Genotype-matched mapping reveals consistent regional flavour signatures and rhizosphere microbial correlates in...

Microbial correlates of tea terroir are often confounded by cultivar. Using eight SNP-confirmed genotype-matched pairs large-leaf tea cultivar pairs across Menghai and Pu'er, we tested whether rhizosphere communities covary with flavour chemistry during the spring flush. Under genotype control, the volatile Signature Index (VSI) was consistently higher in Menghai in all pairs, with a β-caryophyllene detection/non-detect contrast (7/8 detected in Pu'er vs 0/8 in Menghai). Non-volatiles chemistry showed a two-tier response: EGCG increased in Menghai, whereas nitrogen-associated taste allocation varied by pair. Bulk soil nitrogen and enzyme activities did not directly explain leaf patterns, while bacterial and fungal communities showed significant regional separation and cross-kingdom concordance. Within this strict genotype-matched framework, the results identify spring-flush regional flavour signatures and their microbial correlates as association-level patterns, providing candidate targets for subsequent mechanistic study.