Rice collection and conservation activities in Thailand

Abstract

Local rice collection for the purpose of varietal improvement was pursured intensively during the period 1950-1967 and resulted in accumulation of 6,739 samples. If classified by endosperm type, 2,122 (31.5%) were glutinous and 4,619 or (68.5%) were non-glutinous. Based on the area where collected, 229 (3.4%) , 5,888 (87.4%) , and 622 (9.2%) of the samples were upland, lowland, and floating types, respectively. These were originally evaluated for yield and grain quality by personnel at the rice experiment stations. Only those resulted in several government recommended varieties released to farmers some of which have persisted and are still grown extensively. Local collections, which did not show sufficient promise to be released as varieties but appeared valuable for future breeding programs, together with prize-winning varieties from local rice competition exhibits and foreign introductions were maintained as germplasm by the rice experiment stations. It was necessary to store the seed samples at room temperature and replant every year or two to maintain viability. Since 1972, with the availability of an air conditioned room at the Bangkhen Rice Station, all collections have been given genetic stock numbers, maintained and characterized at Bangkhen, Bangkok. At Present, there are 3,050 accessions of which 2,434 have been cataloqued. About 63% of the collection involves germination and unsuitable storage facilities. Since 1966 the collection of indigenous varieties has been utilized for studies such as protein content, chemical and physical properties of the grain, resistance to some diseases and insects, and tolerance to problem soils. Factors concerned in the genetic deterioration of rice have been discussed. It is suggested that collection should be intensified especially in remote areas and those places where the HYV’s are spreading rapidly. However, the problems of financial support, good storage facilities, and well-trained personnel need to be solved before such work begins.