Abstract

The study was conducted to comprehend the facets of culturable endophytic diversity correlating with the fitness of cultivar. Tomato bacterial endophytes from cultivars Arka Rakshak (AR; multi-disease tolerant hybrid) and Pusa Ruby (PR; susceptible check) were isolated. Molecular identification quantified that only two genera Rhizobium and Bacillus were common in both cultivars out of fifteen genera isolated. Genera Microbacterium, Enterobacter, Falsibacillus, Cohnella, Youhaiella, and Fluviicola were found only in AR, whereas genera Chryseobacterium, Pseudomonas, Dyadobacter, Staphylococcus, Micrococcus, Microvirga, and Shinella were found only in PR. Although the genera level diversity indicated cultivar specificity, except for firmicutes (7 in AR and 4 in PR), the distribution of taxonomic class alphaproteobacteria, gammaproteobacteria, bacteroidetes, and actinobacteria was almost similar. Gram-positive class was dominated by firmicutes and Gram-negative by alphaproteobacteria in both cultivars. On contrary, the collective functional profile for the production of hydrogen cyanide, ammonia, and siderophore, apart from phosphate solubilization and indole acetic acid production, indicated the dominance of endophytes from AR (multi-disease tolerant hybrid). The pattern of antagonistic ability against 15 different strains of R. solanacearum indicated that endophytes from tolerant cultivar exhibit higher in vitro suppression. The number of antagonists and the extent of inhibition both were higher in AR endophytes. However, the genetic capability for harboring eight antimicrobial compounds producing genes was found to be well distributed in both cultivars. Results showed that the functional aspects of these bacterial endophytes correlate with cultivar fitness more than that of taxonomic and genetic diversity.

Graphic abstract

中文翻译：

---

栽培植物内生菌的分类和功能多样性，以其对青枯菌的适应性

摘要

进行该研究以了解与栽培品种的适合性相关的可栽培内生多样性的方面。从品种Arka Rakshak（AR；耐多病害的杂种）和Pusa Ruby（PR；易感性检查）中分离出番茄细菌内生菌。分子鉴定量化了在分离的十五属中两个属中仅根瘤菌属和芽孢杆菌属是共同的。属微杆菌，肠杆菌属，Falsibacillus，Cohnella，Youhaiella和Fluviicola仅见于AR，而属金黄杆菌，假单胞菌，仅在PR中发现了DY，细菌，葡萄球菌，葡萄球菌，微球菌，Microvirga和Shinella。尽管属水平的多样性表明了品种的特异性，除了硬毛虫（AR中有7种，PR中有4种）外，分类学类别α变形杆菌，γ变形杆菌，拟杆菌和放线菌的分布几乎相似。在两个品种中，革兰氏阳性类以硬毛虫为主，革兰氏阴性类以α蛋白杆菌为主。相反，除了磷酸盐增溶和吲哚乙酸的生产外，用于生产氰化氢，氨和铁载体的总体功能特征表明，AR（多病耐性杂种）的内生菌占主导地位。。对青枯菌15种不同菌株的拮抗能力模式表明，来自耐性品种的内生菌具有较高的体外抑制作用。在AR内生菌中，拮抗剂的数量和抑制程度均较高。然而，发现携带八个产生抗菌化合物的基因的遗传能力在两个品种中均分布良好。结果表明，这些细菌内生菌的功能方面与品种适应性的相关性比分类学和遗传多样性的相关性高。

图形摘要