Diversity and Functionality of Seed Vectored Bacterial Endophytes in Different Cultivars of Triticum Aestivum L. Across Ecological Boundaries

Abstract

Abstract The endophytic microbial communities of plant seeds are either early or late colonizers, from the vascular system and stigma of mother plants or through contact from the environmental niches. Microbial communities get established in the plant progenies, particularly seeds, by vertical or horizontal transmission. The composition of seed microbiome determines the type of microbial associations, ranging from mutualism to pathogenicity with the emerging plants and also, the environmental conditions have a significant effect on their diversity. Wheat associated microbiota, especially rhizobacteria and endophytes from different plant organs possess competencies for plant growth promotion, and mitigation of abiotic and biotic stress. Improved yield and adaptation, as well as sustained wheat production across different ecologies necessitate the microbiome basis for understanding the genotype-environment (G×E) interactions. Hence,we investigated the diversity and functions of culturable endophytes from different ecological conditions on seed germination and the growth and fitness of plants. The core culturable microbiome members associated with seeds were identified, and evaluated for their potential for application and ensuing colonization in wheat plants.The diversity indices such as Shannon diversity (H), Chao1, Simpson’s reciprocal index and Species evenness (J) were generally highest in the PZ, followed by the NHZ. Likewise,this study showed that the genotypes play a profound role in their diversity, with variations in the hydrolytic enzyme production, plant growth promotion and priority effects on seedling colonization of wheat. The potential for hydrolytic enzyme production also suggest the multifarious mechanisms mediated by these endophytic bacteria for colonization and antagonism against plant pathogens.