叶面喷施吲哚乙酸对油菜蕾薹期渍水的缓解效应

以油菜品种秦优7号(敏感)和苏油4号(耐渍)为材料,通过盆栽试验研究吲哚乙酸(IAA)对油菜蕾薹期渍水的缓解效应。蕾薹期渍水持续10d,渍水结束后,叶面喷施浓度为0.1mmol/L的IAA,随后的0~15d调查油菜的生理变化。结果发现:渍水后生物量和叶片光合色素含量降低;谷胱甘肽、抗坏血酸含量和超氧化物歧化酶活性升高;丙二醛含量升高;蔗糖合成酶、蔗糖磷酸合成酶活性上升,蔗糖和可溶性糖含量增加。渍水结束后喷施IAA,对敏感的秦优7号缓解效应更明显;叶片中的光合色素含量升高,5d后显著恢复生长;蔗糖磷酸合成酶活性降低,降低蔗糖含量;蔗糖合成酶活性降低,减少蔗糖的分解;尤其是喷施15d后IAA对渍水胁迫的缓解作用最明显,苏油4号根干重显著增加,而秦优7号的根干重和茎干重均显著增加。叶面喷施IAA有效缓解单株角果数、每角粒数和产量的降低,但对抗氧化系统影响较小。

Alleviation effects of IAA foliar spray on waterlogging stressed rapeseed at budding stage

To understand the alleviation effect of indole-3-acetic acid (IAA) on waterlogging stressed rapeseed at budding stage, pot experiment was carried out to investigate the growth and physiology of stressed Brassica napus cv Qingyou 7 (susceptive) and Suyou 4 (tolerant) plants before and after IAA (0.1 mmol/L) foliar spray. Results showed that 10 days of waterlogging inhibited rapeseed growth, biomass and chlorophyll content decreased. The increased physiological index included enzyme activities of SOD (superoxide dismutase), sucrose synthase, sucrose phosphate synthase, contents of GSH (glutathione), AsA (acrylonitrile styrene acrylate copolymer), MDA (malondialdehyde) and soluble sugar. When IAA sprayed after waterlogging, the alleviation effects were significant, especially on susceptive cultivar Qingyou 7. The leaf photosynthetic pigment contents were increased, which started promoting plant growth 5d after spray. SPS (sucrose phosphate synthase) activity decreased, resulting reduced sucrose. Decreased SS (sucrose synthase) activity reduced sucrose decomposition. After 15d of spray, root dry weight of both cultivars increased significantly, and stem dry weight increased in the susceptive. Yield traits recovered significantly, especially on pods per plant and seeds per pod. But the effect of IAA after waterlogging was less effective on oxidation system.