VIRULENCE AND CULTURAL-CHARACTERISTICS OF 2 ASPERGILLUS-FLAVUS STRAINS PATHOGENIC ON COTTON
VIRULENCE AND CULTURAL-CHARACTERISTICS OF 2 ASPERGILLUS-FLAVUS STRAINS PATHOGENIC ON COTTON
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DOI：
10.1094/phyto-79-808
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发表时间：
1989-07-01
期刊：
影响因子：
3.2
通讯作者：
COTTY, PJ
中科院分区：
文献类型：
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作者：
COTTY, PJ
根据菌核大小、培养特性和对棉花的毒力，将来自亚利桑那州沙漠山谷的70株黄曲霉菌株分为两个不同的菌株。菌株L分离物产生大菌核（直径超过400 μ m），菌株S分离物产生小菌核（直径小于400 μ m）。菌株S分离物产生更大量的菌核在更广泛的品种的媒体和更广泛的温度范围比菌株L分离物。这两种菌株的分离株在培养中表现出pH稳态。然而，菌株保持不同的pH值。菌株S分离株产生更多的黄曲霉毒素比菌株L分离株在文化中，但是，菌株产生类似的黄曲霉毒素水平在发展中的棉籽。菌株L菌株比菌株S菌株在恶化棉铃锁（小室）和棉铃内传播更具侵略性，这种趋势部分解释了黄曲霉毒素的体外和体内生产之间的差异。受侵染种子中的黄曲霉毒素含量与离体黄曲霉毒素含量、铃内真菌传播和铃壳劣变均不相关，但与离体黄曲霉毒素含量和铃内真菌传播参数的乘积相关（r = 0.75-0.91）。当将锁退化因素纳入方程时，相关性略有增加（r = 0.78-0.93）。这些结果表明，致病性的侵略性有助于分离物的能力，污染棉籽黄曲霉毒素。致病性侵略和体内黄曲霉毒素产生之间缺乏相关性，表明黄曲霉毒素不会增强棉A的毒力。黄交互作用
Seventy Aspergillus flavus isolates from Arizona desert valleys were sorted into two distinct strains on the basis of sclerotial size, cultural characteristics, and virulence to cotton. Strain L isolates produced large sclerotia (over 400 .mu.m in diameter), and strain S isolates produced small sclerotia (less than 400 .mu.m in diameter). Strain S isolates produced greater quantities of sclerotia in a wider assortment of media and a broader temperature range than strain L isolates. Isolates of both strains exhibited pH homeostasis in culture. However, the strains maintained different pH values. Strain S isolates produced more aflatoxin than strain L isolates in culture; however, the strains produced similar aflatoxin levels in developing cottonseed. Strain L isolates were more aggressive than strain S isolates at deteriorating cotton boll locks (locules) and spreading within bolls, and this tendency partly explains the difference between in vitro and in vivo production of aflatoxin. The aflatoxin level in infected seeds was not correlated with either the aflatoxin level in vitro, intraboll fungal spread, or lock deterioration, but it was correlated with the product of the aflatoxin level in vitro and the intraboll spread parameter (r = 0.75-0.91). The correlation increased slightly (r = 0.78-0.93) when lock deterioration was factored into the equation. These results indicate that pathogenic aggressiveness contributes to the ability of an isolate to contaminate cottonseed with aflatoxins. The lack of correlation between pathogenic aggression and aflatoxin production in vivo suggests aflatoxin does not enhance virulence in the cotton-A. flavus interaction.