To evaluate the relationships among clones and open pollinated families from the same plus trees and to select elite breeding materials,growth,and wood characteristics of 33-year-old Pinus korainsis clones and familie...To evaluate the relationships among clones and open pollinated families from the same plus trees and to select elite breeding materials,growth,and wood characteristics of 33-year-old Pinus korainsis clones and families were measured and analyzed.The results show that growth and wood characters varied significantly.The variation due to clonal effects was higher than that of family effects.The ratio of genetic to phenotypic coefficient of variation of clones in growth and wood traits was above 90%,and the repeatability of these characteristics was more than 0.8,whereas the ratio of genetic to phenotypic coefficient of variation of families was above 90%.The broad-sense heritability of all characteristics exceeded 0.4,and the narrow-sense family heritability of growth traits was less than 0.3.Growth characteristics were positively correlated with each other,but most wood properties were weakly correlated in both clones and families.Fiber length and width were positively correlated between clones and families.Using the membership function method,eleven clones and four families were selected as superior material for improved diameter growth and wood production,and two families from clonal and open-pollinated trees showed consistently better performance.Generally,selection of the best clones is an effective alternative to deployment of families as the repeatability estimates from clonal trees were higher than narrow-sense heritability estimates from open pollinated families.The results provide valuable insight for improving P.koraiensis breeding programs and subsequent genetic improvement.展开更多
The type 2 modified augmented design(MAD2) is an efficient unreplicated experimental design used for evaluating large numbers of lines in plant breeding and for assessing genetic variation in a population. Statistical...The type 2 modified augmented design(MAD2) is an efficient unreplicated experimental design used for evaluating large numbers of lines in plant breeding and for assessing genetic variation in a population. Statistical methods and data adjustment for soil heterogeneity have been previously described for this design. In the absence of replicated test genotypes in MAD2, their total variance cannot be partitioned into genetic and error components as required to estimate heritability and genetic correlation of quantitative traits, the two conventional genetic parameters used for breeding selection. We propose a method of estimating the error variance of unreplicated genotypes that uses replicated controls, and then of estimating the genetic parameters. Using the Delta method, we also derived formulas for estimating the sampling variances of the genetic parameters.Computer simulations indicated that the proposed method for estimating genetic parameters and their sampling variances was feasible and the reliability of the estimates was positively associated with the level of heritability of the trait. A case study of estimating the genetic parameters of three quantitative traits, iodine value, oil content, and linolenic acid content, in a biparental recombinant inbred line population of flax with 243 individuals, was conducted using our statistical models. A joint analysis of data over multiple years and sites was suggested for genetic parameter estimation. A pipeline module using SAS and Perl was developed to facilitate data analysis and appended to the previously developed MAD data analysis pipeline(http://probes.pw.usda.gov/bioinformatics_ tools/MADPipeline/index.html).展开更多
Tef [Eragrostis tef (Zucc.)Trotter] is an ancient and major cereal crop in Ethiopia. Increasing tef grain yield partly requires developing cultivars that are adapted to drought stress environment. An experiment was ca...Tef [Eragrostis tef (Zucc.)Trotter] is an ancient and major cereal crop in Ethiopia. Increasing tef grain yield partly requires developing cultivars that are adapted to drought stress environment. An experiment was carried out using 18 tef genotypes grown during September to December, 2010, under two water supply environments (stress during grain filling period, and non-stress) to identify genetic variation, heritability and correlations of grain yield and yield related traits. Broad-sense heritability values under respective stress and non-stress environments were grain yield (g/m2) 0.80 and 0.89, total biomass (g/m2) 0.89 and 0.73, harvest index 0.69 and 0.79, panicle weight (g/plant) 0.93 and 0.92, and seed weight (g/plant) 0.96 and 0.86. The correlations of grain yield under respective stress and non-stress environments were total biomass rp = 0.64, rg = 0.70, and rp = 0.48, rg = 0.56, harvest index rp = 0.70, rg = 0.64, and rp = 0.87, rg = 0.90, panicle weight rp = 0.98, rg = 1.00, and rp = 0.96, rg = 1.00, and seed weight/plant rp = 0.98, rg = 1.00, and rp = 0.90, rg = 1.00. The present experiment showed that either grain yield per se, or seed weight/plant could be used to improve grain yield under stress and non-stress environments.展开更多
