四川地区小麦条锈病大流行特点及原因分析

FEATURES OF THE EPIDEMIC OF WHEAT STRIPE RUST IN 2002 IN SICHUAN AND THE CAUSES UNDERLYING IT

2 0 0 2年小麦条锈病在四川大流行 ,发生面积、病情指数、实际损失等各项指标均高于历史最高水平。四川省既是条锈病的越夏区 ,又是重要的越冬区 ,也是春季流行区 ,大区流行有自身独有的特点 :一是越夏区菌源充足 ,越冬区扩展迅速 ;二是病菌沿 4大河流流域 (涪江流域、沱江流域、岷江流域和嘉陵江流域 )自北向南扩展 ;三是越冬区和非越冬区损失并重。小麦条锈病的发生呈现以下 5个特点 :一是秋苗发病早 ,病菌侵染时间长 ;二是来势猛 ,波及面宽 ;三是非常发区为害加重 ;四是病情严重 ,危害损失大 ;五是所有推广品种均发病。 2 0 0 2年小麦条锈病的发生流行呈现上述特点 ,究其原因有 :一是菌源充足 ;二是品种抗性严重丧失 ;三是适宜的气候条件 ;四是一些地方防治水平不高。

Unprecedented epidemic of stripe rust of wheat (Puccinia striiformis Weat.) occurred in Sichuan in 2002. The acreage of affected fields, disease index and economic losses broke any historical records. Sichuan is a region of over-wintering and over-summering for the pathogen and also a region for its spring epidemic. The present study summarizes three features for the spreading of the disease in the province: (a) sufficient sources of the inoculum over the summer and the rapid development of the disease over large areas; (b) the inocula extended from north to south along the four major river valleys: the Fujiang River, the Tuijiang River, the Minjiang River and the Jialingjiang River; (c) both the over-wintering and non-over-wintering regions suffered from the disease. It is presumed that the great epidemic of Puccinia striiformis Weat. in 2002 in Sichuan is attributed to (a) sufficient source of the pathogen, (b) the loss of disease resistance of the resistant varieties, (c) climatic conditions favorable for the development of the pathogen and (d) inadequate disease control measures in some regions.