关键词: 表型性状, 生物活性物质, 性状相关, 稳定性评价, 优树选择

Abstract:

【Objective】 Based on two-round selections for phenotypic characteristics of Cyclocarya paliurus (first-round) and the content of bioactive substances in their leaves (second-round), the superior individuals were screened out through an evaluation of annual stability of bioactive substance contents over two consecutive years. These individuals would be taken as good planting materials for the production of bioactive materials of C. paliurus.【Method】Superior individuals were selected in the first-round in March 2017 based on phenotypic traits, including leaf color, shape and size; angle of the first lateral branch; crown shape (flat and round) and superior provenance. The total flavonoids, triterpenoids, and water-soluble polysaccharides in the leaves of the selected trees were determined in September 2017. After the improvement potential of the selected individuals was evaluated, these selected trees were taken as the basis of the second-round selection. In September 2018, the content stability of bioactive substances was assessed for the second-round selected trees to determine the final elite individuals.【Result】The contents of the main bioactive substances in leaves of 36 selected individuals were significantly different in the first-round selection phase, and the improvement potential of the total flavonoids, total triterpenoids and water-soluble polysaccharides was 34.3%, 43.43% and 36.41%, respectively. In the second-round selection, ten individuals were screened based on the combination of single and multiple indexes from the first-round selected individuals. Finally, three elite individuals with stable contents, including LC1, LC4 and CP3, were determined by comparing the contents of the main bioactive substances in the leaves over two consecutive years. The correlation analysis indicates that tender leaves in red are positively correlated with high contents of the total flavonoids and triterpenoids, while the total triterpenoids are significantly correlated with the larger branch angle and round crown. However, the content of water-soluble polysaccharides is no correlated with the observed phenotypic traits.【Conclusion】Owing to the positive correlation of phenotypic traits with a high content of main bioactive substances in the leaves, tender leaves in red, plant with a large branching angle and round crown were taken as the selection basis of the superior individuals for medicinal use of C. paliurus. The contents of the main bioactive substances in three final selected elite individuals (LC1, LC4 and CP3) were higher than those of others, and kept stable over two consecutive years. To ensure the high and stable yield of the bioactive substances in the selected plants, it is necessary to study the interaction effects between the genetic and environment in multiple habitats for further selecting suitable planting areas and corresponding cultivation strategies.

Key words: phenotypic traits, bioactive substance, traits correlation, stability evaluation, selection of superior individuals