Biplot Analysis of Genotype by Environment for Cooking Quality in Hybrid Rice: A Tool for Line × Tester Data

A study of combining ability for improving rice cooking quality was carried out via genotype plus genotype × environment (GGE) biplot. Four restorer lines and three male sterile lines were used to obtain F1 in a line × tester trial at the Rice Research Institute, Amol, Iran in 2009. GGE biplot analysis showed that Neda and IR56 were the best general combiners for amylose content (AC), whereas Nemat and IR28 had the highest general combining ability (GCA) effects for gelatinization temperature (GT), and IR58 and IR59 showed the highest GCA effects in terms of gel consistency (GC). Meanwhile, IR58 and IR59 showed large specific combining ability (SCA) effects for AC, while Neda and SA13 had high SCA effects for GT. Nemat and IR28 had large SCA effects for GC. Because intermediate levels of AC, GT and GC are ideal, Nemat × IR59 was considered as the best possible cross. Based on these results, the GGE biplot showed good potential for identifying suitable parents, heterotic crosses and the best hybrids in line × tester data.