Study on the grading standard of Panax notoginseng seedlings

Abstract

Background: The quality differences in seedlings of medicinal herbs often affect the quality of medicinal parts. The establishment of the grading standard of Panax notoginseng seedlings is significant for the stable quality of medicinal parts of P. notoginseng.

Methods: To establish the grading standard of P. notoginseng seedlings, a total of 36,000 P. notoginseng seedlings were collected from 30 producing areas, of which the fresh weight, root length, root diameter, bud length, bud diameter, and rootlet number were measured. The K-means clustering method was applied to grade seedlings and establish the grading standard.

Results: The fresh weight and rootlet number of P. notoginseng seedlings were determined as the final indices of grading. P. notoginseng seedlings from different regions of Yunnan could be preliminarily classified into four grades: the special grade, the premium grade, the standard grade, and culled seedlings.

Conclusion: The grading standard was proven to be reasonable according to the agronomic characters, emergence rate, and photosynthetic efficiency of seedlings after transplantation, and the yields and contents of active constituents of the medicinal parts from different grades of seedlings.

Keywords: Panax notoginseng; field test; grading standard; seedling.

Fig. 1

Appearance of Panax notoginseng seedlings. (A) Group seedling. (B) Long seedling. 1, 2, 3, and 4 refer to the rhizome, lateral root, root tuber, and fibrous root of P. notoginseng, respectively.

Fig. 2

A total of 36,000 P. notoginseng seedlings were collected from 30 producing areas, of which agronomic characters were measured. The normal distribution plots of P. notoginseng seedlings agronomic characters were made by SPSS21.0. (A) Root length. (B) Root diameter. (C) Bud length. (D) Bud diameter. (E) Number of rootlets. (F) Fresh weight.

Fig. 3

Emergence rates of different grades of Panax notoginseng seedlings after transplantation of 60 days. The orthogonal design of L₉ (3⁴) was used in the plots. Twelve plots randomly permuted were set up. The graph shows the mean ± standard deviation of at least three independent experiments.*p < 0.05 and **p < 0.01, compared with the special grade; Δ p < 0.05 and ΔΔ p < 0.01, compared with the premium grade.

Fig. 4

Fresh weight/dry weight (FW/DW) ratios of Panax notoginseng seedlings of different grades at different growth stages. (A) Root, stem, and leaf. (B) Total biomass. Each graph shows the mean ± standard deviation of at least three independent experiments. *p < 0.05 and **p < 0.01, compared with the special grade; Δ p < 0.05 and ΔΔ p < 0.01, compared with the premium grade.

Fig. 5

The yields, size, and roots number per 500 g of Notoginseng Radix samples from Panax notoginseng seedlings of different grades collected from different plots in late April 2016. (A) Yields. (B) Size. (C) Number of roots per 500 g. Each graph shows the mean ± standard deviation of at least three independent experiments. *p < 0.05 and **p < 0.01, compared with the special grade; Δ p < 0.05 and ΔΔ p < 0.01, compared with the premium grade.

Fig. 6

Content of total saponins and contents of saponins of Notoginseng Radix samples from P. notoginseng seedlings of different grades planted for 2 years. (A) Total saponins. (B) Contents of saponins. Each graph shows the mean ± standard deviation of at least three independent experiments. *p < 0.05 and **p < 0.01, compared with the special grade; Δ p < 0.05 and ΔΔ p < 0.01, compared with the premium grade.