Relationship between leaf pigment content and leaf color parameters in tea tree germplasm

Abstract [Objective] This study aims to investigate the relationship between leaf pigment content and leaf color parameters of tea germplasm resources, and to provide theoretical basis for the exploration of leaf color presentation mechanism as well as variety selection and breeding of leaf color-specific tea germplasm resources. [Methods] The spring shoots of 143 leaf color-specific tea germplasms with yellow, albino, and purple variation were used as materials from the Tea Germplasm Resource Nursery of Zhejiang Province. The value of L* , a* , and b* of leaf color parameters and the pigment content of total anthocyanin, chlorophyll, and carotenoid were analyzed. Through principal component analysis, cluster analysis, correlation analysis, multiple stepwise regression analysis, and pathway analysis, the relationship between leaf pigment content and leaf color parameters was explored. [Results] (1) The purple tea tree germplasms had higher anthocyanin content and a* value, and the leaves showed purple-red color. The ratio of carotenoid content to chlorophyll content and b* value in yellow germplasms were higher, and the color of leaves were yellow; the albino germplasms had higher L* value, and the color of leaves were white; and the chlorophyll content of the yellow and albino tea tree germplasms was lower. For leaf color phenotypic traits, the leaf color specific tea tree germplasms were generally clustered into two groups: the white and yellow series in one group, and the purple series in another group. (2) The leaf color parameter a* value of the leaf color specific tea tree germplasms exhibited highly significant positively correlation with anthocyanin content, while L* value as well as b* value had highly significant negatively correlation with anthocyanin and chlorophyll content; the b* value was highly significant positively correlated with the content of carotenoid. Anthocyanin and chlorophyll had a greater direct effect on the value of the leaf L* , a* , b* . [Conclusion] The a* value can be used for describing the leaf purple-red traits, while the b* value for the leaf yellow traits.