seed dormancy
5.The main cause of its seed dormancy was afterripening of seed-embryo and seed-physiology. The mechanism of seed dormancy and germination was discussed. Seeds of two-year sand-storage treatment could be germinated up to 70% of surviving rate by means of freezing or GA+6-BA in 15 dyas, which shortened one year time of its seed dormancy.
6.The QTLs on chromosome 1 and 7 were detected in CSSL1 and CSSL2 populations simultaneously,QTL came from Asomonori, the moderate dormant cultivar,increased seed dormancy,and QTL from IR24,the weakly dormant cultivar,decreased seed dormancy. It can be deduced that there exist genes controlling seed dormancy at this region.

