高温对水稻抽穗扬花期生理特性的影响

Effects of high temperature stress on physiological characteristics of rice during heading and flowering period

以扬稻6号(中熟中籼)和南粳43(中熟晚粳)为材料,探讨了抽穗扬花期高温胁迫对水稻花粉活力、花粉萌发率以及剑叶有关理化特性的影响.结果表明:高温胁迫使两个品种水稻花粉萌发率和花粉活力显著下降,细胞内渗透调节物质脯氨酸(Pro)、可溶性糖、可溶性蛋白质含量以及剑叶叶绿素含量、超氧化物歧化酶(SOD)活性均明显降低,丙二醛(MDA)含量和质膜透性明显增加,抗坏血酸(AsA)、还原型谷胱甘肽(GSH)含量在胁迫初期略微增加,尔后迅速下降.在相同条件下,抽穗扬花期南粳43受高温的伤害始终小于扬稻6号.高温胁迫下水稻剑叶保持较高水平的MDA含量和质膜透性以及较低水平的Pro、可溶性糖、可溶性蛋白质、AsA,GSH和SOD的含量是水稻抗逆的生理基础.

The effects of high temperature stress on the physiological and biochemical characteristics of pollen and flag leaves of rice during heading and flowering period in Yangdao 6 and Nanjing 43 were studied.The results show that under high temperature stress,pollen germination rate and pollen vitality decreased significantly,the contents of osmotic adjustable organic substances（proline,soluble sugar and soluble protein）,chlorophyll and the activity of superoxide dismutase（SOD） decreased obviously,whereas malondialdehyde（MDA） content and the electrolyte leakage increased noticeably.The ascorbic acid（ASA） and glutathione（GSH） contents increased appreciably at early stage of high temperature stress,and then decreased rapidly.Under the same growth condition,the harmfulness of high temperature stress on Nanjing 43 was always less than Yangdao 6 during heading and flowering period.Higher chlorophyll content and proline,soluble sugar,soluble protein content,lower MDA content and electrolyte leakage in flag leaves of rice were the physiological basis of stress resistance in rice.