早粳中组8号种子休眠的研究

Research on the seed dormancy of zhongzu 8(japonica)

中组8号（japonica）是一个具有深度休眠的优质早粳品系，休眠期为45天。该试验分别对其完整种子、剥壳种子及经干热预处理的完整种子进行试剂处理，并测试了其种子浸出液对水稻非休眠品种种子萌发的影响。研究表明，①55℃干热处理7天、0.1mol／LHNO3或0.1mol／LHC1浸种1天及其剥壳处理都能有效的打破其休眠，50ppMGA3效果不大，0.1mol／LKNO3及0．4％H2O2无效；②对于剥壳种子，0．1mol／LHNO3或0.1mol／LHC1有毒害作用，GA3有明显的促萌作用，KNO3或H2O2仍然无效；③干热处理后的完整种子对一些试剂的反应与未处理的相似，但该处理不能增强高酸度对完整种子的促萌作用；④H2O2具有依赖GA3的促萌作用，但这种作用机理尚不清楚；⑤抑萌物质存在于胚及胚乳中，种壳中不存在。通过分析认为中组8号的种子休眠主要由种壳透气性差引起，同时内源激素水平也对萌发产生一定程度的不利因素。

Zhongzu 8 is a early season japonica variety which have high quality and deep dormancy, it sdormancy period is 45 days. In that experiment,the dormancy character of it is researched by dryheating, dehulling and treatment of some reagents, and the effect of the infusion of the seeds on the getmination of the seeds of the non-dormancy variety Zhongyouzao 1 were tested. It indicated that: (1)the dormancy of its intact seeds can be effectively broken by dehulling, or by soaking in 0. 1mol/LHNO3 or HC1,or by 7 days of dry-heating at 55℃, but soaking in 50 PPM GA3 for 24h has slighteffect, and 0. 1mol/L KNO3 or 0. 4 % H2O2 has no effect; (2)for dehulled seeds, 0. 1mol/L HNO3 and0.1 mol/L HC1 have slight harmful, only GA3 has dominant effect,KNO3 or H2O2 has no effect yet;(3)dry-heating, after which the intact seeds have the same tendency as be fore on response to almostall reagonts, cannot improve the effect of high acidity (PH = 1 ); (4 )the germination - improving effectof H2O2 depeneds on GA3 ; (5) the infusion of the seeds can inhibit the germination of the non-dormancy seeds. The major reason of the domancy is that the seed hull restricts the entry of oxygen,and the minor is the slight unbalance of the endogenous hormones.