Bacterial panicle blight (BPB), incited by Burkholderia glumae, has impacted rice production globally. Despite its significance, little is known about the disease and the virulence pattern of the causal agent. BPB is a major challenge in the rice‐growing belts of North‐western India. We have characterized the 21 BG strains using the 16S rRNA and the gyrB gene‐based sequence approach in the present study. The gyrB gene‐based phylogenetic analysis resulted in geographic region‐specific clustering of the BG isolates into three clades. The BG isolates from Delhi‐National Capital Region (Delhi NCR) (Clade 1) and Uttar Pradesh (UP) (Clade 2) were separated into two clades and the BG isolates from Uttarakhand and Haryana clustered together in a single clade (Clade 3). Likewise, we sequenced the eight major virulence‐associated genes viz., toxA, toxB, lipA, lipB, pehA, pehB, flhC and flhD present across the genome of B. glumae and identified their interacting proteins through STRING analysis. Furthermore, virulence screening of 21 BG strains revealed the variation in the percentage of grains infected and the yield of rice plants. The most virulent BG1 strain resulted in the highest disease incidence (82.11%) and lowest yield (11.12 g/plant) and BG10 came out as the least virulent strain. Besides, the inoculation at three stages of the plant revealed that the booting stage of rice is the most susceptible stage which resulted in maximum disease percentage and less yield. Overall, our study gives information about virulence‐associated gene characterization and variation in the virulence nature of Indian BG strains.

中文翻译：

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导致水稻穗枯病的新出现的印度颖枯病菌菌株的毒力分析

细菌性穗枯病（BPB），由以下因素引起荚膜伯克霍尔德氏菌，影响了全球水稻生产。尽管其意义重大，但人们对这种疾病和致病因子的毒力模式知之甚少。 BPB 是印度西北部水稻种植带的一个重大挑战。在本研究中，我们使用 16S rRNA 和基于 gyrB 基因的序列方法对 21 种 BG 菌株进行了表征。这吉尔B基于基因的系统发育分析将 BG 分离株按地理区域特异性聚类为三个分支。来自德里国家首都地区 (Delhi NCR)（进化枝 1）和北方邦 (UP)（进化枝 2）的 BG 分离株被分成两个进化枝，来自北阿坎德邦和哈里亚纳邦的 BG 分离株聚集在一个进化枝（进化枝 3）中。同样，我们对八个主要毒力相关基因进行了测序，即，毒素A,毒物B,脂A,唇B,佩赫A,佩赫B,FLHC和FLHD存在于整个基因组中颖壳芽孢杆菌并通过 STRING 分析确定了它们的相互作用蛋白。此外，对 21 个 BG 菌株的毒力筛选揭示了受感染的谷物百分比和水稻产量的差异。毒性最强的 BG1 菌株导致发病率最高（82.11%）和最低产量（11.12 克/株），而 BG10 是毒性最小的菌株。另外，对水稻三个时期的接种结果表明，水稻孕穗期是最易感病的时期，发病率最高，产量也较低。总体而言，我们的研究提供了有关印度 BG 菌株毒力相关基因特征和毒力性质变化的信息。