大豆细菌性斑疹病的病原鉴定及大豆新种质抗性评价

Identification of Pathogen Causing Bacterial Pustule Spot of Soybean and Resistance Evaluation of New Soybean Germplasm

通过对一种近年在江苏省南京市发生严重的大豆叶部病害的病原物进行分离鉴定,检测和评价了本地区大豆新育成品种系及亲本对该病害两个菌株的抗病性。结果表明:通过病原物分离和回接大豆,确定了4株细菌是引起该病害的病原物。形态学观察、生理生化测定、以及16S r DNA和gyr B聚类分析表明这4株菌株属于地毯黄单胞菌大豆致病变种(Xanthomonas axonopodis pv.glycines)。233份大豆新种质对强致病性菌株C5和B523的抗病性检测结果表明,其对两个菌株的抗性反应存在差异,对C5和B523具有抗病性(高度抗病+中度抗病)的种质分别只占鉴定材料的40.35%和37.77%,说明本地品种总体抗性水平并不高,病害具备流行的前提条件;只有苏鲜21和徐豆16对两个菌株均表现高抗,是抗病育种的优良亲本。

In this study,the pathogen which caused the serious disease of soybean leaves in Jiangsu province was isolated and identified,and a set of newly developed varieties,breeding lines and parents were used to evaluate the disease resistance to the pathogen. The results showed that four strains,which were isolated from different soybean leaf samples could result in the same symptom,were identified as the pathogen. Then,through morphology,biochemical and physiological identification,and16 S r DNA and gyr B cluster analysis,those 4 strains were further classed as the Xanthomonas axonopodis pv. glycines. Different resistance reactions of soybean germplasm to C5 and B523 pathogen strains could be observed. The ratios of soybean accessions with resistance to C5 and B523 were only 40. 35% and 37. 77%,respectively. It indicated that the resistance level of these soybean lines was not high,and there was precondition for widespreading of the disease. Among the 233 tested accessions,two soybean varieties,Suxian 21 and Xudou 16,showed high resistance to the two strains,and could be used for developing disease-resistant varieties.