Contribution of Chromosomes 1HchS and 6HchS to Fertility Restoration in the Wheat msH1 CMS System under Different Environmental Conditions

Exploiting hybrid wheat heterosis has been long pursued to increase crop yield, stabilityand uniformity. Cytoplasmic male sterility (CMS) systems based in the nuclear-cytoplasmicincompatible interactions are a classic way for hybrid seed production, but to date, no definitivesystem is available in wheat. The msH1 CMS system results from the incompatibilitybetween the nuclear genome of wheat and the cytoplasmic genome of the wild barley Hordeumchilense. Fertility restoration of the CMS phenotype was first associated with the disomicaddition of the short arm of chromosome 6H from H. chilense. In further studies it wasobserved that chromosome arm 1HchS was also implicated, and the combination of genesin both chromosome arms restored fertility more efficiently. In this work we aim to dissectthe effect of each chromosome in fertility restoration when combined in different genomicbackgrounds and under different environmental conditions. We propose a model to explainhow restoration behaves in the msH1 system and generate valuable information necessaryto develop an efficient system for hybrid wheat production