花生种子及制品极易受黄曲霉菌侵染。利用不同的抗病种质为材料,对黄曲霉菌侵染抗性的持久性以及种皮完整性对产毒的影响进行了研究。结果表明,在常温条件下,抗黄曲霉侵染的花生种子至少可以安全贮藏7个月,其与新鲜种子受黄曲霉菌侵染后的发病率和发病指数差异不显著。但是,贮藏9个月的花生种子其抗病能力明显降低。完整种皮对黄曲霉菌产毒能力的影响在抗侵染与感病种质之间存在较大差异。对于抗黄曲霉侵染种质,受黄曲霉菌侵染后,具备完整种皮的种子比破损种皮种子的毒素含量低;对于感病种质,受黄曲霉菌侵染后,具备完整种皮的种子比破损种皮种子的毒素含量高。有关成分分析表明,高含油量、高蛋白质含量和高油酸资源对黄曲霉菌侵染和产毒的抗性较差。相关分析表明,不同花生品种对黄曲霉菌的侵染抗性与油酸含量呈显著负相关,与亚油酸含量呈显著正相关;不同花生品种对黄曲霉菌产毒的抗性与含油量呈显著负相关。通过鉴定和筛选,发掘出2份优质抗病资源G845和G8。
Peanut and its products are generally susceptible to Aspergillus flavus and contaminated consequently aflatoxin under both preharvest and postharvest conditions. In China, both preharvest infection because of end-of-season drought and postharvest infection because of humid and high temperature environment and poor storage condition were severe. Utilization of genetic resistance is one of the most efficient approaches for the control of aflatoxin. Durability of resistance to Aspergillus flavus infection in storage is one of important resistant components in peanut. Up to now, several genotypes with aflatoxin resistance have been identified but not been efficiently used in breeding program because of poor agronomic and chemical characters. In the present study, peanut genotypes with diverse reaction to infection of Aspergillus flavus were used to investigate the persistence of resistance in seed storage and the impact of intact testa on aflatoxin contamination. The results indicated that the resistance to Aspergillus flavus could be lasted for at least seven months in resistant germplasms under conventional storage conditions in central China after harvest. No significant difference between the seed samples stored for seven months and freshly harvested one in terms of invasion ratio and infection index. However, the resistance could be declined or lost after nine-month storage. The quick decline of the resistance was due to the change of temperature. The impact of intact testa on aflatoxin production under artificial inoculation was different between the resistant and susceptible genotypes. The aflatoxin content in samples with intact testa was lower in resistant genotypes but higher in susceptible genotypes than that with damaged testa. Peanut genotypes with high oil, protein and oleic acid were generally more susceptible to Aspergillus flavus invasion. The infection by Aspergillus flavus was significantly negative correlated with oleic acid content and significantly positive correlated with linolenic acid content. And the aflatoxin contamination content by Aspergillus flavus are significantly negative correlated with oleic acid content. Two genotypes with resistance and good seed quality, G845 and G8 had been identified.
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