Effects of Polygonatum polygonatum seedlings of different ages on their agronomic characters and yield

Effects of different age on agronomic characters and yield of Polygonatum multiflorum seedlings

Fund Project: Construction Project of Seed and Seedling Breeding Base of Traditional Chinese Medicine Needed by National Essential Drugs ( 2015SZ0034) ;

Basic scientific research project of public welfare scientific research institutes in Sichuan Province (A2015N6) ;

Miao Zi Project of Science and Technology Department of Sichuan Province (2016RZ0061) ;

Sichuan Province Traditional Chinese Medicine Raw Material Quality Inspection Technology Service Center sub-project "Polygonatum commodity specification grade research project";

The Fourth National Survey Project of Traditional Chinese Medicine Resources ( 2017 PC010) Polygonatum polygonatum Hua, also known as wild ginger and ginger polygonatum, is a perennial herb belonging to Polygonatum of Liliaceae, which is included in Chinese Pharmacopoeia (Volume I of 2015 Edition). More than 40 species of Polygonatum have been found, mainly distributed in the north temperate zone, and about 31 species in China. Polygonatum multiflorum has the functions of invigorating qi and nourishing yin, invigorating spleen, moistening lung and benefiting kidney. It is produced in Sichuan, Guizhou, Hunan, Hubei, Henan and other places. Polygonatum multiflorum artificial cultivation often used tuber reproduction, with a large seed quantity. It has been reported that the germination rate of Polygonatum sibiricum seeds is very low, generally does not emerge in the first year, dormancy after 2 winters, only one true leaf can be produced, from seed sowing to receiving medicinal materials for 5 ~ 6 years, therefore, although the seed harvest is large, it is almost unnecessary in production. Zhang Wangfan and Zhao Zhi broke the dormancy of Polygonatum multiflorum seeds by GA3 and cold storage respectively, and the germination effect was good. However, there is no report on the suitable transplanting period of Polygonatum multiflorum seed after seedling raising, and the changes of its growth and yield after transplantation.

This study intends to transplant Polygonatum multiflorum seedlings of different ages, and determine the best transplanting age of Polygonatum multiflorum seedlings by investigating the survival rate of seedlings after transplantation and the growth after transplantation, so as to provide theoretical support for the seed seedling transplantation technology of Polygonatum multiflorum.

1 Materials and methods

1. 1. Overview of test area The test base is located in the seed and seedling breeding base of national essential drugs (Guang 'an, Sichuan Province) in Yuechi County, Guang' an City, Sichuan Province. Yuechi County is located in the triangular platform at the confluence of Qujiang River and Jialing River in the east of Sichuan Basin, 30°15'~ 30° 48'N and 106°7' ~ 106° 44'E. Yuechi territory without complete mountains, broken terrain, rolling hills, valleys crisscross. The terrain is high in the northwest, low in the southeast, and gradually forms low mountains and narrow valleys, middle hills and wide valleys with dams in the northwest. From the tail of Pengangang Ridge to Jincheng Mountain in Yuechi County from the east, around the northwest to Huanglongzhai and Wanjiagou area is a low mountain area, covering an area of 417. 68 km2, accounting for 28. 76%, elevation is 600 ~800m, hills are mostly broken land, narrow valleys are formed among mountains, and the ground slope is large. The water quality, soil, air and indicators in this area all meet the national standards required by the Quality Management Code for the Production of Chinese Medicinal Materials.

Polygonatum multiflorum is a shade-loving plant and grows mostly in the forest. Therefore, the experiment of transplanting Polygonatum multiflorum seedlings under the forest was set up. By comparing with field experiment, the influence of environment on the growth and development characteristics of transplanted seedlings was proved. The test was carried out in 2017. The field test area was selected in the sandy soil with fertile soil, good irrigation conditions and farm manure; the under-forest test area was selected under the cypress forest with thick humus layer, fertile soil and relatively high humidity, and the forest edge grew with Lygodium, walnut, wild Polygonatum, etc.

1. 2 Test materials The test materials were from the seed seedling base of Chinese herbal medicine required by the national essential drugs (Guang 'an, Sichuan), and were healthy seedlings of Polygonatum multiflorum for one year, two years and three years of seed breeding.

1. 3. Experimental design The experimental plots were set in field and under cypress forest. 0m × 3. 0 m, plant spacing 20cm, row spacing 30cm, depth 10cm, transplanting one-year, two-year, three-year seedlings respectively, 100 plants/square, protection row between square and square, width 1m, repeat 3 times. Transplanted on March 20, 2017, and observed the emergence rate and growth and development of Polygonatum multiflorum seedlings after transplantation. On April 10, waxy corn was planted on protected rows.

1. 4 Determination indicators and methods On July 9, 2017, the emergence of Polygonatum multiflorum seedlings in fields and cypress forests was investigated, and the emergence rate was counted. 30 plants were selected randomly from two experimental plots and their plant height, leaf length, leaf width, leaf area, tuber length, tuber diameter, fresh weight of aboveground part and fresh weight of underground part were measured.

