紫花苜蓿白粉病病原鉴定

Identification of pathogen on Alfalfa powdery mildew

通过对甘肃定西县一年生紫花苜蓿白粉病蜡叶标本上的白粉菌的显微观察和计测,该菌闭囊壳直径85.5～128.3 m,平均直径95.7 m。每个子囊壳附属丝平均数量为27条,多数为20～30条。每个子囊壳含子囊6～8个,多数为6个,子囊大小为85.5m32.1 m。子囊内有子囊孢子2～4个,绝大多数为2个。167个子囊孢子计测结果,大小为32.1～21.4 m。附属丝褐色,多数基生,少数侧生,菌丝状,长度为子囊壳直径的0.6～1.6倍。经鉴定苜蓿上的白粉菌为蓼白粉菌(Erysiphe polygoni DC.)

Studied on morphology of the causal agent of powdery mildew of Alfalfa from the herbaria specimen obtained Dingxi, China. The average diameter of 105 cleistothecia collected was 97.5 靘. The range was 85.5～128.3 靘. The average number of appendages was 27 per cleistothecium. Clastothecia contained five to eight , most commonly six asci. Asci averaging 32.1靘?5.5 靘 with a range of 21.4~42.8?4.1～106.2 靘 for the 97 asci measured The number of ascospores per ascus varied from two to four , and average dimensions of 167 ascospores were 10.7?2.1 靘 with a range of 10.7～20.4靘?1.4～42.8 靘. Appendages were hyaline, basal and a few lateral , straight to slightly cured with the mycelium , and half to one and half times as long as the diameter of the cleistothecium. This was just only Erysiphe polygoni DC.