Study on the Quality Component Differences Among Tea Cultivars in Northern Guizhou

To elucidate how quality is reshaped in introduced tea varieties under Guizhou’s unique ecological conditions and to identify quality advantages and flavor differences between exotic and local germplasm resources, this study investigated the quality characteristics of tea plant germplasm from different geographic origins under Guizhou’s ecological conditions. Quality components and volatile aroma compounds were analyzed in four introduced cultivars (CC4H, SLX, SMCY, HJC1) and two local cultivars (QM601, GZSC). Sensory evaluation indicated that CC4H, SMCY, and HJC1 were more suitable for manufacturing premium green tea in the local area. GC-MS identified 147 volatile compounds, with alcohols present at the highest concentrations (1090.69–1499.18 μg/kg). SMCY had the highest total alcohol content. rOAV analysis confirmed that benzaldehyde, (E)-β-damascone, β-ionone, and 1-octene-3-one are the key contributors to the aroma profile. Among the introduced cultivars, SMCY stands out for its floral and aromatic compounds; SLX is notably rich in floral and fruity aldehydes and esters; CC4H has a distinct roasted sweetness, and HJC1 offers the best freshness. The local variety QM601 exhibits synergistic accumulation of tea polyphenols and fruity terpenes, while GZSC maintains its traditional advantage in the balance of phenolic and amino compounds. These findings provide a theoretical basis for the differentiated deployment of tea cultivars in Guizhou’s tea-growing regions.