Genotype–Environment Interactions for Tree Growth and Leaf Phytochemical Content of Cyclocarya paliurus (Batal.) Iljinskaja

Abstract

Cyclocarya paliurus (Batal.) Iljinskaja, as a woody tree species, has various health-promoting phytochemicals and is commonly used in tea production in China. A field trial for C. paliurus was conducted at two typical sites to evaluate genotype × environmental interaction (GEI) effects and identify the stability and adaptability of 13 families. The genotype main effects and genotype × environment interaction effects (GGE) were used to analyze the GEI effects for tree height, diameter at breast height (DBH), and leaf flavonoid and triterpenoid contents. Two-way analysis of variance indicated that the tree growth and leaf phytochemical contents were mainly affected by genotype and GEI. Based on the results of GGE, the JH1 family had high mean values and high stability in total flavonoid and total triterpenoid accumulations, while the KM4 family exhibited high means and high stability in tree height and DBH growth, as well as high means and medium stability in total triterpenoid content. Pearson’s correlation analysis indicated that the annual mean DBH was significantly and positively correlated with leaf phytochemical content in C. paliurus when all data for the 13 families at the two sites were used. Our results suggest that JH1 should be mainly extended as a superior genotype for the production of flavonoids and triterpenoids in the leaves, while KM4 could be spread for timber production or leaf triterpenoid production. This study provides useful information on the selection of C. paliurus genotypes in target sites and cultivation strategies for establishing oriented plantations.