人工接种CGMMV的增殖及其对西瓜光合作用的影响

摘要

为明确西瓜感染黄瓜绿斑驳花叶病毒CGMMV后病毒的增殖过程及其对光合作用的影响,本研究以辽宁省田间主栽西瓜品种‘京欣’为试材,测定了人工接种CGMMV后,西瓜植株体内病毒含量、光合色素、光合作用相关指标以及参与光合作用的关键酶活性的变化,结果显示:接种3d后,即可检测到病毒,24 d植株内病毒含量达最高;叶绿素a、叶绿素b及类胡萝卜素的含量均有所降低,叶绿素a在9d后均低于健康对照,而叶绿素b和类胡萝卜素在15d后明显低于健康对照,第18天时,健康对照的叶绿素b含量达接种处理的1.33倍;ALA脱水酶活性除第15天与对照无显著差异外,整个测定期间均低于健康对照,21 d时健康对照的ALA脱水酶的活性达29.9 U/h,为接种处理的2.18倍;PEP羧化酶的活性显著低于健康对照,测定期间接种处理的PEP羧化酶活性变化不大;乙醇酸氧化酶活性明显升高,测定期间其活性均显著高于健康对照;西瓜叶片的光合速率、气孔导度和蒸腾速率均远小于健康对照,而细胞间隙CO2浓度却比对照高,本研究为揭示西瓜感染CGMMV后的光合作用变化规律奠定了基础.%Studies were conducted with the watermelon cultivar ‘Jingxin’ in Liaoning Province.In order to reveal the viral multiplication process after watermelon was inoculated by Cucumber green mottle mosaic virus (CGMMV) and its influence on photosynthesis,some physiological and biochemical indexes such as concentration of virus and photosynthetic pigment,activity of key enzymes and related physiological indexes were studied.The results indicated that the virus was detected on the 3rd day after watermelons were inoculated by CGMMV,and the concentration of virus was highest on the 24th day.Meanwhile the concentrations of chlorophyll a,chlorophyll b and carotenoids were significantly lower than those of the control.The concentration of chlorophyll a was lower than that of healthy control after 9 days.The concentration of chlorophyll b and carotenoids were significantly decreased on the 15th day.On the 18th day,the concentration of chlorophyll b was equivalent to 1.33 times of the control.In this study,the activity of ALA anhydrase was tested.It was 29.9 U/h,much higher than that of the control and equivalent to 2.18 times on the 21st day.The tests showed that the activity of phosphoenolpyruvate carboxykinase was significantly lower than that of the control,but the activity of glycolate oxidase was highcr than that of the control during the experimental period.The photosynthesis (Pn),stomatal conductance (Gs) and transpiration rate (Tr) of watermelon leaves were lower than those of the control,while the concentration of CO2 in the cells was higher than that of the control.This research established foundation for revealing the change in photosynthesis after watermelon was inoculated by CGMMV.