禾谷镰刀菌武昌菌株毒素的毒性分析

为提高小麦抗赤霉病体细胞的筛选效果，对禾谷镰刀菌武昌菌株的产毒、毒素提取、纯化、毒素组分及毒素初定量进行了研究。麦粒培养基培养２５天后可检测到两个主要毒性组分（Ａ和Ｂ）。其特征吸收峰值分别为２７０和２７５ｎｍ，Ｒｆ值分别为０．４５和０．５５左右。ＳＰＭ培养基培养只能检测到组分Ａ。Ａ组分与脱氧雪腐镰刀菌烯醇（ＤＯＮ）的结构特征基本相同。经高压灭菌的毒素可渗入到培养基中作抗性愈伤组织的筛选剂。毒素对愈

TOXICITY ANALYSIS OF THE TOXINS PRODUCED BY THE WUCHANG STRAIN OF FUNGI (GIBBERELLA ZEAE)

The culture,extraction,purification,components and content of toxions produced by the Wuchang strain of fungi(gibberella zeae)were studied.There are two water-soluble components in the toxins produced by the tested fungal strains during culturing on the wheat seeds.The critical time for efficient toxin producing occurs at 25 days of culture.Only one component,which resembled DON in structure,was detected in SPM shaking culture.The toxins remained capable of permeating the medium when sterilized,and thus can be used as selectors for resistant callus.The effects of toxins on callus are as follows:(a)lethality,(b)obvious inhibition to the growth of callus,(c)reduction in the number of greens growth of callus,(c)reduction in the number of greens pots of callus ,and(d)other consequent effects on the growth of callus.In addition,there are obvious distinctions in size and growth speed among different calli.Various concentrations of toxins should be used with respect to different varieties.The PAL enzyme activity level can be used as a criterion for identifying resistant lines.