High nucleotide sequence variation of avirulent gene, , in Thai rice blast fungus population.

Rice blast disease, caused by , is one of the most importance diseases of rice production worldwide. The keyrole of defense mechanism to combat this fungus in rice follows the gene-for-gene concept, which a plant resistant () gene product recognizes a fungal avirulent () effector and triggers the hypersensitive response. However, the genes have been shown to be rapidly evolving resulting in high level of genetic diversity.

Genetic diversity of Indo-China rice varieties using ISSR, SRAP and InDel markers.

Rice is believed to have originated from Indo-China, area between China and India, and then spread throughout the world. The Indochina region mainly includes countries like Thailand, Laos and Vietnam, which are the world's major rice exporters. Rice varieties grown in this area are highly diverse due to their different environment, ecosystem and climatic conditions.