云南高原粳稻区白叶枯病菌致病型鉴定及主栽品种抗性反应初析

A Preliminary Analysis of Pathotypes of Xanthomonas oryzae pv. oryzae and the Resistant Reactions of Main Japonica Rices in the Yunnan Plateau

从云南高原粳稻区采集分离36份白叶枯病菌株,在包括初步选定的7个高原粳稻白叶枯病菌鉴别品种(毫糯扬、TN1、黄玉、珍珠矮、IR26、南粳33、金南风)在内的29个水稻品种上测定致病型,进一步明确了这7个鉴别品种的有效性。发现菌株与品种之间具有交叉互作反应,菌株与品种之间存在质的特异性互作关系;利用这套鉴别品种可将36个菌株划分为9个致病型,其中Ⅴ型菌为优势菌群,Ⅶ型菌为毒性菌群。云南高原粳稻区的主栽品种多数感病。稻种资源IRBB21(Xa-21)、扎昌龙(Xa-22t,Xa-24t)、IR1545-339(xa-5)对所有参试菌株均表现抗病,在云南高原粳稻育种中具有较好的利用价值。

The pathogenicity of 36 isolates of Xanthomonas oryzae pv. oryzae (Xoo), which were collected from japonica rices in the Yunnan Plateau, was evaluated on 29 rice varieties including a set of 7 varieties to identify pathogenicity, ie. Haonuoyang, TN1, Kogyoku , Zhengzhuai, IR26, Nanjing 33 and Kinmaze, which may be considered as a set of differential varieties for Xoo races from Yunnan japonica rice. The efficiency of the 7 varieties was further confirmed. The results showed reversible and specific reactions between isolates and varieties. The isolates were classified into 9 pathotypes from pathotype I to Ⅸ according to their pathogenic reactions on the 7 rice varieties. The pathotype Ⅴ was the epidemic while pathogen Ⅶ was the most pathogenic. Most japonica varieties being grown in the Yunnan plateau were susceptible to Xoo. The rice lines IRBB21 (Xa-21), Zhachanglong (Xa-22t,Xa-24t)and IR1545-339 (xa-5), which were resistant to all the isolates tested, can be used as donors of resistant genes for bacterial blight in japonica rice breeding in the Yunnan Plateau.