高温强光下外源褪黑素对栝楼雌花生理生化特性的影响

为探讨高温强光下外源物质对栝楼雌花生理生化变化的影响,以2年生皖蒌9号为试验材料,研究叶面喷施200 μmol·L^-1褪黑素对高温强光下栝楼雌花的抗氧化酶活性、渗透调节物质、H₂O₂、相对电导率、花粉萌发率、坐果率和单果鲜质量的影响。结果表明,在高温强光下,外源物质褪黑素不仅能显著提高栝楼雌花SOD、POD、CAT和APX等抗氧化酶的活性,有效清除体内H₂O₂(与对照相比降低了34.5%),还能促进渗透调节物质合成和积累,与对照相比,外源褪黑素处理的雌花可溶性糖和脯氨酸含量分别增加了25.8%和45.5%。高温强光条件下,外源物质褪黑素还可有效提高栝楼花粉萌发率,促进栝楼坐果和果实膨大,栝楼坐果率提高了9.1百分点。综上,在高温强光下外源褪黑素能通过提高栝楼雌花抗氧化酶活性和渗透调节能力等,缓解高温危害,提高其坐果率。

Effects of exogenous melatonin on physiological and biochemical characteristics in female flowers of Trichosanthes kirilowii under high temperature and strong light

In order to explore the physiological and biochemical changes of exogenous substances on the female flowers of Trichosanthes kirilowii under high temperature and strong light in summer, two-year-old Wanlou 9 was used as material, the effects of 200 μmol·L^-1 melatonin on the activities of antioxidant enzymes, osmotic regulators, H₂O₂, relative conductivity, pollen germination, fruit setting rate and single fruit weight of T. kirilowii under high temperature and strong light were studied. The results showed that the exogenous melatonin significantly increased activities of SOD, POD, CAT and APX, eliminated 34.5% of H₂O₂ compared with the control of T. kirilowii under high temperature and strong light. Moreover, it also promoted the synthesis and accumulation of osmotic regulators. Soluble sugar and proline in female flowers treated with exogenous melatonin increased by 25.8% and 45.5%, respectively, compared with the control. The exogenous melatonin also increased the pollen germination rate, promoted the fruit setting and fruit enlargement, and increased the fruit setting rate of T. kirilowii by 9.1 percent under high temperature and strong light. Above all, exogenous melatonin could significantly relieve the high temperature hazards and improve the fruit-setting rate by increasing the antioxidant enzyme activity and osmotic regulation ability under high temperature and strong light.