杂交水稻种子闭颖度对种子耐储力的影响

The effect of husk closing degree of hybrid rice seed on resistance to ageing

用长粒型优质不育系Q1A为材料,通过人工老化与自然老化相结合,研究了种子闭颖度与耐储力的关系。闭颖不完全的种子由于千粒重低,胚乳储藏营养不足,不利于幼苗前期生长发育,成苗率较低;闭颖程度越低,耐储力越差。种子老化失活主要表现为:胚生命活力完全丧失产生不萌发的死种子;胚生命活力降低产生不能正常成苗的弱种子。闭颖程度较差的种子在衰老过程中产生的弱种子比例较大。闭颖度对种子耐储力影响的主要原因之一是颖壳阻碍了胚与氧气的接触,在真空条件下闭颖度对耐储力的影响减小。在100%的相对湿度、40℃的人工老化条件下处理5 d左右,对种子的老化程度与一次自然室温越夏的老化程度大致相当。

By means of artificial and natural ageing, the effect of husk closing degree on resistance to ageing of quality lndica CMS Q1 A was studied. When the husk is not closed in certain degree,the 1000-grain weight would decrease, the reserved nutrition in grain is not enough to support the ordinary growth of the young seedlings and the normal seedling percentage is low. When the closing degree is less,the resistance to ageing is lower.The lower resistance to ageing is indicated by died embryo, or vitality decreased embryo, increase the abnormal seedling percentage, decrease the seedling growth of dry weight per day; When fire closing degree is low, the amonnt of embryos of decreased vitality increase greatly. In vacuum condition, the effect of husk closing degree on resistance to ageing decreased. One of the main factor of husk closing degree affecting on resistance to ageing is the husk decreasing seed oxygenizing. Treated in the artificial ageing condition of 100% relative humility and 40 ℃ for 5 days, the ageing degree is equal to that during one summer natural temperature ageing condition.