DA-6对高温胁迫下黄灯笼辣椒幼苗的影响

Effects of DA-6 on Capsicum chinense Jacq.Seedlings Subjected to High Temperature

以海南黄灯笼辣椒"热辣2号"为试验材料,分别对幼苗喷施10、20、30、40、50 mg/L的DA-6,再进行高温胁迫处理,研究不同浓度的DA-6对缓解黄灯笼辣椒幼苗高温胁迫的作用。结果表明:喷施DA-6的辣椒幼苗各项生理指标较对照存在显著差异;喷施30 mg/L的DA-6时,幼苗的叶色值、根系活力、MDA含量、SOD活性和脯氨酸含量等指标综合反应较好,与其他处理差异显著。高温胁迫下,DA-6可有效增强黄灯笼辣椒幼苗的光合能力,喷施30 mg/L DA-6的辣椒幼苗净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)与对照相比均有所提高,分别提高了0.46、1.69、1.37倍;其PSⅡ最大荧光效率(Fv/Fm)、PSⅡ量子产量(Yield)、非光化学淬灭(qN)与光化学淬灭(qP)均显著高于对照。因此,DA-6能够缓解高温胁迫对黄灯笼辣椒幼苗的影响,其最适宜浓度为30 mg/L。

‘Rela No.2’ seedlings were sprayed with different concentrations of DA-6（10 mg/L,20 mg/L,30 mg/L,40 mg/L,50 mg/L）,and then subjected to high temperature to explore its effects on high temperature.The results showed that the seedlings demonstrated significant differences in physiological indices with DA-6 application compared with CK （DA-6 absence）.The content of chlorophyll and proline,root activity,SOD activity were higher in plants treated with concentration of 30 mg/L while MDA content was lower than any other treatments.Photosynthetic capacity was enhanced under high temperature in plants sprayed with DA-6.Photosynthetic rate （Pn）,stomatal conductance（Gs）and transpiration rate （Tr）was increased by 0.46 times,1.69 times and 1.37 times with the concentration of 30 mg/L.Fv/Fm and yield declined in seedlings under 6-day high temperature stress,while a significant increase in Fv/Fm with 20 mg/L DA-6 application on 6th day and in yield with 40mg/L DA-6 application on 4th day.Consequently,DA-6 spraying could reduce the impacts of high temperature on C.chinense Jacq.seedlings,and 30 mg/L was a proper concentration to high temperature alleviation comprehensively.