Abstract:

In view of the current situation of no standard and improper use of Polygonatum cyrtonema’s stem tuber in China, the effects of stem size and age on yield and medicinal quality of P. cyrtonema were studied, aiming to provide a theoretical basis for seed selection and use of P. cyrtonema. A two-factor randomized block design was conducted with stem size as the main factor and age as the other factor. P. cyrtonema’s stem tuber number of shoots, length, diameter, and weight were used as indicators, and the K-means clustering method was adopted to divide the stem tuber into 3 specifications and 3 ages. By investigating the changes in seedling emergence rate, yield per plant, yield per unit area, and tuber polysaccharide content, we analyzed the differences of yield and medicinal quality of two-year-old P. cyrtonema’s under different stem tuber sizes and ages. The results show that the stem tuber size and age are correlated with seedling emergence rate; the stem size is extremely and significantly correlated with yield per plant and yield per unit area; the stem age is significantly correlated with yield per plant and yield per unit area; the stem size is extremely and significantly correlated with polysaccharide content; and the stem age is correlated significantly with polysaccharide content. It is speculated that there is an interaction between the stem size and age, and stem tuber with high specification and low age is suitable for planting, which could significantly improve the yield and medicinal quality of P. cyrtonema.

Key words: K-means clustering method, Polygonatum cyrtonema, size of stem tuber, age of stem tuber, yield, medicinal quality