Estudo do microbioma da rizosfera de genótipos geneticamente distintos de feijão-caupi

Abstract

The rhizosphere stands out for harboring a diverse range of microorganisms and is the region where plants recruit and nourish soil microbes that, in return, secrete vitamins and growth stimulants beneficial to plants. Crop domestication and breeding, along with the conversion of natural systems into agricultural ones, may have impaired these beneficial plant–microbe interactions. In this context, studies on the microbiome of important crops, such as cowpea, can help in understanding the processes involved in the formation and organization of microbial communities, contributing to advances in plant breeding programs and agricultural production. This study aimed to characterize the microbiome associated with the rhizosphere of genetically distinct cowpea genotypes. The genetic relationship was assessed using ISSR markers and the microbiome was sequenced. The genotypes evaluated were: two biofortified cultivars enriched in iron and zinc (BRS Aracê and BRS Tumucumaque), one breeding line (MNC 03-720-C-31), and two varieties commonly used by smallholder farmers in the state of Ceará (Pingo de Ouro and Bengala). The ISSR markers allowed the separation of genotypes into two distinct groups. Group 1 included the varieties Pingo de Ouro and Bengala, while Group 2 comprised the cultivars BRS Tumucumaque and BRS Aracê and the breeding line MNC 03-720-C-31. Statistical differences in microbial richness and diversity were observed among genotypes, with the highest values found in the variety Bengala and the cultivar BRS Aracê. The cowpea genotypes showed similar bacterial communities in the rhizosphere, but with different microbial groups enriched in each genotype. However, no significant statistical differences were observed among genotypes in terms of community structure. Microbial interaction analysis revealed differences in network complexity, with genotypes Pingo de Ouro and BRS Tumucumaque showing a greater number of interactions. Most of the microbial interactions observed in the cultivar BRS Aracê were positive. The functional profile of microbial communities of the genotypes BRS Tumucumaque, MNC 03-720-C-31, and Pingo de Ouro showed a greater abundance of groups related to biological nitrogen fixation. Concluded that cowpea breeding does not significantly affect the richness, diversity, or structure of the microbial community but may influence the composition, interactions, and functions of bacterial groups.