外源ABA、Put和BR对亚适温条件下番茄幼苗叶片保护酶活性的影响

【研究目的】笔者研究了亚适温下不同浓度的脱落酸、腐胺、油菜素内脂对冷敏品种番茄“中蔬6号”幼苗保护酶活性的影响。【方法】选用不同浓度ABA、Put、BR溶液喷散番茄幼苗，清水处理作对照，每5d喷一次，共2次。然后在光照培养箱中模拟亚适温环境对番茄幼苗进行处理。【结果】亚适温下，番茄幼苗的MDA含量持续升高、SOD活性先升高后降低。对番茄幼苗进行适宜浓度的ABA、Put、和BR预处理，能够提高亚适温下番茄幼苗的SOD活性，降低MDA含量，有效地缓解亚适温引起的番茄幼苗叶片细胞的膜脂过氧化。降低MDA含量的最适浓度ABA为0.2mmol/L，Put为0.5mmol/L，BR为0.01mg/L；提高SOD活性的最适浓度ABA0.2mmol/L，Put为1.0mmol/L，BR为0.01mg/L。与对照相比，MDA含量分别降低47.7%、43.2%、42.2%，SOD活性分别提高29.2%、17.4%、28.6%；【结论】亚适温对番茄幼苗叶片细胞膜造成了伤害，膜脂过氧化产物MDA含量升高，SOD含量下降；喷施适宜浓度的ABA、Put、BR可以降低MDA含量，使SOD活性增加，减轻亚适温对番茄幼苗的伤害。

Effect of Extrinsic ABA, Put and BR on Protective Enzyme Activities of Tomato Seedlings Under Sub-optimal temperature

【OBJECTIVE】Effects on protective enzyme activities of tomato seedlings under different concentration of abscisic acid (ABA), putrescine (Put) and epibrassinolide (BR) were investigated. 【METHOD】The tomato seedlings were pre-treated with various concentration of ABA、Put、BR, and then treated with sub-optimal temperature stress in the growth chamber. 【RESULTS】The results showed that under sub-optimal temperature the content of MDA increased; SOD activity raised firstly and then decreased. Pre-treated with ABA, Put or BR can decrease MDA content and improved protective enzyme activities. The appropriate concentration which deceased MDA content most is ABA1(0.2mmol/L), Put2(0.5mmol/L) and BR2(0.01mg/L).The most suitable concentration to SOD activities is ABA1(0.2mmol/L), Put3(1.0mmol/L) and BR2(0.01mg/L). Compared with the control the activity of SOD increased in 29.2%、17.4%、28.6% respectively and MDA content decreased in 47.7%、43.2%、42.2% respectively. 【CONCLUSION】The tomato seedlings were hurt by sub-optimal temperature. ABA、Put、BR played a positive role in alleviating the effect of sub-optimal temperature on tomato seedlings.