Inheritance analysis of anther dehiscence as a trait for the heat tolerance at flowering in japonica hybrid rice (Oryza sativa L.)

Abstract

We analyzed the heredity of anther morphology in rice (Oryza sativa L.) using incomplete diallel crosses of six japonica restorer lines and eight cytoplasmic male-sterile (CMS) lines, and 48 F1 combinations resulting from these crosses. We analyzed four traits: the length of dehiscence formed in the apical (ADL) and basal (BDL) parts of the anther and the respective widths, ADW and BDW. The ratios of V gca (variance of general combining ability) to V sca (variance of specific combining ability) were 8.0 for BDL, 1.4 for BDW, 3.0 for ADL, and 2.8 for ADW. Narrow-sense heritability (H N 2 ) was 76.5 % for BDL, 37.9 % for BDW, 66.0 % for ADL, and 65.9 % for ADW. The effects of GCA (general combination ability) for BDL ranged from −67.0 to 68.9 μm (CMS lines) and from −33.4 to 43.0 μm (restorer lines); those for ADL were −46.7 to 44.0 μm (CMS lines) and −29.5 to 34.0 μm (restorer lines). We conclude that BDL and ADL have high heritability, and we can modify the size of apical and basal dehiscence by selecting suitable CMS and restorer lines.