Nematodes (Meloidogyne spp.) are a major reason behind the global crop yield reduction. The bacterial strain KMT-4 was isolated from nematode-affected tomato (Solanum lycopersicum) rhizosphere at research farms, Hisar, India, and screened for its biocontrol potential against root-knot nematode Meloidogyne javanica as well as checked for its effect on plant growth and yield. The bacterium KMT-4 was identified as Bacillus aryabhattai based on phenotypic characters and 16S rRNA sequence analysis. During in vitro studies, hatching and mortality of M. javanica were significantly affected due to the antagonistic behavior exhibited by the bacterium. In addition to this, KMT-4 also displayed various direct as well as indirect plant growth-promoting attributes like siderophore production, growth hormone (IAA) production, ammonia excretion, hydrogen cyanide production, and chitinase activity. A pot house experiment conducted on brinjal resulted in nearly 73% reduction in eggs, while 80% reduction in galls in the plant root compared to the untreated and chemically treated plants. The final nematode population also reduced significantly in KMT-4 treatment. It was 1141.6 J2/200cc soil in control and reduced to 108 J2/200 cc soil inoculated with KMT-4. Similar results were obtained in field experiments on brinjal and cucumber conducted in years 2018 and 2019, respectively. Also, a notable enhancement in the plant growth was observed in both pot house experiment and field trials. The possession of nematicidal activity along with plant growth-promoting properties in B. aryabhattai KMT-4 warrants its employment as a potent biological control agent against M. javanica and a promising substitute of chemical nematicides.

中文翻译：

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关于芽孢杆菌KMT-4对爪哇根结线虫的潜力

线虫（Meloidogyne spp。）是全球农作物减产的主要原因。细菌菌株KMT-4是在印度希萨尔的研究农场从线虫感染的番茄（Solanum lycopersicum）根际中分离出来的，筛选了其对根结线虫Meloidogyne javanica的生防潜力，并检查了其对植物生长和生长的影响。屈服。根据表型特征和16S rRNA序列分析，细菌KMT-4被鉴定为芽孢杆菌。在体外研究中，由于细菌表现出的拮抗作用，爪哇分枝杆菌的孵化和死亡率受到了显着影响。除此之外，KMT-4还显示了各种直接和间接促进植物生长的特性，例如铁载体的产生，生长激素（IAA）的产生，氨的排泄，氰化氢的产生，和几丁质酶的活性。与未处理和化学处理过的植物相比，在茄子上进行的盆栽试验使鸡蛋减少了近73％，而在植物根部的胆汁减少了80％。在KMT-4处理中，最终的线虫种群也显着减少。对照为1141.6 J2 / 200 cc土壤，并减少为108 J2 / 200 cc KMT-4接种土壤。在分别于2018年和2019年对茄子和黄瓜进行的田间试验中获得了类似的结果。另外，在温室试验和田间试验中均观察到植物生长显着增强。B. aryabhattai KMT-4具有杀线虫活性以及促进植物生长的特性，因此有必要将其用作对抗M的有效生物防治剂。