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

Document Type: Research Paper

Authors

1 Department of Agronomy and plant Breeding, Faculty of Agriculture, Gorgan University of Agricultural Sciences and Natural Resources, Beheshti St., P.O. Box 386, Gorgan, Iran.

2 Department of Plant Pathology, Faculty of Agriculture, Gorgan University of Agricultural Sciences and Natural Resources, Beheshti St., P.O. Box 386, Gorgan, Iran.

3 Cotton Research Institute of Iran, Gorgan, Iran.

Abstract

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

Keywords