Genetic Diversity of Thai Upland Rice Germplasm Based on Inter-Simple Sequence Repeats Marker

Upland rice is an important plant genetic resource for rice breeding programs due to the high level of genetic diversity with inter-simple sequence repeats (ISSR), drought tolerance and resistance to diseases and pests in Thailand. The aim of this study was to investigate the genetic diversity of local rice at the molecular level using ISSR markers. The ISSR technique is simple based on high polymorphism in the genetic background. Fifty-four local rice accessions were genetically analyzed based on ISSR markers. All accessions were collected from upland areas in 14 provinces of Thailand. Thirty-seven primers were selected with 10 being high polymorphic primers. Ninety-six alleles were found in all germplasms with 53 polymorphic bands (55.35%). The ISSR841 primer had the highest number of bands (13), while ISSR834, ISSR835, ISSR841 and ISSR864 had the lowest number of bands (8). The similarity index was in the range 0.84-0.99. Clustering analysis of local rice using the unweighted pair group method with arithmetic mean produced two main groups. The matrix correlation was 0.86. This research should be useful for evaluating rice germplasms from various areas and can be used as a database for rice breeding programs in the future.