Fungal community of multiple compartment niches in spring rapeseed (Brassica rapa L. and Brassica napus L.) responses to different cultivars on the Qinghai-Tibet Plateau, China

Abstract

Abstract Background Spring rapeseed has developed specific associations with fungi to adapt to extreme environments on the Qinghai-Tibet Plateau (QTP). However, the correlation among rapeseed, fungi and soil on the QTP remain largely unexplored. Methods This study comparatively analyzed the fungal diversity and community in multiple compartment niches (rhizosphere soil, root, stem and leaf) in Brassica rapa L. (Haoyou No. 11) and Brassica napus L. (Qingza No. 4, Qingza No.5, Qingza No. 7, Qingza No. 9, Qingza No. 12 and Qingza No. 15). Internal transcribed spacer (ITS) genes were sequenced by High-throughput Illumina sequencing, followed by function prediction using FUNGuild. Results B. napus exhibited higher fungal diversity in plant tissues than B. rapa, while B. rapa demonstrated higher fungal richness in the rhizosphere soil (p < 0.05). Olpidium (66.29%), Lactarius (18.37%), and Verticillium (1.99%) were the most abundant genera, and 46 key genera prevalent in all niches and cultivars. Additionally, 19 biomarkers were identified, with Lactarius, Coprinellus, Mortierella and Vishniacozyma significantly enriched in cultivars Qingza No. 15, Qingza No. 12, Qingza No. 7, and Qingza No. 4, respectively, while Haoyou No. 11 harbored 15 other genera. Among them, Saprotroph-Symbiotroph (45.00%) as the dominant guild in the rhizosphere soil. Correlation network analysis indicated that the abundant and key genera showed significantly positive correlations with yield, and fungal biomarkers may contribute to the promotion of plant growth and stress resistance in rapeseed (p < 0.05). Conclusions This study provides valuable insights into the relationship between rapeseed and fungal communities on the QTP.