[Studies on classification criteria of Codonopsis pilosula var. modesta seedlings in southern of Gansu]

To reveal the quality grade of Codonopsis pilosula var. modesta seedlings from Gansu and provide the scientific basis for establishment of the seedling quality classification standard.

Thirty batches of C. pilosula var. modesta seedlings collected from varied producing area of Gansu were selected as testing materials, the fresh weight of single plant, water content, length of seedling, diameter of seedling, length of bud and number of buds were determined and the grading standard were systemically analyzed by K-Means Cluster.

The C. pilosula var. modesta seedlings could be divided into 3 grades of criteria, i. e. the first-grade seedlings were at least 14.1 g of the fresh weight of seedling, 24.0 cm of length of seedling, 1.17 cm of diameter of seedling; the second-grade seedlings were 14.0-3.5 g of the fresh weight of seedling, 23.9-21.6 cm of length of seedling, 1. 16-0. 68 cm of diameter of seedling; the third-grade seedlings were 3.4-1.9 g of the fresh weight of seedling, 21.5-13.5 cm of length of seedling, 0.67-0.54 cm of diameter of seedling.

Among 30 batches of C. pilosula var. modesta seedlings, 66.7% of the seedlings belonged to the first and the second grades. It suggests that the first and the second grade seedlings should be used in the standard production.