci(17, 24, 27 and 85) had significant negative correlation(r=-0.519,P=0.024), with DIL. This present study suggested that filial growth expression could be predicted by using molecular related indexes in turbot breeding practice, and the accuracy of prediction depends on more SSR loci, especially associated with QTL.
基金supported by the National High Technology Research and Development of China(Grant No.2009AA101101)the China National Jumping Plan of Agricultural Technology and Science the Tackling Key Subject of Rice Breeding in Sichuan Province,China(Grant No.YZGG2006-1)the Youth Foundation of Sichuan Academy of Agricultural Sciences,China(Grant No.2008QNJJ)
文摘The genetic distances among 18 cytoplasmic male sterile lines and 11 restorer lines were analyzed with molecular markers derived from yield-related functional genes. The correlation between parental genetic distance and heterosis was investigated by analyzing the performance of 47 combinations. The results showed that the genetic distance was significantly correlated with yield heterosis （r=0.29^＊）, but not significantly correlated with heterosis for other traits, such as number of effective panicles per plant, seed setting rate, 1000-grain weight, number of grains per panicle and theoretical yield. However, the correlation coefficient was so small that the parental genetic distance could not to be used to predict heterosis.
