Assessment of the Genetic Diversity of Joha Rice Germplasms by using Simple Sequence Repeat Markers

Abstract

Background: Joha Rice are aromatic rice landraces, having small to medium grain size, indigenous to Assam, India. Due to the introduction of high yielding hybrid varieties, many endemic rice landraces including Joha Rice, are in a verge of extinction, as these can only be conserved and maintained by repetitive cultivation. As there is a conflict of local names for these landraces, many landraces with similar morphological characters have been reported from various parts. Simple sequence repeat (SSR) markers with longer perfect repeats have earlier proved successful and essential in studying the genetic diversity among rice cultivars. The present study is aimed to evaluate the genetic relationship among fifteen (15) aromatic Joha rice landraces endemic to Upper Brahmaputra Valley, Assam.Methods: In the present investigation, different landraces of Joha rice were surveyed during 2016-2019. 15 landraces were selected, based on their morphological characters and local data. The collected germplasm of Joha rice was grown in the experimental plots and DNA from young, healthy leaves were isolated which were further used for determination of genetic diversity using SSR markers. Thirty-eight SSR markers were used to evaluate the genetic relationship among the fifteen aromatic rice landraces.Result: A total of 110 polymorphic alleles were detected by 34 markers across all the landraces, with an average of 3.25 per locus. The Polymorphic Information Content (PIC) ranged from 0.24 to 0.83, with an average of 0.5 for each marker. The marker RM154, RM454 and RM489 produced maximum six alleles showing PIC value of 0.82, 0.82 and 0.83, indicating a high polymorphism. UPGMA cluster analysis using Jaccard’s similarity index produced a dendrogram clustering the rice landraces in three major groups and five subgroups. Group II, which consisted of five sub-groups and 12 landraces, showed diverse genotypes. These landraces showed significant genetic similarities.