Genotype-by-Environment Interaction and Stability Analysis for Four Functional Compounds in Tea Chrysanthemums: A Three-Year Study

Chrysanthemum contains numerous active compounds, including flavonoids and phenolic acids, with its dried capitula widely used for tea and medicinal applications. The content of functional compounds is readily influenced by environmental factors, and the use of varieties with high-level and stable bioactive compounds is essential for sustainable cultivation. However, a key challenge is identifying genotypes that consistently perform well for functional-component traits in contemporary breeding activities. This study aimed to evaluate the performance and stability of functional components in tea chrysanthemums across multiple years. Total flavonoids, chlorogenic acid, luteoloside, and isochlorogenic acid A were investigated in 24 tea chrysanthemum accessions across three growing years of 2018, 2021, and 2022. The additive main effects and multiplicative interaction (AMMI) model analysis revealed significant genotype (G), environment (E), and genotype-by-environment interaction (GEI) effects for all functional traits across three growing years. The GEI accounted for 63.58% to 80.82% of the variation across the four components in the AMMI model. Based on the AMMI stability value (ASV) parameter, the tea chrysanthemums showing the most stable concentrations of total flavonoids, chlorogenic acid, luteoloside, and isochlorogenic acid A were identified. Based on phenotypic values and stability results, Suju-6, Hongxinju, Wangongju, and Baixiaoxiangju performed relatively well across the functional components investigated, making them promising candidates for future breeding and promotion programs. These findings provide valuable insights into the genetic basis of functional elements in tea chrysanthemum and will contribute to further genetic improvement.