Abstract
To test the ability of germination in soil at low temperatures among rice cultivars, chicken-breasted seeds were sown under various temperature and depth conditions. Native red rice cultivars, Awa-akamai, Toyama-zairai-aka, Arozz da terra, Beni-roman, Khao mak fay, Khao louk kheuy and Myae shay displayed a higher ability than Koshihikari. In addition, the Germination rate index (GRI) of the seeds sown at a depth of 1.0 cm and grown at 15°C was a good index for the ability. Backcross inbred lines (BC1F2) with the genetic background of Koshihikari were made from Awa-akamai and Arozz da terra, respectively, and these lines were grown under the above-mentioned conditions. The backcross inbred lines made from Awa-akamai displayed a higher ability than those made from Arozz da terra. Linkage between the germination ability and pericarp color was not found in the Awa-akamai-derived lines. Therefore, Awa-akamai could be advantageous as a genetic resource in breeding for the improvement of germination in soil at low temperatures.
