花生种皮蜡质和角质层与黄曲霉侵染和产毒的关系

Wax and Cuticle of Peanut Seed Coat in Relat ion to Infection and Aflatoxin Production by Asperillus flavus

摘要:

黄曲霉侵染花生的研究表明,种皮破损的黄曲霉毒素含量显著高于种皮完整的,种皮对黄曲霉侵染和产毒起着重要的屏障作用。采用氯仿去除种皮蜡质,用KOH或角质酶去除种皮角质层后,种子黄曲霉感染率和黄曲霉毒素含量显著提高。种皮蜡质和角质层同时去除的与种皮破损的黄曲霉感染率和毒素含量差异不显著,表明种皮的抗性成份主要是蜡质和角质层。种皮蜡质含量测定和种皮表面扫描电镜观察表明,蜡质的含量和角质层的厚度与品种的抗性有关。抗性品种种皮蜡质含量显著高于感病品种。种皮蜡质提取物在体外抑菌效果不显著,说明蜡质的抗性作用主要是物理性阻止黄曲霉菌的穿透。

Abstract:

The effects of wax and cuticle of peanut seed coat on reducing the infection and aflatoxin production by Aspergillus flavus were studied. Experiments showed that when the wax on seed coat was removed with chloroform or/and cuticle removed with KOH (or cutinase), fungal infection rate and afiatoxin content in the seeds were significantly increased. Aflatoxin content in seeds with wounded seed coat was higher than that in intact seeds after being inoculated with A. flavus. Scanning electron microscopic observation on seed coat revealed that most of resistant seeds were rough in appearance and had adundant wax deposits on seed surfaces. It is indicated that the wax and cuticle play an important role in preventing fungal penetration.