柳树干锈病的研究

A Study on the Stem Rust of Willow

柳树干锈病（Ｕｒｅｄｏｓｐ．），主要危害柳树枝干韧皮部，亦危害叶、叶柄和花序等部位。病菌以双核菌丝在枝、干的韧皮部老病斑周围活组织内越冬，４月下旬至１２月产生夏孢子堆，夏孢子可重复侵染叶、叶柄和嫩梢，５月下旬至８月下旬为发病盛期。４月下旬至５月上旬在枝干老病斑周围皮下产生夏孢子，作为初次侵染来源，经风传播，由自然孔口或直接入侵，潜育期７～１８ｄ。病害为局部侵染，局部发病。夏孢子萌发的适温为２０～２４℃。人工接种叶片和嫩梢后，可产生夏孢子堆。绦柳、垂柳、旱柳、川滇柳、龙爪柳和左旋柳等均可染病。

The stem rust of willow (Ured sp.) in a kind of serious disease discovered newly,which occurs in Gansu,Ningxia,Qinghai,Tibet and Shandong.It mainly invaded phloem of trunk,leaf,stipe and inflorescence.The dicaryotic surrounding old disease pathched in phloem of the branch and stem of willow. Uredinia produced from late April to December.They could reinfect leaves,stipes and tender shoots. Flourish period of the disease occurred from late May to late August.From late April to early May urediospore formed beneath bark around the old disease pathches.Urdeiospore were spreaded by wind,penetraded directly or through natural holes. Incubation period was 7 to 18 days. The disease patch usually occurred around the point of infection. Optimum temperature for germination of urediospore was 20-24℃,Uredinia could produce when urediospore was inoculated. Salix matusudana Koidz.var. pendula Schneid, S. babylonica Linn. S.matsudana Koidz, S. rehderana Schneid, S.paraplesia var. subintegra C.Wang et P.Y.Fu could be infected and S.mastsudana Koidz.var. pendula Schneid showed to be the most suscepible.