脱落酸对水稻种子萌发和秧苗生长的调控作用

用不同浓度ABA溶液浸泡稻种后观测稻种的发芽情况;用不同浓度ABA溶液喷施于稻苗上,调查稻苗的生长情况及干旱胁迫后稻株的有关生化指标。结果表明:低浓度ABA(0.5 mg/L～1.0 mg/L)处理水稻种子对其萌发无明显影响,但能有效控制根和芽的伸长生长,高浓度ABA(>5.0mg/L)对种子萌发和根、芽的伸长生长具有明显的抑制作用;经ABA处理的水稻秧苗株高增长率受到明显控制,苗高降低;ABA能有效减缓干旱胁迫期间秧苗叶片相对含水量的减少,提高秧苗的抗旱能力;在干旱胁迫过程中,经ABA处理的秧苗SOD、CAT活性和抗坏血酸含量明显高于对照(清水),MDA的含量则明显低于对照(清水)。

Effect of ABA on the Germination of Rice Seed and Growth of Its Seedling

The effect of ABA on the germination of rice seed, growth of rice seedling and drought resistance of rice seedling were studied. The results showed that ABA at lower concentration (less than 0. 5 mg/L -1.0 mg/L) has no effect on the seed germination, but could effectively inhibit the elongation of bud and roots. ABA at high concentration ( >5. 0 mg/L) effectively inhibited the seed germination and elongation of bud and root. ABA could inhibit the increment rate of plant height significantly, and the plant height was decreased. ABA could effectively enhance the relative water content in the leaves of rice seedling during the drought stress period, as well as enhance the tolerance of rice seedling to the drought stress, the activities of superoxid dismutase (SOD) and catalase (CAT) were found to be kept at higher levels in ABA-treated seedling leaves than that of the control (water) , the content of malondialdehyde ( MDA) was decreased in ABA-treated seedling leaves than that of the control (water) , while the ascorbic acid content was increased in ABA ?treated seedling leaves than that of control(water) .