Genetic Diversity Studies on Selected Rice (Oryza Sativa) Genotypes Based on Amylose Content and Gelatinization Temperature

Abstract

Improving cooking and eating quality of rice is one of the important objectives of many breeding programs. The aim of the study was to carry out genetic diversity studies on selected rice (Oryza sativa L.) genotypes from Kenya and Tanzania based on amylose content and gelatinization temperature using microsatellite markers. Power marker version 3.25 and GenALEx version 6.5 softwares were used to analyze the data. The number of alleles per locus ranged from 2 to 4 alleles with an average of 2.75 alleles across 8 loci obtained in this study. The polymorphic information content (PIC) values ranged from 0.2920 (RM 202) to 0.6841 (RM 141) in all 8 loci with an average of 0.4697. Pair-wise genetic dissimilarity coefficients ranged from 0.9003 to 0.2251 with an average of 0.5627. Maximum genetic similarity was observed between R 2793 and BS 17, Supa and IR 64, R 2793 and ITA 310, Saro 5 and ITA 310, Saro 5 and R 2794. Minimum similarity of was observed between Wahiwahi and BW 196, IR 64 and BW 196. The dendogram based on cluster analysis by microsatellite polymorphism grouped the rice genotypes into 2 clusters effectively differentiating Kenyan and Tanzanian rice genotypes based on amylose content and gelatinization temperature. The results obtained suggested that use of microsatellite markers linked to Quantitative Trait Loci (QTLs) controlling these two traits could effectively be utilized for diversity analysis among diverse rice genotypes. Keywords: Oryza sativa; Oryza glaberrima; Heterozygosity; Germplasm; Genotypes