A 3×3 complete diallel cross comprising three families of the clam Meretrix meretrix（P1, P2 and P3） was used to determine the combining ability of parental families and heterosis of F1 under indoor and openair ...A 3×3 complete diallel cross comprising three families of the clam Meretrix meretrix（P1, P2 and P3） was used to determine the combining ability of parental families and heterosis of F1 under indoor and openair environments for growth traits. Analysis of variance for shell length and whole body weight indicated highly significant cross effects, environment effects and the interaction of cross by environment. General combining ability（GCA） and specific combing ability exhibited great variation among crosses and between two environments. Pooled over environments, P2 was the top combiner among the three parental families for both traits studied. The cross of P1 and P3 had the highest SCA. Additionally, significant reciprocal effects were observed. For individual environment, about half of the crossbred combinations showed favorable Mid-parent heterosis（MPH）（〉1%） for the shell length and whole body weight. Our data has shown that non-additive genetic and reciprocal effects constituted the major sources of genetic variation for both shell length and whole body weight, which indicates that crossbreeding among selective families could further explore the heterotic effects.展开更多
Fifteen capsicum combinations were made with 6 parents by （1/2）n（n-1） diallel crossing. Genetic parameters in the resistance to TMV, CMV, phytophthora blight, bacterial spot of these combinations were studied by H...Fifteen capsicum combinations were made with 6 parents by （1/2）n（n-1） diallel crossing. Genetic parameters in the resistance to TMV, CMV, phytophthora blight, bacterial spot of these combinations were studied by Hayman. The results indicated that the resistance to TMV, CMV and bacterial spot conformed genetically to the “additive-dominant” model but the resistance to phytophthora blight did not and significant epistatic dominance effect existed in it. F1 hybrid＇s resistance to CMV was controlled by homozygous dominant gene （s）, but resistance to bacterial spot by heterozygous one （s）. There were little, or no sum of dominant effect and genomes controlling the dominant expression of F1 hybrids in its phytophthora blight resistance.展开更多
A promising way to uncover the genetic architectures underlying complex traits may lie in the ability to recognize the genetic variants and expression transcripts that are responsible for the traits' inheritance.H...A promising way to uncover the genetic architectures underlying complex traits may lie in the ability to recognize the genetic variants and expression transcripts that are responsible for the traits' inheritance.However,statistical methods capable of investigating the association between the inheritance of a quantitative trait and expression transcripts are still limited.In this study,we described a two-step approach that we developed to evaluate the contribution of expression transcripts to the inheritance of a complex trait.First,a mixed linear model approach was applied to detect significant trait-associated differentially expressed transcripts.Then,conditional analysis were used to predict the contribution of the differentially expressed genes to a target trait.Diallel cross data of cotton was used to test the application of the approach.We proposed that the detected differentially expressed transcripts with a strong impact on the target trait could be used as intermediates for screening lines to improve the traits in plant and animal breeding programs.It can benefit the discovery of the genetic mechanisms underlying complex traits.展开更多
Vitamin A deficiency has become a worldwide problem.Biofortified foods can potentially be an inexpensive,locally adaptable,and long-term solution to dietary-nutrient deficiency.In order to improve the β-carotene cont...Vitamin A deficiency has become a worldwide problem.Biofortified foods can potentially be an inexpensive,locally adaptable,and long-term solution to dietary-nutrient deficiency.In order to improve the β-carotene content in maize grain by breeding and minimize vitamin A deficiency,a complete diallel cross was designed with eight inbred lines of maize,and 64 combinations were obtained in this study.The experimental combinations were planted in Yunnan and Sichuan provinces,respectively,with a random complete block design.The β-carotene contents in the grains of the experimental materials were analyzed by high-performance liquid chromatography.Among the tested materials,the effect difference of general combining ability of the β-carotene content was significant;however,the effect difference of the special combining ability and the reciprocal effect were not significant.The β-carotene content of maize grain was not influenced significantly by the cross and the reciprocal cross.There was a significant correlation about the β-carotene content in the maize grains between the F 1 and their parents.The combinations with high β-carotene content were obviously influenced by the environment,and the mean value of β-carotene content for the experimental materials planted in Ya＇an of Sichuan was higher than that planted in Yuanjiang of Yunnan,with the results being significant at the 0.01 level.展开更多
基金The National High-Tech R&D Program of China(863 Program)under contract No.2012AA10A410the Key Technologies R&D Program of Jiangsu Province under contract No.BE2011372
文摘A 3×3 complete diallel cross comprising three families of the clam Meretrix meretrix（P1, P2 and P3） was used to determine the combining ability of parental families and heterosis of F1 under indoor and openair environments for growth traits. Analysis of variance for shell length and whole body weight indicated highly significant cross effects, environment effects and the interaction of cross by environment. General combining ability（GCA） and specific combing ability exhibited great variation among crosses and between two environments. Pooled over environments, P2 was the top combiner among the three parental families for both traits studied. The cross of P1 and P3 had the highest SCA. Additionally, significant reciprocal effects were observed. For individual environment, about half of the crossbred combinations showed favorable Mid-parent heterosis（MPH）（〉1%） for the shell length and whole body weight. Our data has shown that non-additive genetic and reciprocal effects constituted the major sources of genetic variation for both shell length and whole body weight, which indicates that crossbreeding among selective families could further explore the heterotic effects.
