黄瓜绿粉病病原鉴定及其发生规律研究

黄瓜绿粉病是温棚蔬菜上一种新病害,由绿藻门集球藻(Palmellococcus sp.)引起。藻孢卵圆形、长椭圆形、淡绿色、单胞、大小3.39～12.38μm×1.06～10.82μm,表面有山脊状隆起,是一种依附于体表的气生性自养生物。该病害多在1～3月份发生,与湿度密切相关。每日温棚中RH不低于80%,RH100%在12h以上,藻孢生长旺盛;当中午有1h以上RH低于70%时,藻孢的发育受到抑制。凡能增大温棚湿度的栽培措施如灌水、密植等因素均能加重发病。黄瓜品种抗病性无明显差异。

Identification of the green powdery pathogentotic fungi on cucumber infected by Planellococeus sp. and the occurrence of disease

Green powdery of cucumber is a new disease caused by Planellococeus sp. of Chlorophyta in solar energy greenhouse. The frond is an oval shaped or long ellipsoid, lightgreen single cell with size 3.39-12.38 μm×1.06-10.82 μm, and ridge shaped erections on its surface. It is epiphyllous aerial autotrophes. The disease occurs only in January-March. every year,and is closely related with RH It develops prosperously when RH is not lower than 80% and 100% RH remains 12 h daily in the green house, while its development is suppressed if 100% RH remains less than 12 h daily and RH is lower than 70% lasting more than 1 h at noon. Cultural practices, such as watering and dense planting, can worsen the disease.