水稻制种中杂交种子穗发芽生理特性研究

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

利用易于穗发芽和不易穗发芽的水稻不育系D69A和D23A分别与蜀恢527配合制种,比较研究水稻制种中杂交种子(F0)穗发芽过程中的生理差异。结果表明:制种组合D69A/蜀恢527的F0种子穗发芽率为44.84%,比D23A/蜀恢527(穗发芽率为5.59%)易于穗发芽;在授粉后15d至完熟的籽粒灌浆期,经10d穗发芽诱导处理过程中,D69A/蜀恢527的F0种子α-淀粉酶活性和β-淀粉酶活性均明显高于D23A/蜀恢527;同时D69A/蜀恢527F0种子ABA/GA含量比呈抛物线趋势变化,而D23A/蜀恢527F0种子ABA/GA含量比基本呈反抛物线趋势变化。这表明在杂交水稻制种中,内源激素组成中的GA含量优势和高水平的淀粉酶活性是穗发芽主要的生理特征。

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.