General and specific combining abilities in a maize (Zea mays L.) test-cross hybrid panel: relative importance of population structure and genetic divergence between parents

Abstract

General and specific combining abilities of maize hybrids between 288 inbred lines and three tester lines were highly related to population structure and genetic distance inferred from SNP data. Many studies have attempted to provide reliable and quick methods to identify promising parental lines and combinations in hybrid breeding programs. Since the 1950s, maize germplasm has been organized into heterotic groups to facilitate the exploitation of heterosis. Molecular markers have proven efficient tools to address the organization of genetic diversity and the relationship between lines or populations. The aim of the present work was to investigate to what extent marker-based evaluations of population structure and genetic distance may account for general (GCA) and specific (SCA) combining ability components in a population composed of 800 inter and intra-heterotic group hybrids obtained by crossing 288 inbred lines and three testers. Our results illustrate a strong effect of groups identified by population structure analysis on both GCA and SCA components. Including genetic distance between parental lines of hybrids in the model leads to a significant decrease of SCA variance component and an increase in GCA variance component for all the traits. The latter suggests that this approach can be efficient to better estimate the potential combining ability of inbred lines when crossed with unrelated lines, and limits the consequences of tester choice. Significant residual GCA and SCA variance components of models taking into account structure and/or genetic distance highlight the variation available for breeding programs within structure groups.

Diversity and heterotic patterns in North American proprietary dent maize germplasm

“…Flint germplasm is available in the ex-PVP panel primarily through Pioneer Hi-Bred International. The Flint heterotic subgroup is complemented in hybrids by the Iodent heterotic subgroup (Larièpe et al, 2017). The true "Flint" seed characteristic has been purged to maintain the dominant, marketdriven dent phenotype.…”

Genetic Analysis of Morpho-Physiological Characteristics of Sunflower Under Stress and Non-Stress Drought Conditions

“…However, Jocić, Miladinović, & Kaya (2015), Jocković et al (2018), and Makanda et al (2014) analyzed gene effects of inbred lines using line x tester method and they showed that non-additive gene effects were more important for seed yield. Larièpe et al (2017) also observed the after that gene component was more important than the additive component in managing seed yield in sunflower. In addition, Saba, Khan, Sadaqat, & Rana (2016) reported the importance of dominant genes for seed yield in this crop.…”

Doubled haploid based parental lines are most suitable in predicting heterosis using microsatellites and in development of highly heterotic F1hybrids inBrassica oleracea

“…Our results are in conformity with Su et al [73] who also reported no significant association between genetic distances and SCA in chrysanthemum. However, Tian et al [78], Lariepe et al [44] reported significant correlation between total GD and SCA for length of terminal raceme in rapeseed, for grain yield and plant height in maize, respectively. Thus the association of GD with SCA is complicated.…”

“…Among different biometrical approaches, line × tester analysis appears to be ideal for estimating GCA effects of lines and testers, SCA effects of cross combinations, and providing information about nature of gene actions [17, 20, 41]. The extent of heterosis has been reported to be vary with mode of reproduction, genetic distance of parents, traits under investigation, developmental stage of plant and prevailing environment [27, 34, 38, 40, 44, 73]. The pair-wise parental genetic distance (GD) has been suggested as a good indicator of per se hybrid performance and recognition of heterotic groups [27, 34, 38, 40, 44, 73].…”

“…The extent of heterosis has been reported to be vary with mode of reproduction, genetic distance of parents, traits under investigation, developmental stage of plant and prevailing environment [27, 34, 38, 40, 44, 73]. The pair-wise parental genetic distance (GD) has been suggested as a good indicator of per se hybrid performance and recognition of heterotic groups [27, 34, 38, 40, 44, 73]. Different approaches are available to determine genetic distance depending upon morphological traits, horticultural data, biochemical characteristics and DNA markers based genotypic data [33, 55].…”