Genetic variation and quantitative trait loci associated with developmental stability and the environmental correlation between traits in maize

There is limited experimental information about the genetic basis of micro-environmental variance (V-E) (developmental stability) and environmental correlations. This study, by using a population of maize recombinant inbred lines (RIL) and simple sequence repeat (SSR) polymorphic markers, aims at the following: firstly, to quantify the genetic component of the V-E or developmental stability for four traits in maize and the environmental correlation between these traits, and secondly, to identify quantitative trait loci (QTLs) that influence these quantities. We found that, when estimating variances and correlations and testing their homogeneity, estimates and tests are needed that are not highly dependent on normality assumptions. There was significant variation among the RILs in V-E and in the environmental correlation for some of the traits, implying genetic heterogeneity in the V-E and environmental correlations. The genetic coefficient of variation of the environmental variance (GCVV(E)) was estimated to be 20%, which is lower than estimates obtained for other species. A few genomic regions involved in the stability of one trait or two traits were detected, and these did not have an important influence on the mean of the trait. One region that could be associated with the environmental correlations between traits was also detected.