As the primary reproductive organ of the tea plant (Camellia sinensis), the flower exhibits rich phenotypic diversity, which holds significant importance for the genetic improvement of tea varieties. In this study, 64 tea germplasm accessions were used to systematically investigate the phenotypic diversity of nine qualitative traits and twelve quantitative traits related to floral morphology. Based on 47 111 high-quality SNP markers, population genetic structure analysis and genome-wide association study (GWAS) were performed. The results revealed abundant genetic diversity in floral traits among the tested materials, with ovary villi, weight per 100 flowers, and the proportion of the bifurcation to the columella showing relatively large variation, which could serve as core evaluation indicators. Population structure analysis divided the materials into three genetic subgroups, which were highly consistent with the phenotypic clustering results. Through GWAS, 273 SNP loci significantly associated with 10 important floral traits were identified. Furthermore, five core candidate genes (GWHTASIV003067, GWHTASIV018433, GWHTASIV032688, GWHTASIV001183, GWHTASIV044042) were screened, which are involved in key biological processes such as growth regulation, RNA editing, cell cycle control, chromatin remodeling, and transcriptional regulation. This study provides, for the first time, a systematic multidimensional analysis of the genetic basis of floral traits in tea plants, offering important gene resources and a theoretical foundation for research into the molecular mechanisms of floral traits and for molecular marker-assisted breeding in tea plant.

The aging process is inevitably accompanied by a decline in muscle strength and mass, severely impairing the health and quality of life of the elderly population. Epicatechin (EC) is one of the main secondary metabolites found in tea, possesses a variety of biological activities. Previous studies have revealed the anti-aging effects of EC, but its relationship with age-related sarcopenia remains unclear. To investigate the effects and underlying mechanisms of EC on age-related sarcopenia, this study employed naturally aged C57BL/6J mice as a model. A comprehensive evaluation was conducted using a series of methodologies, including animal behavioral tests, muscle index measurements, histological analysis, Elisa assays, transcriptome sequencing and RT-qPCR validation. The results show that compared with the control group, EC treatment significantly improved the grip strength and endurance performance of aged mice (P＜0.05), and significantly increased the muscle index of the gastrocnemius, tibialis anterior, and quadriceps femoris muscles (P＜0.05). The gastrocnemius muscle fibers in the EC treated group were larger in area and more regularly arranged. EC significantly reduced the levels of the inflammatory factors IL6 and TNFα in aged mice (P＜0.05). Further transcriptomic sequencing and RT-qPCR validation reveal that EC might downregulate the expression of the BCAA transaminase gene BCAT1 and upregulate the expression of the BCAA transaminase gene BCAT2, as well as the BCAA transporter genes LAT1 and LAT2, thereby regulating muscle protein synthesis. Meanwhile, it could upregulate the expressions of skeletal muscle differentiation-related genes including MyoD, MyoG, MRF4, MCK and Myf5 to alleviate sarcopenia in aged mice.