PHYSIOLOGICAL CHARACTERISTICS OF PRE-HARVEST SPROUTING OF HYBRID RICE IN SEED PRODUCTION

The high-sprouting CMS D69A and low-sprouting CMS D23A were used to cross with the restorer Shuhui 527 for comparing their physiological difference of seed pre-harvest sprouting(PHS). The results indicated that the seeds (F_0) pre-harvest ratio of D69A/Shuhui 527 was 44.84%, higher than that of D23A/Shuhui 527 (5.59%). From the 15~ th day after pollination to grain filling watery stage, the two styles of α-and β-amylase activity in seed of D69A/Shuhui 527 were all higher than that of D23A/Shuhui 527 for 10 d in the process inducing seed pre-harvest sprouting. Meanwhile, the ABA/GA content ratio of D69A/Shuhui 527 was shown a parabolic trend, but the ABA(GA content ratio of D23A/Shuhui 527 showed an anti-parabolic trend. By this token, GA content advantage of endogenous ABA/GA and a higher level of amylase activity in grains may be the major physiological characters of PHS in the production of hybrid rice.