Genetic Diversity of Common Wild Rice Collected from Various Regions of Thailand

Abstract

Common wild rice (Oryza rufipogon Griff.) was found in Thailand and reported to be the ancestor of cultivated rice. It is an important genetic resource for rice breeding programs. This study was conducted to evaluate genetic structure within and among populations of common wild rice from different regions of Thailand.  Thirteen common wild rice populations were collected from natural habitats and near rice fields. Samples were grown in a pot experiment, 20 plants per populations at Agronomy Department, Faculty of Agriculture, Chiang Mai University.  Leaf samples were collected individually for DNA analysis using 5 microsatellite markers. The results showed that gene diversity (h) of populations ranged from 0.036 to 0.181 (average 0.125), percent polymorphic loci (%p) from 10.34 to 72.41% (average 42.48%), Shannon index (I) from 0.054 to 0.289 (average 0.194). The highest genetic diversity within population was observed in population from Nakhonnayok province (NY1) (h = 0.181, %P = 72.41) and the lowest was observe in population from Wangjao, Tak province (TAK2) (h = 0.036, %P = 10.34). However, very high genetic differentiation among populations was found (G_ST = 0.449), suggesting that conservation of one or a fews populations could not represent for all populations. Thus, in situ conservation should be practiced individually in each location.