小麦的腥黑穗病主要发生在穗部。病株一般较健壮株稍矮，分蘖增多，病穗短直，颜色较健壮穗深，初为灰绿色，后变灰黄色。病粒较健粒短而胖，因而颖片略开裂。露出部分的病粒初为暗绿色，后变灰黑色，如用手指微压，则易破裂，内有黑色粉末。病粒因含有挥发性三甲胺，有鱼腥味 Toxicity of wheat mainly occurs in the ears. The diseased plants are generally slightly shorter than the robust plants, with increased tillers, short panicles of the diseased ear, and darker color than the healthy ones. The first is gray-green and the second is yellowish-gray. Shots are shorter and fatter than shots, and therefore cracked slightly. Part of the exposed part of the grain is dark green at the beginning, after turning gray, such as micro-pressure with your fingers, then easy to rupture, there are black powder. Granules contain volatile trimethylamine, a fishy smell