Systematic evaluation of landrace tea populations in Northern Sichuan, China, based on morphology, DNA markers, and biochemistry analyses

Abstract

Landrace tea populations are important recourses for germplasm conservation and selection of elite tea clone cultivars. To understand their genetic diversity and use them effectively for breeding, two traditional landrace tea populations, Beichuan Taizicha (BCTZ) and Nanjiang Dayecha (NJDY), localized to northern Sichuan, were evaluated for morphological characters, simple sequence repeat (SSR)–based DNA markers and the contents of biochemical components. A wide range of morphological variation and a moderately high level of DNA polymorphism were observed from both BCTZ and NJDY. NJDY had on average, bigger leaves, larger flowers, higher total catechins (TCs), and greater gene diversity (GD) than BCTZ. Interestingly, samples from BCTZ had a wide range in the ratio of galloylated catechins to nongalloylated catechins (G/NG) (1.83–8.12, CV = 48.8%), whereas samples from NJDY were more variable in total amino acid (TAA) content (25.3–50.8 mg·gL1 dry weight) than those from BCTZ. We concluded that the two Camellia sinensis landrace populations are of great interest for both individual selection breeding and scientific studies.