UV-B辐射对不同发育时期辣椒主要果实品质的影响

Effects of UV-B Radiation on Main Fruit Quality of Capsicum annuum at Different Developmental Stages

为了探讨辣椒果实对UV-B辐射的生理应激反应机制,进一步阐述高UV-B辐射地区蔬菜果实品质劣变的机理,以紫外敏感型品种华美105和耐紫外型品种乐都长辣椒的幼果、青果、红果的果实为试材,研究0(CK),2,4,6 h不同UV-B辐射时长(剂量)对果实生长发育、还原型保护及营养品质相关的物质含量的影响。结果表明:随着辐射时间的延长,华美105青果期和红果期的单果质量、纵横径显著降低,从而抑制其果实的生长;2个品种各个生育期的果实中保护性物质Vc、总酚含量随着处理时长的延长逐渐增加,可溶性蛋白含量逐渐下降,其中6 h大幅度提高了Vc、总酚的含量,可溶性蛋白含量下降幅度最大,且华美105各处理下Vc、总酚、可溶性蛋白含量的变化幅度较乐都长辣椒要大;2个品种果实各生育期营养风味品质物质可溶糖随着辐射时间的延长其含量表现为先升高后降低的趋势,纤维素含量表现为先降低后升高的趋势。总之,UV-B对2个品种幼果期生长发育指标的影响不大,高剂量UV-B可以显著抑制紫外敏感型品种青果期和红果期的生长,并能显著增加2个品种Vc、总酚、纤维素等物质的含量,显著减小可溶性蛋白、可溶性糖含量;而低剂量的UV-B能大幅度提升可溶性糖含量,且上升或下降幅度为紫外敏感型品种>耐紫外性品种。因此,低于1/4致死剂量的UV-B能促进果实品质,高于1/2致死剂量的UV-B使得辣椒果实品质开始劣变。

In order to investigate the physiological stress response mechanism of pepper fruits to UV-B radiation and further elaborate the mechanism of fruit quality deterioration in vegetables in high UV-B radiation areas,the young fruits,green fruits and red fruits of UV-sensitive variety Huamei 105 and UV-resistant variety Ledu long pepper were selected as test materials.The effects of different UV-B radiation duration(dose)of 0(CK),2,4 and 6 h on fruit growth and development,prototype protection and nutrient quality related substances content were studied.The results showed that with the extension of radiation time,the single fruit weight and transverse diameter of Huamei 105 decreased significantly at the green and red fruit stages,which inhibited the fruit growth.The contents of protective substances Vc and total phenol in fruits of the two varieties at each growth stage increased gradually as the extension of treatment time,while the contents of soluble protein decreased gradually.The contents of Vc and total phenol significantly increased after 6 h,and the contents of soluble protein decreased the most.The contents of Vc,total phenol and soluble protein of Huamei 105 changed greater than those of Ledu long pepper.With the extension of radiation time,the content of soluble sugar showed a trend of first increasing and then decreasing,while the content of cellulose showed a trend of first decreasing and then increasing.In conclusion,UV-B had little effect on the indexes in the young fruit stage of the two varieties.High-dose UV-B could significantly inhibit the growth of the UV-sensitive varieties at the green and red fruit stages,and significantly increase the contents of Vc,total phenol,cellulose and other substances in the two varieties,and significantly reduce the contents of soluble protein and soluble sugar.However,low dose UV-B could significantly increase the soluble sugar content,and the increase or decrease amplitude was higher in UV-sensitive varieties than in UV-resistant varieties.Therefore,lower than 1/4 lethal dose of UV-B can promote fruit quality,and higher than 1/2 lethal dose of UV-B can make pepper fruit quality start to deteriorate.