Allelic Distribution in Some of Dwarfing Genes in Iranian Wheat (Triticum aestivum L.) Genotypes

Decrease the plant height using the Rht genes is one of the main strategies to improve the resistance to lodging and fertilization and to increase the productivity in wheat. In Iran, like to other parts of world, these genes are entered to new introduced and released varieties. To study allelic diversity of two main dwarf genes (Rht-D1b and Rht-B1b) and their effects on morphological traits of 98 Iranian wheat cultivars, this study was conducted in filed and molecular level using specific STS-PCR primers. Correlation analysis among morphological traits such as plant height, final leaf number, spike length and days to heading with dwarfism alleles was done. Results showed that the highest percentage of allelic composition was related to Rht B1-b/Rht D1-a with 66.33%. Also 82.65% of the studied cultivars at least carried one of the dwarfism alleles that it verify the entrance of dwarfism genes into Iranian wheat cultivars. Only plant height had negative and significant correlation with dwarfism alleles (r=-0.571**). The results of cluster analysis showed that genotypes were classified into 3 groups. The first group, have Rht B1-b/Rht D1-a genotype, Group II have Rht B1-a/Rht D1-b genotype and the third group have Rht B1-a/Rht D1-a genotype. Proper using of these genes in breeding programs can improve lodging resistance and also increase grain yield in wheat.