Evaluation of low temperature germinability of 377 national rice accessions

The poorer low temperature germinability（LTG）of rice cultivars in the early cropping-season is one of the main factors limiting direct seeding in the double cropping regions in South China. Screening rice germplasm with strong LTG and breeding rice variety with strong LTG is the most economical and effective way to solve this issue. To identify rice germplasm with strong LTG，377 rice accessions from 56 countries and regions were subjected to 13℃ and their germination rates at low temperature were evaluated. The results showed that LTG of these rice accessions varied from 0 to 98.0% and the average germination rate was 37.6% with 76.4% of variation coefficient. 21 accessions had a LTG over 90%. Significant differences in LTG were observed among the three types of rice，indica，Aus and japonica. The average LTG of indica was highly significantly higher than that of japonica and Aus（ P ＜ 0.01），respectively，and the average LTG of japonica was significantly higher than that of Aus（ P ＜ 0.05）. The results provide a good basis for screening of rice germplasm with strong low temperature germinabilityand the 21 rice accessions with LTG over 90% could be good materials for breeding and gene discovery associated with strong low temperature germinability in rice.