东乡野生稻苗期根系耐冷性生理生化特性

Biochemical and physiological characteristics of cold tolerance for roots in dongxiang wild Rice at the seedling stage

利用沙培法,研究了耐冷性不同的东乡野生稻和水稻品种幼苗在不同低温胁迫下根系活力、CAT活性、POD活性及MDA含量等根系生理活性的变化规律。结果表明:不同耐冷性水稻品种在3叶1心期经过3d的不同低温胁迫后,其根系生理活性发生了显著变化。强耐冷东乡野生稻和东野1号的根系活力、CAT活性和POD活性都随着低温胁迫的加剧而呈现先降后升再降的趋势;冷敏感的2个籼稻品种的根系活力和CAT活性则一直呈下降趋势,POD活性却先升后降;4个水稻品种的MDA含量都随着低温胁迫的加剧而加幅上升,但2个冷敏感品种的增幅更大。另外,常温或轻微低温胁迫下,冷敏感品种的CAT活性和POD活性不一定比强耐冷品种低。因此,认为低温胁迫下根系活力和根系MDA含量的相对大小可作为耐冷性生理鉴定指标。

With sandy culture, the effect of different low-temperature stress on physiological activity of rwt in rice seedlings of four varieties was analyzed. The results showed that their root physiological activity have changed clearly after different chilling stress lasting 3 days at seedling. The root activity and CAT activity and POD activity of Dongxiang wild rice and Dongye1 which have stronger tolerance to cold show off a trend which decrease at first and then increase while decrease in the end. The root activity and CAT activity of two cold-sensitive indica varieties show a declining trend and their POD adivity increase at first and then decease. The MDA content of four rice varieties is increasing with the rising of low-temperature stress while the MDA content of two cold-tolerant cultivars are less severely than the sensitive. The CAT activity and POD activity of sensitive varieties are not probably less than the strong ones. Therefore, we argue that root activity and MDA content are better appraisal method of cold tolerance.