Quantitative studies for investigating variation and its effect on heterosis of rice

Abstract

An important step in plant breeding programs is identification of parents that are genetically<br />distant from each other, to find crossing combinations with better prospects of hybrid vigor. The<br />potential of identifying genetically distant parents depends on genetic diversity of population. 58 lines<br />of rice from diverse origins have been employed to study genetic variation in order to identify the<br />most effective components of grain yield. Using cluster analysis, the lines were classified into three<br />distinct classes; some of classes containing lines from different origins. Factor analysis has been<br />conducted to identify important components of variation and contributions of traits in each factor.<br />Based on factor analysis, 6 components were identified, explaining ~82% of observed variation.<br />Evaluation of heterosis of crosses, whose parents were selected based on genetic distances (GD),<br />showed that maximum heterosis was obtained for crosses containing the furthest lines. All together,<br />our results support the idea that the level of correlation between hybrid performance and genetic<br />divergence is depends on the germplasm used.