文摘Fifteen capsicum combinations were made with 6 parents by （1/2）n（n-1） diallel crossing. Genetic parameters in the resistance to TMV, CMV, phytophthora blight, bacterial spot of these combinations were studied by Hayman. The results indicated that the resistance to TMV, CMV and bacterial spot conformed genetically to the “additive-dominant” model but the resistance to phytophthora blight did not and significant epistatic dominance effect existed in it. F1 hybrid＇s resistance to CMV was controlled by homozygous dominant gene （s）, but resistance to bacterial spot by heterozygous one （s）. There were little, or no sum of dominant effect and genomes controlling the dominant expression of F1 hybrids in its phytophthora blight resistance.
基金supported by the National Basic Research Program of China(2011CB109306)the National High Technology Research and Development Program of China(2009ZX08009-004B,2011AA10A102)+2 种基金the CNTC(110200701023)the YNTC(08A05)the earmearked fund for Modern Agro-industry Technology Reasearch System(CARS-18-05)
文摘A promising way to uncover the genetic architectures underlying complex traits may lie in the ability to recognize the genetic variants and expression transcripts that are responsible for the traits' inheritance.However,statistical methods capable of investigating the association between the inheritance of a quantitative trait and expression transcripts are still limited.In this study,we described a two-step approach that we developed to evaluate the contribution of expression transcripts to the inheritance of a complex trait.First,a mixed linear model approach was applied to detect significant trait-associated differentially expressed transcripts.Then,conditional analysis were used to predict the contribution of the differentially expressed genes to a target trait.Diallel cross data of cotton was used to test the application of the approach.We proposed that the detected differentially expressed transcripts with a strong impact on the target trait could be used as intermediates for screening lines to improve the traits in plant and animal breeding programs.It can benefit the discovery of the genetic mechanisms underlying complex traits.
基金supported by the Harvest-Plus China Program,the National High-Tech R&D Program of China(2011AA10A103)the Sichuan Maize Breeding Program in the 12th Five-Year Plan,China
文摘Vitamin A deficiency has become a worldwide problem.Biofortified foods can potentially be an inexpensive,locally adaptable,and long-term solution to dietary-nutrient deficiency.In order to improve the β-carotene content in maize grain by breeding and minimize vitamin A deficiency,a complete diallel cross was designed with eight inbred lines of maize,and 64 combinations were obtained in this study.The experimental combinations were planted in Yunnan and Sichuan provinces,respectively,with a random complete block design.The β-carotene contents in the grains of the experimental materials were analyzed by high-performance liquid chromatography.Among the tested materials,the effect difference of general combining ability of the β-carotene content was significant;however,the effect difference of the special combining ability and the reciprocal effect were not significant.The β-carotene content of maize grain was not influenced significantly by the cross and the reciprocal cross.There was a significant correlation about the β-carotene content in the maize grains between the F 1 and their parents.The combinations with high β-carotene content were obviously influenced by the environment,and the mean value of β-carotene content for the experimental materials planted in Ya＇an of Sichuan was higher than that planted in Yuanjiang of Yunnan,with the results being significant at the 0.01 level.
