矿源黄腐酸对甜椒幼苗生长和耐热性的影响

Induction effect of mineral fulvic acid on seedling growth and heat resistance in sweet pepper

以"中椒105"甜椒为材料,采用砂培法,研究不同含量(50、175、500和1750 mg·L-1)矿源黄腐酸(MFA)对甜椒幼苗生长,叶片细胞质膜透性、细胞中O-·2和H2O2含量及抗氧化酶活性的影响,分析高温胁迫下的耐热性.结果表明:适宜含量的MFA可显著促进甜椒幼苗生长,500 mg·L-1MFA处理的株高较无MFA的对照增高12.22%,全株鲜重增加24.90%;在高温胁迫下,适宜含量的MFA可提高超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)等抗氧化酶的活性,500 mg·L-1MFA处理的CAT、POD和SOD活性较对照分别提高74.49%、122.08%和16.27%;MFA处理下,通过抗氧化酶对O-·2和H2O2的清除作用,抑制细胞中H2O2和O-·2的积累,从而减轻H2O2对细胞质膜的伤害,降低相对电导率和丙二醛(MDA)含量,维护细胞正常的代谢功能,维持在高温逆境下的正常生长.可见,MFA对提高甜椒幼苗的耐热性有一定的作用,且适宜的使用量为175-500 mg·L-1.

Sandy culture method was conducted to examine the effects of mineral fulvic acid （MFA） on the seedling growth,lipid peroxidation,electrolyte leakage,reactive oxygen species and antioxidant enzyme activities,such as catalase （CAT）,superoxide dismutase （SOD） and peroxidase （POD）,in sweet pepper （Capsicum tetragonum） seedlings under heat stress.The growth of seedlings were hastened by MFA obviously.The growth of the seedling irrigated with 500 mg· L-1 MFA was promoted by 12.22% （height） or 24.90% （weight）.The efficiency of H2O2 eliminating was increased,and the concentration of malondialdehyde （MDA） was reduced.As a result,the harm of the membrane was mitigated.The activities of antioxidant enzymes such as SOD,CAT and POD in the leaves of the seedling irrigated with 500 mg· L-1 MFA were increased by 74.49%,122.08% and 16.27% separately.It was confirmed that MFA could induce the heat resistance of sweet pepper seedlings and the effeetive concentration was intervenient between 175 mg · L-1 and 500 mg · L-1.