Sclerotium rolfsii is a soil-borne fungal pathogen causing diseases in more than 500 plant species. It causes southern blight disease in chili. Chemical fungicides are used to control this disease, which also pollute the environment. The present study was designed to assess the potential of two species of plant-growth-promoting rhizobacteria (PGPR) viz. Bacillus megaterium and Pseudomonas fluorescence, and an allelopathic weed, Anagallis arvensis L., for the control of southern blight disease of chili. Initially, three PGPR strains, viz. B. megaterium OSR3, B. megaterium ZMR6, and P. fluorescence PF-097, were selected for their in vitro antagonistic assessment against S. rolfsii by dual culture technique on potato dextrose agar medium. OSR3 showed the highest antagonistic potential (68%), followed by PF-097 (54%) and ZMR6 (33%). In a pot experiment, the two best strains of PGPR, namely OSR3 and PF-097, and dried biomass of A. arvensis (DBA) in different concentrations (1, 2 and 3%) were used to manage southern blight disease of chili. In positive control treatment (S. rolfsii only), plant survival was low (73%) than the negative control (100%). OSR3, PF-097, OSR3 + 2% DBA, and PF-097 + 2% DBA significantly enhanced plant survival over positive control. The highest increase in chili growth over positive control was recorded due to OSR3, followed by PF-097 inoculations. Contents of carotenoid and chlorophyll were significantly decreased due to the fungal pathogen and improved due to PGPR strains. Application of the two PGPR strains and different concentrations of A. arvensis distinctly increased the catalase (CAT), peroxidase (POX), and polyphenol peroxidase (PPO) activities over positive control. The present study concluded that PGPR strains B. megaterium OSR3 and P. fluorescence PF-097 can control southern blight disease effectively and increase growth and yield of chili.

中文翻译：

---

促进植物生长的根际细菌和Anagallis arvensis诱导辣椒对Rolfsii的抗性

菌核菌是土壤传播的真菌病原体，在500多种植物中引起疾病​​。它在辣椒中引起南方疫病。化学杀真菌剂用于控制这种疾病，这种疾病也污染环境。本研究旨在评估两种植物促生根瘤菌（PGPR）的潜力。巨大芽孢杆菌和假单胞菌荧光，以及化感杂草Anagallis arvensis L.，用于控制辣椒的南部疫病。最初，三个PGPR菌株，即。通过马铃薯右旋糖琼脂培养基上的双重培养技术，选择了巨大芽孢杆菌OSR3，巨大芽孢杆菌ZMR6和荧光毕赤酵母PF-097进行体外拮抗。OSR3表现出最高的拮抗潜力（68％），其次是PF-097（54％）和ZMR6（33％）。在盆栽试验中，使用两种最佳的PGPR菌株OSR3和PF-097，以及不同浓度（分别为1、2和3％）的干曲霉生物量（DBA）处理辣椒的南部疫病。在阳性对照处理（仅S. rolfsii）中，植物存活率（73％）低于阴性对照（100％）。与阳性对照相比，OSR3，PF-097，OSR3 + 2％DBA和PF-097 + 2％DBA显着提高了植物的存活率。由于OSR3，随后是PF-097接种，导致辣椒生长超过阳性对照的最高记录。由于真菌病原体，类胡萝卜素和叶绿素的含量显着降低，而由于PGPR菌株，其含量有所提高。两种PGPR菌株和不同浓度的A. arvensis的应用明显增加了过氧化氢酶（CAT），过氧化物酶（POX），和多酚过氧化物酶（PPO）活性高于阳性对照。本研究的结论是，PGPR菌株B. megaterium OSR3和P.荧光PF-097可以有效控制南方疫病，并增加辣椒的生长和产量。