To investigate the genetic variation patterns of multiple traits in Pinus sibirica half_sibling families introduced to the Greater Khingan Range,this study aims to establish a comprehensive trait evaluation system bas...To investigate the genetic variation patterns of multiple traits in Pinus sibirica half_sibling families introduced to the Greater Khingan Range,this study aims to establish a comprehensive trait evaluation system based on genetic parameters and identify fast-growing,high-quality genetic materials.The findings provide scientific support for advanced-generation seed orchard development and multiobjective genetic improvement.A total of 66 half-sibling families from a 26-year-old trial plantation of the Tomsk seed source were evaluated.Eleven traits were measured,including growth traits(tree height,diameter at breast height,volume,and crown width),morphological traits(lateral branch diameter),wood quality traits(Pilodyn value),and needle traits(fresh weight,dry weight,moisture content,needle length,and needle width).Genetic parameters were estimated using variance component decomposition.Superior families with favorable performance in both growth and wood density traits were identified using Best Linear Unbiased Prediction(BLUP)weighted by genetic correla-tion coefficients.Additionally,individual tree selection was conducted based on growth traits using the index selection method.Significant genetic differences among families(Z ratio>1.50)were observed for 10 traits,including growth,wood density,and needle traits.The phenotypic coefficient of variation(PCV:5.05%-62.50%)and genetic coefficient of variation(GCV:2.19%-13.81%)exhibited substantial heterogeneity.Volume displayed the highest variation(PCV=62.50%,GCV=13.81%),while the highest family heritability was observed for the needle length-to-width ratio(h^(2)=78.30%),and the highest individual heritability was rec-orded for needle moisture content(H^(2)=95.22%).Genetic correlations analysis revealed strong positive associ-ations between volume and tree height(r=0.880),diameter at br-east height(r=0.968),and Pilodyn value(r=0.508).Using the BLUP method,13 superior families(e.g.,Families 59,11 and 51)were identified,with an average genetic gain in volume of 13.377%and a family retention rate of 70%,significantly exceeding the population mean(65.10%).Th-rough index selection,94 elite individual trees were selected,52.14%of which originated from superior families.The genetic gain in individual tree volume reached 26.80%,with the within family gain for elite individuals increasing to 28.47%.This study establishes the first multitrait genetic evaluation model for P.sibirica and proposes a“familyindividual”collaborative selection strategy.The selected superior families achieved avolume genetic gain of 3.864%-32.307%and an overall geneticgain of 2.729%-20.069%,while elite individual trees exhibited a volume genetic gain of 16.328%-52.716%.These findings would provide critical technical support for multi-objective breeding and seed orchard development in cold-temperate coniferous species.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
The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different f...The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different from the previous reports have been concluded: (1)both the degrees of freedom of the orthogonal terms C2 and C3 are m, (2)the denominator in the F test to C2 and C3 is the error mean of square between plots.展开更多
基金funded by the Key Science and Technology Program of the State Forestry Administration(Project No.:2001-31(1))the Scientific Research Project of Greater Khingan Range Forestry Group Co.,Ltd.(Project No.:s2023001)。
文摘To investigate the genetic variation patterns of multiple traits in Pinus sibirica half_sibling families introduced to the Greater Khingan Range,this study aims to establish a comprehensive trait evaluation system based on genetic parameters and identify fast-growing,high-quality genetic materials.The findings provide scientific support for advanced-generation seed orchard development and multiobjective genetic improvement.A total of 66 half-sibling families from a 26-year-old trial plantation of the Tomsk seed source were evaluated.Eleven traits were measured,including growth traits(tree height,diameter at breast height,volume,and crown width),morphological traits(lateral branch diameter),wood quality traits(Pilodyn value),and needle traits(fresh weight,dry weight,moisture content,needle length,and needle width).Genetic parameters were estimated using variance component decomposition.Superior families with favorable performance in both growth and wood density traits were identified using Best Linear Unbiased Prediction(BLUP)weighted by genetic correla-tion coefficients.Additionally,individual tree selection was conducted based on growth traits using the index selection method.Significant genetic differences among families(Z ratio>1.50)were observed for 10 traits,including growth,wood density,and needle traits.The phenotypic coefficient of variation(PCV:5.05%-62.50%)and genetic coefficient of variation(GCV:2.19%-13.81%)exhibited substantial heterogeneity.Volume displayed the highest variation(PCV=62.50%,GCV=13.81%),while the highest family heritability was observed for the needle length-to-width ratio(h^(2)=78.30%),and the highest individual heritability was rec-orded for needle moisture content(H^(2)=95.22%).Genetic correlations analysis revealed strong positive associ-ations between volume and tree height(r=0.880),diameter at br-east height(r=0.968),and Pilodyn value(r=0.508).Using the BLUP method,13 superior families(e.g.,Families 59,11 and 51)were identified,with an average genetic gain in volume of 13.377%and a family retention rate of 70%,significantly exceeding the population mean(65.10%).Th-rough index selection,94 elite individual trees were selected,52.14%of which originated from superior families.The genetic gain in individual tree volume reached 26.80%,with the within family gain for elite individuals increasing to 28.47%.This study establishes the first multitrait genetic evaluation model for P.sibirica and proposes a“familyindividual”collaborative selection strategy.The selected superior families achieved avolume genetic gain of 3.864%-32.307%and an overall geneticgain of 2.729%-20.069%,while elite individual trees exhibited a volume genetic gain of 16.328%-52.716%.These findings would provide critical technical support for multi-objective breeding and seed orchard development in cold-temperate coniferous species.
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.
文摘The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different from the previous reports have been concluded: (1)both the degrees of freedom of the orthogonal terms C2 and C3 are m, (2)the denominator in the F test to C2 and C3 is the error mean of square between plots.
