Molecular Diversity Analysis of Traditional Rice Varieties (TRVs) in Nueva Vizcaya, Philippines

Abstract

Traditional rice varieties (TRVs) are valued genetic resources because they contain important economic value traits needed to integrate and broaden rice's genetic pool and variability.  In this study, twenty-seven TRVs including a check variety (Mindanao – RS25) collected from different locations in Nueva Vizcaya, were subjected to DNA analysis to explore the genetic diversity of the collection and to determine possible aromatic TRVs in the presence of the fgr-gene.  TRVs demonstrate high genetic diversity based on the relatively low similarity coefficient of 0.12 using 15 robust short tandem repeat (STR) markers. The molecular diversity analysis divided TRVs into two major clusters/groups with eight sub-clusters. Cluster I comprised 15 TRVs along with the check variety, mostly grown in high altitudes/elevation (>500masl) or cooler climatic conditions, the japonica types. Furthermore, in Cluster II, 12 TRVs were commonly cultivated at lower elevations (100-500 masl) or warmer climatic conditions (indica sub-species).  Moreover, the presence of the fgr-gene allele was observed in TRVs assessed at both production sites. Finally, the province of Nueva Vizcaya had a preliminary characterization and initial conservation of its TRVs, in which these diverse germplasms could offer a valuable gene pool and rare traits for future varietal improvement programs in rice.