Adaptability of Thermosensitive Genetic Male Sterile Rice Lines in Thailand

Abstract

To determine the performance of thermosensitive genetic male sterile (TGMS) rice lines in Thailand, field experiments were conducted in Chiang Mai, Chiang Rai and Kamphaeng Phet. Six TGMS lines were planted during hot and cool seasons, and the results showed that TGMS lines respond to the prevailing temperatures at the time of the critical stage of TGMS lines at specific location. At Kamphaeng Phet, the six TGMS lines were all male sterile when planted in June 2002 and January 2003. Cool season planting in November 2003 that flowered in January to first week of February produced fertile pollen, and produced filled spikelets up to about 76.8%. At Chiang Mai, spikelet fertility of TGMS lines was observed as high as 77.4%. Kamphaeng Phet during cool season, and the high altitude areas in Chiang Mai are suitable locations for seed increase of TGMS lines. However, more experiments should be conducted to determine the suitable planting dates that could give highest spikelet fertility for seed multiplication of specific TGMS line. TGMS lines producing self-seeds under sufficient low temperature and showing sterility under temperature above 30°C indicated that TGMS lines could be used as parental line for developing two-line hybrid rice in Thailand.