High-throughput sequencing-based profiling of endophytic bacterial community composition and diversity in seeds of Yunnan cytoplasmic male-sterile rice.

As an important food crop in China, hybrid rice is of significant importance for national food security and supply. Cytoplasmic male-sterile (CMS) rice is a key component of hybrid rice technology, while plant endophytes, especially seed endophytes, play a crucial role in promoting plant growth and reproduction. Therefore, understanding the diversity and community structure of seed endophytes in CMS rice is essential for hybrid rice technology. However, relevant research in this area remains scarce. This study systematically analyzed the diversity and community structure characteristics of seed endophytic bacteria in 14 Yunnan CMS rice varieties (totaling 42 samples) based on Illumina NovaSeq 6000 high-throughput sequencing technology, aiming to elucidate the core microbial community structure and diversity. A total of 503 operational taxonomic units (OTUs) were identified. At the phylum level, the dominant microbial groups in all samples were Proteobacteria (relative abundance 91.53-99.95%). At the genus level, the core microbial community consisted of Pantoea (64.29-93.11%), Xanthomonas (1.08-16.97%), and Kosakonia (0.46-12.66%). Both α- and β-diversity analyses revealed no significant inter-line differentiation, indicating a highly stable and conserved endophytic bacterial community across the Yunnan CMS rice germplasm. This study provides the first comprehensive characterization of the seed-associated core microbiome of Yunnan CMS rice lines.