叶面喷施1-MCP缓解辣椒幼苗高温伤害的机理研究

Mechanisms of Foliar-spraying 1-MCP to Alleviate Injury of Pepper Seedlings Caused by High Temperature

以‘纽内姆黄帅’辣椒为试验材料,研究高温胁迫下叶面喷施1–甲基环丙烯(1-MCP)缓解幼苗伤害的可能机理。结果表明,高温胁迫对辣椒幼苗的生长具有明显的抑制作用,热害指数高达60.5。与叶面喷施清水对照相比,叶面喷施80 g·hm^(-2) 1-MCP显著提高了高温胁迫下幼苗生物量、根系活力、叶绿素含量、净光合速率和叶片抗氧化酶活性,增加了叶片可溶性蛋白和可溶性糖的含量,有效抑制活性氧积累并降低细胞膜透性,而且显著降低了叶片中脱落酸含量和乙烯释放速率,提高了辣椒坐果率和单果质量。表明叶面喷施适宜浓度的1-MCP可通过提高辣椒光合作用、增强渗透调节活性、抑制活性氧积累、调节激素含量等,缓解高温胁迫对辣椒造成的伤害。

Capsicum annuum L.‘Niuneimu Huangshuai’used as experimental material,the possible mechanism of foliar-spraying 1-methylcyclopropene(1-MCP)alleviating the injury of pepper seedlings under high temperature stress was studied.The results showed that the growth of pepper seedlings was significantly suppressed by high temperature stress,and the heat injury index was reached up to 60.5.The biomass,root activity,chlorophyll content,net photosynthetic rate,leaf antioxidant enzymes activities,the contents of soluble protein and soluble sugar of pepper seedlings were significantly promoted by foliar-spraying 80 g·hm-2 1-MCP compared with the treatment of foliar-spraying water.Moreover,the accumulation of reactive oxygen species and cell membrane permeability of pepper seedlings treated with foliar-spraying 80 g·hm-2 1-MCP under high temperature were significantly decreased compared with the treatment of foliar-spraying water.In addition,the abscisic acid content and ethylene release rate in pepper leaves treated with 1-MCP under high temperature stress was decreased,on the contrary,fruit setting and yield per plant were effectively improved compared with the treatment of foliar-spraying water.In conclusion,the results indicated that foliar-applied suitable concentration of 1-MCP on pepper seedlings under high temperature stress could enhance photosynthesis rate and osmotic adjustment activity,inhibited the accumulation of reactive oxygen species,and regulate the hormone contents,as a result,improved the yield of peppers.