2 Results and analysis

2. 1 The emergence rate of Polygonatum multiflorum seedlings of different ages under different treatments can be obtained from Table 1. The emergence rates of one-year, two-year and three-year seed propagation Polygonatum multiflorum seedlings in the field are: 0. 33%、5. 50%、6. 50%, the emergence rate under the forest is: 3. 00%、43. 30%、30. 70%, indicating that the seedling emergence rate of one-year, two-year and three-year seedlings transplanted in field and under forest was larger, and the seedling emergence rate under forest was higher than that of seedlings transplanted in field at the same age. The seedling emergence rate of annual Polygonatum multiflorum seedlings was low in field and under forest, so it might not be suitable for transplantation. There was a big difference in emergence rate between field and understory after transplanting two-year seedlings. 50%, much less than 43. 30%, indicating that the newly transplanted seedlings of two years old are suitable for growth under the forest. The difference of emergence rate between field and understory was also obvious after transplanting 3-year-old seedlings. The emergence rate in field was 6. 50%, greater than 0. 33%, less than 8. 50% and 30. 70%, greater than 3. 00%, less than two-year 43. 30%。The results showed that the seedling rate of two-year-old seedlings transplanted under forest was the highest, and it was the most suitable age for transplantation.

2. 2. Differences in agronomic characters and yield of Polygonatum multiflorum seedlings under different treatments. The agronomic characters and yield measurement indexes of Polygonatum multiflorum seedlings transplanted to field and under forest are as follows. It can be seen from Figure 1 that under field environment, the 8 indexes are respectively: three years> two years> one year, indicating that three years of seedling life of Polygonatum multiflorum is more suitable for field growth. From Figure 2, except plant height, leaf length and leaf width, which increased continuously with the increase of seedling age, the other five indexes increased first and then decreased, indicating that the seedling age of Polygonatum multiflorum under the forest was more suitable for two years. From Figure 3 and Figure 4, the 8 indexes of annual and biennial Polygonatum multiflorum seedlings showed a trend of increasing gradually in field and under forest, and the indexes of biennial seedlings under forest were the highest, indicating that biennial seedlings grew better than annual seedlings in field and under forest. From the analysis of Fig. 5, it is concluded that except plant height, leaf length and leaf area of three-year-old Polygonatum multiflorum seedlings, the other five indexes under forest are larger than those in field, indicating that three-year-old seedlings are more suitable for transplantation in field. The results showed that the 3-year-old seedlings of Polygonatum multiflorum were suitable for field transplantation, and the 2-year-old seedlings of Polygonatum multiflorum were suitable for forest transplantation.

Table 1 Emergence rate of Polygonatum multiflorum seedlings in different years under different treatments

Fig. 1 Agronomic characters and yield of Polygonatum multiflorum seedlings treated in field

Fig. 2 Agronomic characters and yield of Polygonatum multiflorum seedlings treated under forest

Fig. 3 Agronomic characters and yield of one-year-old Polygonatum multiflorum seedlings treated in field and under forest

Fig. 4 Agronomic characters and yield of biennial Polygonatum multiflorum seedlings treated in field and under forest

Fig. 5 Agronomic characters and yield of three-year-old Polygonatum multiflorum seedlings treated in field and under forest

3 Conclusions and discussion

The results showed that two-year-old seedlings had the highest seedling rate under forest, which was the most suitable age for transplantation. The seedlings of Polygonatum multiflorum at 3 years old are suitable for field transplantation, and those at 2 years old are suitable for under forest transplantation. Wang Qiang, Bi Yanwen and Li Shi found that wild Polygonatum sibiricum grew well in undergrowth shrubs or hillside shade. In this study, the comparative analysis of biological indexes of Polygonatum multiflorum transplanted to field and under forest showed that the emergence rate, agronomic characters and yield of Polygonatum multiflorum seedlings under forest were better than those in field, which indicated that the environment under forest was more suitable for the growth of Polygonatum multiflorum, but the three year old Polygonatum multiflorum seedlings under forest were larger than those in field except plant height, leaf length and leaf area, and the other five indexes were smaller than those in field. This may be because the waxy corn in the early shade has not grown up or grown up, the seedlings are directly exposed to sunlight, the soil temperature and humidity change quickly and the seedlings are difficult to adapt to the environment, and the three-year seedlings themselves are stronger than the one-year and two-year seedlings, and it is easier to adapt to the field environment, so they will grow better than the forest. Therefore, suitable conditions for the growth of Polygonatum multiflorum should be created as far as possible when planting in the field, and measures such as shading treatment, timely watering to maintain soil moisture and application of organic fertilizer should be taken in the early stage of growth to provide good conditions for the growth of Polygonatum multiflorum and ensure the emergence rate.

Overall analysis shows that seed breeding young polygonatum multiflorum seedlings are not suitable for transplantation, because its seedlings are weak, have grown buds and fibrous roots when transplanted in spring, easy to hurt roots, buds, reduce survival rate.