摘要： 为明确西南地区水稻籼、粳分化对白叶枯病菌群体结构特征的影响,掌握病菌毒性变异以及致病型在籼稻和粳稻上的分布规律,为水稻品种抗性基因选育和抗性品种推广提供有效策略。利用6个含有单抗基因的近等基因系材料为鉴别品种,对西南地区不同水稻品种的218个菌株致病型进行测定。结果显示:西南稻区白叶枯病菌致病型具有丰富的多样性,共包含18种致病型;籼稻和粳稻上病菌致病型组成存在明显差异,粳稻上病菌致病型数量较多,籼稻较少;粳稻上病菌致病型丰富度指数、多样性指数和均匀度指数均高于籼稻;通过分析病菌对抗性基因的克服数量以及鉴别品种病斑长度,结果显示,籼稻上病菌的毒力显著高于粳稻;以彼此间相似率60%为界聚类分析病菌致病型,18种致病型可归为4个聚类簇,其中簇Ⅰ中菌株毒性最弱,来自粳稻上的病菌有42%集中在这个聚类簇中,而来自籼稻上的病菌75%集中在毒性最强的簇Ⅳ中。因此,就品种的布局而言,在病菌毒性较强的籼稻区应尽可能使用含有多个抗性基因的聚合品种,避免单一品种的长期种植,防止病害的大规模流行。鉴于粳稻区病菌毒性弱、毒谱窄,育种部门应与监测部门联合,制定好抗性基因轮换的宏观计划,并且加强籼稻区稻种外运时的检疫工作,防止强毒性菌株随种子的携带而传播。
关键词:
水稻白叶枯病,
毒力,
籼稻,
粳稻,
抗性基因,
致病型-多度分析
Abstract: To study the population structures of Xanthomonas oryzae pv.oryzae and understand the virulence variation and pathotypic diversity of pathogen in indica and japonica rice in Southwest China,218 strains were tested using 6 near-isogenic rice lines each containing a single resistance gene to provide effective strategies on breeding resistance genes and resistant varieties application.Our main results were as following The tested strains were diversified and it includes 18 pathotypes;The population structures of Xanthomonas oryzae pv.oryzae in different cultivar types were distinction.The number of pathotypes of Xoo in japonica rice was more than those in indica rice.Richness index,Shannon index and evenness index kept at low level in indica rice and showed significant differences between strains isolated from japionica and indica rice.We found the virulence of strains in different cultivar types were very different when we analyzed the number of resistance genes defeated and the average lesion length of rice lines infected by strains.The virulence of strains isolated from indica rice were higher than those from japonica rice.All strains tested were similar to each other at a level of 60% similarity,18 pathotypes of strains were constituted four clusters.Strains belonging to clustersⅠwith weak virulence were mainly isolated from japonica rice,while strains of cluster Ⅳ with strong virulence were mainly isolated from indica rice.As far as the layout of the breed is concerned,the rice cultivar containing more resistance genes should be used in indica rice planted region,while a programme of alternating genes for forestalling the pathogen variation should be worked out in japonica rice planted region for the purpose of disease reduction.
Key words:
Bacterial blight,
Virulence,
Indica rice,
Japonica rice,
Resistance gene,
Pathotype-abundance analysis
中图分类号:
陈小龙, 余磊, 高玲玲, 孙跃先, 黄琼. 西南地区水稻籼粳分化对白叶枯病菌毒性变异的影响[J]. 华北农学报, 2012, 27(5): 168-173. doi: 10.3969/j.issn.1000-7091.2012.05.032.
CHEN Xiao-long, YU Lei, GAO Ling-ling, SUN Yue-xian, HUANG Qiong. Effect of Indica-japonica Differentiation on Virulence Variation of Xanthomonas oryzae pv. Oryzae[J]. ACTA AGRICULTURAE BOREALI-SINICA, 2012, 27(5): 168-173. doi: 10.3969/j.issn.1000-7091.2012.05.032.