云杉叶疫病的研究

STUDIES ON THE NEEDLE BLIGHT OF SPRUCE

本文报道了在我国新发现的一种病害,云杉叶疫病。在国外许多其他地区,这是一种广泛分布的病害,英国、欧洲、北美洲及日本均有报道。这一病害也发生在我国云南省西北部和四川省西部的丽江云彩及其变种上,是由一种根球壳孢菌(Rhizosphaera kalkhoffia Bubak)所引起。每年春末夏初,染病针叶表现褪绿,然后转呈紫褐色、枯死,于秋季脱落。病原茵在染病针叶上产生小形、黑色、有柄的分生孢子器,从气孔伸出表面,排列成行。分生孢子器内含有椭圆形至卵形、无色、单细胞的分生孢子。严重感病的观赏树木可在春季喷撒波尔多液数次,能取得良好防治效果。

The needle blight disease of spruce,which is new to china,is described in this paper.It is a common and widespread disease recorded in Europe,North America and Japan.This disease occurs on Picea likiangensis(Fr.)Pritz. and its varieties in Northwestern Yunnan and Western Sichuan.It is caused by Rhizosphaera kalkhoffia Bubak,In late spring,the affected needles become discolored and then purple-brown,and eventually result in the death and cast during the fall,On the affected needles,small,black,stalked pycnidia are formed over stomata in regular rows.The pycnidia contain elliptic or ovoid one-celled spores.This disease may be controlled successfully on ornamental trees by spraying with Bordeaux mixture several times in spring.