Studies On The Resistance Identification And Mechanism Of Peanut Varieties (Arachis Hypogaea Linn.) To Aspergillus Flavus

Peanut, as an important oil and economic crop, is also one of the few internationally competitiveexport crops. Its seeds contain50%oil,30%protein and eight essential amino acids necessary for ourbody and so on, whose nutritional value is comparable to that in animal foods such as eggs,dairy and meat..However, it is vulnerable to aflatoxin, a strong carcinogen. Aflatoxin contamination, as one of the majorissues of the quality of peanuts and food safety, has severely threatened the health of human beings anddrawn widespread attention in the world. Breeding anti-aflatoxin varieties is the most effective, economicand safest solution to solving the Aflatoxin contamination,while determining the resistance mechanism ofAspergillus flavus-resistant varieties is the premise of breeding Aspergillus flavus-resistant varieties. Inthis study, the resistance identification and mechanism of peanut varieties(arachis hypogaea linn.)toaspergillus flavus were studied.The main findings are as follows:1. Aspergillus flavus strains were separated from soil and moldy peanuts and identified according tothe morphological features and colony color of its strains and the morphological features of Conidia.2.The resistance of20peanut varieties to A. flavus infection was determined by A. flavus artificialinoculation.The results showed that the varieties resistant to A. flavus are Zhonghua No.6and anti-aflatoxinNo.1, accounting for10%of tested varieties; moderate resistance varieties are Kainong No.37, KainongNo.41, Yuhua No.4, White Peanut and Kainong No.3,25of the tested vultivars; varieties vulnerable toaflatoxin are Yuhua No.7, Zhouhua No.2, Xinhua No.1, Puhua No.17, Baisha No.4and Honghua350,30%of the tested cultivars; high susceptible varieties are W9813,W9742,W9846,Yuhua No.6,Gz414,Gz392and Gz427,35%of the tested cultivars. Varieties susceptible to Aspergillus flavus account for65%. Thereis no significant correlation between the resistance of peanut seed kernels and that of peanut pods toAspergillus flavus. Peanut AFLP analysis indicated that there are some differences in the resistance toAspergillus flavus among different peanut varieties, but resistance, moderate resistance, moderate infectionand high infection peanut varieties can not be accurately identified.3. There are significant changes in the activities of peroxidase, catalase, polyphenol oxidase andPhenylalanine ammonia-lyase in peanut seeds of Aspergilus flavus-resistant and sensitive varieties infectedby Aspergilus flavus strains. According to the change trends of enzyme activity, the time when the activity reached the peak, and their relations with the resistance to Aspergilus flavus, resistant and sensitivevarieties can be clearly identified.Aspergillus flavus-resistant peanut varieties identified above will provide parental samples for peanutAspergillus flavus resistance breeding.The relationship between enzyme activities and Aspergillusflavus-resistance revealed by the study will provide the theoretical basis for peanut Aspergillusflavus-resistance breeding and Anti-disease gene engineering breeding.