Evaluation of Germplasm Resources and Microbial Diversity Among Different Geographical Provenances of Tamarindus...

Tamarindus indica L. is a species of tree with high economic value. However, research on its associated bacterial communities is limited, and no microbial fertilizer has yet been developed specifically for tamarind. In this study, we selected 20 geographical provenances of tamarind as experimental materials, evaluated their germplasm resources, and investigated the correlation between plant traits and associated bacterial communities under grafting conditions. Provenances YM2 and BS21 produced the largest fruits, while all physiological indices showed significant variability among the tested accessions. Microbial samples from the phyllosphere and rhizosphere were collected from these 20 provenances, and 16S rRNA gene sequencing was conducted to compare microbial communities. The differences in rhizosphere microbiota among different samples were more significant than those in phyllosphere microbiota; subsequently, an in-depth investigation was conducted on the relationships between rhizosphere bacterial communities and various traits under these grafting conditions. Through correlation analysis, significant correlations were identified between some microbial phyla and the traits of tamarind under these grafting conditions. Under the current grafting conditions, variations in the rhizosphere microbiome were associated with tamarind provenances. However, due to the constraints of the experimental design, the potential influences of rootstock genotypes and scion-rootstock signal transduction could not be excluded. Nevertheless, through the unification of rootstock sources and the design of correlation analysis, this study has initially verified the dominant association between scion provenances and microbial communities.