Breeding of medicinal resources and improved varieties of Rhizoma thunbergii

Breeding of medicinal resources and improved varieties of Rhizoma thunbergii

The time of artificial domestication is not long. At present, the artificial cultivation of Rhizoma thunbergii mainly depends on the mining of wild resources as provenances and breeding materials, due to different provenances and growth years, mixed provenances, and the lack of systematic identification and evaluation of resources. especially in the genetic law research on the regulation mechanism of characters and chemical composition, it is almost blank, which leads to the breeding mainly stay in the primary stage of introduction and domestication.

Rhizoma Polygonatum is first used as a medicinal material, and its efficacy is the preferred goal of its breeding. according to the requirements of the previous edition of Chinese Pharmacopoeia, the content of effective medicinal components higher than the prescribed total amount of saponins I, Ⅱ, Ⅵ and Ⅶ is the primary goal of breeding. Secondly, due to the slow growth rate, long growth time and less dry matter accumulation, the breeding goal is to achieve the standard of Pharmacopoeia for high yield or fast growth. In nature, Zhongzhong is generally one stem and one leaf, and only once a year, with small assimilation organs, low photosynthetic efficiency and low dry matter accumulation, so the breeding of improved varieties is mostly based on large leaf area and multiple stems. In addition, wild Zhonglou grows sporadically and rarely occurs, but after large-scale cultivation, because Dianzhonglou is a perennial plant and is continuously cropped in the same plot for a long time, diseases and insect pests are easy to occur in large numbers. The main diseases found in Yunnan are leaf spot, root rot, stem rot and anthracnose, and the disease rate is up to 50%-70%. Therefore, strong disease resistance is also an important breeding goal of Zhonglou.

Based on the above breeding objectives, the Institute of Medicinal plants of Yunnan Academy of Agricultural Sciences and other scientific research institutions and enterprises, using single plant mixed selection and group mixed selection breeding, selected a new variety of Zhonglou in Yunnan. As Yunnan Province is the main producing area of Zhonglou, the new varieties are selected and bred by Yunnan scientific research institutes and related planting companies.

(2) introduction to the varieties of heavy buildings

At present, the new varieties of Zhonglou are mainly "Dianzhonglou No. 1", "Dianzhonglou No. 2" and "Dianzhonglou No. 3" selected by the Institute of Medicinal plants of Yunnan Academy of Agricultural Sciences and Lijiang Yunxin Company. New varieties such as "Yunquan No. 1" selected by Yunnan Pharmaceutical Research Institute, "Baiyao Dianzhonglou No. 1" and "Baiyao Dianzhong Lou No. 2" selected by Yunnan Baiyao Group traditional Chinese Medicine provenance breeding Co., Ltd.

1. No.1 Dianzhonglou

The single plant mixed selection method was adopted and selected for 8 years (2000-2008). The stem is purple and single stem; the total content of saponins I and Ⅱ in the rhizome is 1.8% ±0.13%, which is higher than 0.6% stipulated in the 2015 edition of the Pharmacopoeia of the people's Republic of China; the yield of more than 6 years old is as high as 2700 ~ 3300kg/hm2 (dry), resistant to leaf spot disease.

2. No.2 Dianzhonglou

The group mixed selection method was adopted and selected for 6 years (2004-2009). The stem is lavender and multi-stemmed, and the number of stems is more than 5 times that of "Dianzhonglou l", which is beneficial to asexual propagation. 6-year-old plant rhizome weight 208.04g ±93.29g (fresh), rhizome length 14.68cm ±13.46cm, rhizome, tend to 5.80cm ±1.89cm; the total amount of rhizome effective components Rhizoma saponins I and Ⅱ is 1.43 ±0.23%, which is higher than 78.8% in Pharmacopoeia. The yield in 6 years was as high as 4500-6000 kg/hm2 (dry products), which was twice that of "Dianzhonglou No. 1", and showed good resistance to leaf spot (figure 1).

1 I No.2 Dianzhong Building

3. No. 3, Dianzhong Building

The disease resistant variety with high active ingredient and high yield was selected by mixed selection method for 6 years. The total contents of saponins I, Ⅱ, Ⅵ and Ⅶ were more than 1.98% (the 2015 edition of the Pharmacopoeia of the people's Republic of China was more than 0.6%). The rhizome weight of plants over 6 years old was 198.93g ±54.04g (fresh), rhizome length 11.1.cm ±1.95cm, rhizome diameter 5.92cm ±0.93cm. The yield of more than 6 years old reached 5200-6000kg/hm2 (dry products). It had good resistance to leaf spot and stem rot and stable characters. The propagation method is seed and terminal bud cutting propagation, which is more suitable for cultivation in temperate and subtropical cold areas at an altitude of 1700-3100m, and this variety has good stability and consistency. "Dianzhonglou No. 3" is similar to "Dianzhonglou No. 2".

4. Yunquan No. 1

From the high-quality multi-bud provenance of Zhonglou in northwest Yunnan, after 6 years of systematic breeding, it was found that the meristematic advantage of multi-bud stem was obvious, the main rhizome was stout and the root system was developed and vigorous, and the differentiation rate of multiple plant buds at the head of main root stem was fast and uniform. each year, the tip of each stem or lateral bud can differentiate into two buds, the plant bud is strong, and the stem grows neatly. It can form 4-8 stout rhizome buds for ramet breeding in two years; in spring, summer and autumn, stem buds and plants grow neatly, strong seeds are not easy to lodge, and seed setting rate and plumpness rate are higher. The average content of active ingredients is 2.43%, which is higher than the index content of Rhizoma Polygonatum saponins (the 2015 edition of Chinese Pharmacopoeia is more than 0.6%). The average yield per mu reaches 710.5kg, which is higher than 150%-300% of the yield of similar varieties, and has good stability and consistency, so it is more suitable for cultivation in cool areas at 1700-3100m above sea level in temperate and subtropical zones. Yunquan No. 1 is similar to Dianzhonglou No. 2 (figure 2) [Jishan Huayao].

Yunquan No.1

At present, "Dianzhonglou No. 2" and "Yunquan No. 1" are regarded as excellent varieties with high yield and high quality, which are highly respected by growers.