Study of genetic diversity of selected indigenous rice varieties of Mizoram

Abstract

Rice (Oryza sativa L.) is one of the most important crop and staple food for more than half of the World s human population. Landraces of indigenous rice varieties are primary sources of germplasm for rice improvement programs since they contain a considerable level of genetic diversity so that the knowledge on the genetic diversity of such cultivars is very important for the development of improved varieties. In the present study, indigenous rice varieties of Mizoram, Northeast India were analyzed for seed morphology, seed storage protein profiling, and genetic diversity. Results revealed variation in grain length, width, and weight. Protein profiling showed similarity coefficient of 0.7064 indicated that genetic similarity existed respect to seed storage protein in the studied cultivars. Genetic diversity analysis using SSR markers revealed a total of 63 alleles. High levels of gene diversity and PIC value were observed. This high value of PIC indicated that the SSR markers used in this study are good markers for rice genetic diversity analysis. Among the markers used, RM1, RM154, RM131, RM135, and RM72 were identified as the most polymorphic loci markers. The Biruchuk cultivar was found to be the most genetically diverse cultivar with expected heterozygosity index of 0.3382 and the least gene diversity was found in Buhban zam with expected heterozygosity index of 0.0158. The UPGMA trees based on microsatellite diversity showed the grouping of rice cultivars into three clusters. The populations possessing high genetic diversity such as Biruchuk, Kawnglawng, Baimasa, etc. and genetically diverse varieties like Buhban home and Mangbuh, etc. can be utilized in rice breeding programs. Some cultivars exhibited a low level of genetic diversity suggesting necessary action with respect to conservation strategies. The present finding can be useful for selecting suitable rice lines for breeding programs and germplasm conservation of indigenous rice varieties of Mizoram.