Identification of combining ability loci for five yield-related traits in maize using a set of testcrosses with introgression lines

Abstract

Combining ability is essential for hybrid breeding in crops. However, the genetic basis of combining ability remains unclear and has been seldom investigated. Identifying molecular markers associated with this complex trait would help to understand its genetic basis and provide useful information for hybrid breeding in maize. In this study, we identified genetic loci of general combining ability (GCA) and specific combining ability (SCA) for five yield-related traits under three environments using a set of testcrosses with introgression lines (ILs). GCA or SCA of the five yield-related traits of the ILs was estimated by the performance of testcrosses with four testers from different heterotic groups. Genetic correlations between GCA of the traits and the corresponding traits per se were not significant or not strong, suggesting that the genetic basis between them is different. A total of 56 significant loci for GCA and 21 loci for SCA were commonly identified in at least two environments, and only 5 loci were simultaneously controlling GCA and SCA, indicating that the genetic basis of GCA and SCA is different. For all of the traits investigated, positive and significant correlations between the number of GCA loci in the ILs and the performance of the corresponding GCA of the ILs were detected, implying that pyramiding GCA loci would have positive effect on the performance of GCA. Results in this study would be useful for maize hybrid breeding.

Elucidation of the molecular responses of a cucumber segment substitution line carrying Pm5.1 and its recurrent parent triggered by powdery mildew by comparative transcriptome profiling

“…In the current study, we used a SSL to investigate PM resistance in cucumber. SSL508-28 possessed a segment from the PM resistant donor (Jin5-508), allowing for more precise detection of the PM responsive genes [34]. In PM inoculation tests conducted over 3 years, the resistance of SSL508-28 was found to be highly consistent and stable, suggesting that the introgressed fragment truly carried a PM resistant locus.…”

The effect of waterlogging on yield and seed quality at the early flowering stage in Brassica napus L.

“…In our experiment, the analysis of G × E revealed that there were no evident differences among the three environments. For most experiments which are about yield performance, the effect of environments is always significant because the sites are set at very different environment which are far away from each other to study the effect of environment on the yield (Xiang et al, 2001;Shi et al, 2009;Qi et al, 2013). In this case, the first thing to be considered about when designing the experiment is the effect of waterlogging on the yield.…”

The phenotypic predisposition of the parent in F1 hybrid is correlated with transcriptome preference of the positive general combining ability parent

“…It has being successfully applied in crop and livestock breeding for the evaluation of parent performance [3-5]. However, in spite of this, the genetic analysis of the GCA is very limited [6,7], and the molecular mechanism of the GCA has not been documented. In the present study, we found that certain phenotypes in rice F1 hybrids were always biased toward the positive GCA effect parents in the traits tested (r > 0.97, P <  3.80E-07).…”

“…Qi et al found that several genetic loci responding for GCA and SCA for five yield-related traits using a set of testcrosses with introgression lines (ILs) of maize under different environmental conditions. Total of 56 significant QTL GCA loci have been mapped [7]. These studies have revealed that GCA effects, like the traits, are genetically controlled.…”