Genetic dissection of heterosis using epistatic association mapping in a partial NCII mating design
نویسندگان
چکیده
Heterosis refers to the phenomenon in which an F1 hybrid exhibits enhanced growth or agronomic performance. However, previous theoretical studies on heterosis have been based on bi-parental segregating populations instead of F1 hybrids. To understand the genetic basis of heterosis, here we used a subset of F1 hybrids, named a partial North Carolina II design, to perform association mapping for dependent variables: original trait value, general combining ability (GCA), specific combining ability (SCA) and mid-parental heterosis (MPH). Our models jointly fitted all the additive, dominance and epistatic effects. The analyses resulted in several important findings: 1) Main components are additive and additive-by-additive effects for GCA and dominance-related effects for SCA and MPH, and additive-by-dominant effect for MPH was partly identified as additive effect; 2) the ranking of factors affecting heterosis was dominance > dominance-by-dominance > over-dominance > complete dominance; and 3) increasing the proportion of F1 hybrids in the population could significantly increase the power to detect dominance-related effects, and slightly reduce the power to detect additive and additive-by-additive effects. Analyses of cotton and rapeseed datasets showed that more additive-by-additive QTL were detected from GCA than from trait phenotype, and fewer QTL were from MPH than from other dependent variables.
منابع مشابه
Interacted QTL Mapping in Partial NCII Design Provides Evidences for Breeding by Design
The utilization of heterosis in rice, maize and rapeseed has revolutionized crop production. Although elite hybrid cultivars are mainly derived from the F1 crosses between two groups of parents, named NCII mating design, little has been known about the methodology of how interacted effects influence quantitative trait performance in the population. To bridge genetic analysis with hybrid breedin...
متن کاملGenetic dissection of main and epistatic effects of QTL based on augmented triple test cross design
The use of heterosis has considerably increased the productivity of many crops; however, the biological mechanism underpinning the technique remains elusive. The North Carolina design III (NCIII) and the triple test cross (TTC) are powerful and popular genetic mating design that can be used to decipher the genetic basis of heterosis. However, when using the NCIII design with the present quantit...
متن کاملGenetic Analysis and Heterosis for Viscosity Parameters in Rice (Oryza sativa L.) through North Carolina III Mating Design
This study was conducted to evaluate the gene effects, heritability, heterosis and identification of appropriate breeding methods for improving rice viscosity parameters, during 2014-2016 at Rice Research Institute of Iran. The progeny obtained from the North Carolina III mating design with their parents were planted in a randomized complete block design with three replications. Analysis of var...
متن کاملGenetic analysis of heterosis for yield and yield components in rapeseed (Brassica napus L.) by quantitative trait locus mapping.
The main objective in this research was the genetic analysis of heterosis in rapeseed at the QTL level. A linkage map comprising 235 SSR and 144 AFLP markers covering 2045 cM was constructed in a doubled-haploid population from a cross between the cultivar "Express" and the resynthesized line "R53." In field experiments at four locations in Germany 250 doubled-haploid (DH) lines and their corre...
متن کاملEstimation of Combining Ability and Gene Action for Agro-Morphological Characters of Rapeseed (Brassica Napus L.) Using Line×Tester Mating Design
Combining ability effects were estimated for different agronomic characters in line × tester crossing program comprising 21 hybrids produced by crossing 7 lines and 3 testers. Parents and hybrids differed significantly for general combining ability (GCA) and specific combining ability (SCA) effects, respectively. The variance due to GCA and SCA showed that gene action was predominantly additive...
متن کامل