基金supported by the Jilin Province Science and Technology Department Key Research and Development Project(20200402094N C)。
文摘To evaluate the relationships among clones and open pollinated families from the same plus trees and to select elite breeding materials,growth,and wood characteristics of 33-year-old Pinus korainsis clones and families were measured and analyzed.The results show that growth and wood characters varied significantly.The variation due to clonal effects was higher than that of family effects.The ratio of genetic to phenotypic coefficient of variation of clones in growth and wood traits was above 90%,and the repeatability of these characteristics was more than 0.8,whereas the ratio of genetic to phenotypic coefficient of variation of families was above 90%.The broad-sense heritability of all characteristics exceeded 0.4,and the narrow-sense family heritability of growth traits was less than 0.3.Growth characteristics were positively correlated with each other,but most wood properties were weakly correlated in both clones and families.Fiber length and width were positively correlated between clones and families.Using the membership function method,eleven clones and four families were selected as superior material for improved diameter growth and wood production,and two families from clonal and open-pollinated trees showed consistently better performance.Generally,selection of the best clones is an effective alternative to deployment of families as the repeatability estimates from clonal trees were higher than narrow-sense heritability estimates from open pollinated families.The results provide valuable insight for improving P.koraiensis breeding programs and subsequent genetic improvement.
基金partly supported by an A-base project funded by Agriculture and Agri-Food Canadathe TUFGEN project funded by Genome Canada and other stakeholdersfunds from the Western Grains Research Foundation
文摘The type 2 modified augmented design(MAD2) is an efficient unreplicated experimental design used for evaluating large numbers of lines in plant breeding and for assessing genetic variation in a population. Statistical methods and data adjustment for soil heterogeneity have been previously described for this design. In the absence of replicated test genotypes in MAD2, their total variance cannot be partitioned into genetic and error components as required to estimate heritability and genetic correlation of quantitative traits, the two conventional genetic parameters used for breeding selection. We propose a method of estimating the error variance of unreplicated genotypes that uses replicated controls, and then of estimating the genetic parameters. Using the Delta method, we also derived formulas for estimating the sampling variances of the genetic parameters.Computer simulations indicated that the proposed method for estimating genetic parameters and their sampling variances was feasible and the reliability of the estimates was positively associated with the level of heritability of the trait. A case study of estimating the genetic parameters of three quantitative traits, iodine value, oil content, and linolenic acid content, in a biparental recombinant inbred line population of flax with 243 individuals, was conducted using our statistical models. A joint analysis of data over multiple years and sites was suggested for genetic parameter estimation. A pipeline module using SAS and Perl was developed to facilitate data analysis and appended to the previously developed MAD data analysis pipeline(http://probes.pw.usda.gov/bioinformatics_ tools/MADPipeline/index.html).
文摘Tef [Eragrostis tef (Zucc.)Trotter] is an ancient and major cereal crop in Ethiopia. Increasing tef grain yield partly requires developing cultivars that are adapted to drought stress environment. An experiment was carried out using 18 tef genotypes grown during September to December, 2010, under two water supply environments (stress during grain filling period, and non-stress) to identify genetic variation, heritability and correlations of grain yield and yield related traits. Broad-sense heritability values under respective stress and non-stress environments were grain yield (g/m2) 0.80 and 0.89, total biomass (g/m2) 0.89 and 0.73, harvest index 0.69 and 0.79, panicle weight (g/plant) 0.93 and 0.92, and seed weight (g/plant) 0.96 and 0.86. The correlations of grain yield under respective stress and non-stress environments were total biomass rp = 0.64, rg = 0.70, and rp = 0.48, rg = 0.56, harvest index rp = 0.70, rg = 0.64, and rp = 0.87, rg = 0.90, panicle weight rp = 0.98, rg = 1.00, and rp = 0.96, rg = 1.00, and seed weight/plant rp = 0.98, rg = 1.00, and rp = 0.90, rg = 1.00. The present experiment showed that either grain yield per se, or seed weight/plant could be used to improve grain yield under stress and non-stress environments.
