What are the characteristics of Rehmannia glutinosa?

Glutinous rice wine. Also known as Huaiqing Dihuang, Hickory Flower and Shan Yan Root. It is a perennial herb of Scrophulariaceae. Cultivated in Ming Dynasty (1590), it is mainly produced in wen county, Mengxian, Wuzhi, Aibo and Qinyang, Henan Province, with large output and good quality. It is sold all over the country and exported in large quantities. In addition, Liaoning, Hebei, Shandong, Zhejiang and other provinces mainly produce wild rehmannia glutinosa. Take root tuber as medicine. It mainly contains β-sitosterol, mannitol, catalpol, stigmasterol and vegetable oil. Sterol, Rehmannia glutinosa, alkaloids, fatty acids, glucose, vitamin A substances, stachyose, arginine and γ -butyric acid. The root of Rehmannia glutinosa also contains mannitol and stachyose, 0. 1 1% catalpol and sucrose, 4.2% arginine and 3.0%γ- butyric acid. Animal pharmacological experiments show that Rehmannia glutinosa extract or root extract has the functions of lowering blood sugar, contracting and dilating blood vessels, while alcohol extract has the functions of lowering blood pressure, preventing glycogen reduction, protecting liver and promoting blood coagulation. It has certain inhibitory effect on some pathogenic fungi. Sweet and bitter, warm and cold in nature, it has the functions of clearing away heat and promoting fluid production, cooling blood and moistening dryness, nourishing yin and tonifying kidney, regulating menstruation and enriching blood. It can be used for treating fever due to yin deficiency, thirst quenching, hematemesis, epistaxis, metrorrhagia, irregular menstruation, restless fetal movement, constipation due to yin injury, etc.

One. morphological character

The height of the plant is 0.2-0.4m, and the whole plant is covered with gray hairs and glandular hairs. The roots are thick and fleshy, in the form of blocks, cylinders or spindles, and the basal leaves are clustered. The leaves are obovate-lanceolate or oblong, with a length of 3- 10 cm and a width of 1.5-4 cm. The tip is blunt, the base gradually narrows, the lower part grows into a petiole, the edge has irregular blunt teeth, and there are many wrinkles on it Flowering stems erect, solitary or 2-3 branched; Bracts leaflike, 1 to several, racemes, hairy flowers, bell-shaped calyx, ca. 1.5cm long, 5-lobed at the apex, triangular lobes, slightly irregular; Corolla is broadly tubular, slightly curved, 3-4 cm long, purplish red or light purplish red, sometimes pale yellow, 5-lobed at the apex, slightly lipped, 4 stamens, 2 strong, superior ovary, ovoid, 2-loculed, simple style. Capsule is ovoid or ovoid, with sharp apex, persistent style, surrounded by persistent calyx, and many small seeds (Figure 14-73).

Figure 14-73 Morphological diagram of Rehmannia glutinosa

Second, biological characteristics.

Growth and development characteristics

1. Growth and development of sexual organs

Almost 100% of the plants overwintering in the field can bloom whether planted in spring or inverted in summer. Beijing turned green in late April, and gradually became cold in May, reaching about 40 cm in June.

Most flowers bloom in the daytime (8- 17). Pollen ripens at anther dehiscence and can germinate on pistil stigma. The stigma is mature when the flower just opens but does not spread. Mature pollen of different varieties can bear fruit on the day of emasculation, the second day or the third day. In June, when the pollen was stored at room temperature in Beijing for 65,438+0.20 hours, 28% of the pollen still germinated. When it is stored in the refrigerator for one month, the pollination rate is still high. The seed setting rate of self-pollination and intraspecific hybridization is very low, while the seed setting rate of artificial hybridization between varieties is over 90%, and the seed setting rate of insect pollination can reach 92%. However, if insects are isolated with wire fences, they will not bear fruit (table 14-72), which shows that Rehmannia glutinosa is not an anemophilous flower, but a cross-pollinated plant pollinated by insects and has self-incompatibility. However, mixing different kinds of dead pollen can improve the seed setting rate of self-pollination. After cross-pollination of Rehmannia glutinosa, the corolla wilted and fell off, the ovary began to expand into a cone shape, the capsule was green, brown when it matured, naturally cracked, and many small brown seeds were scattered. Pollination until the seeds mature for about 30 days.

Table 14—72 Comparison of Seed Setting Rate of Rehmannia glutinosa by Different Pollination Methods

2. Growth and development of seedlings

Rehmannia seeds can be sown when they are mature. After germination, two small leaves will grow first, and then real leaves will grow. In Beijing, seedlings emerged in 8-9 days in early spring, and the survival rate of transplanting reached over 96%. By mid-June, each plant has 8- 13 true leaves, which are rosette-shaped. By mid-July, each plant has 28-30 real leaves, and these leaves no longer grow. Until the middle of August, the leaves gradually withered, and by the end of September, they fell to about 20 pieces. Seedling growth is vigorous, leaf growth reaches the peak earlier, and lasts for a long time, and aging is slow, so photosynthesis takes a long time and has a large leaf surface, which is beneficial to the accumulation of dry matter in roots. While growing with the aboveground parts, the roots are also growing and expanding. First, spindle-shaped taproots grow, with a length of 7 7- 10/0cm and a thickness of1-2cm. Several fibrous roots grow on the main roots, and the fibrous roots gradually expand into tuberous roots. The growth of aboveground leaves and underground storage organs is almost synchronous, for example, the ratio of crown to root in early June is 1.466. The number of swollen tuberous roots is generally fixed before mid-July, which is 4- 10. The dry matter accumulation of tuberous roots is also relatively uniform. From the end of June to the end of September, the fresh-dry ratio of root tuber was between 5 and 5.8, which changed little, which was beneficial to the accumulation of dry matter, indicating that the growth of seedlings had great advantages. No matter the leaf color, the number of leaves, the size of leaves and the number of hairs on the leaves, the smoothness of the upper leaves in Miao Di is different and varied. The underground root is the same as the aboveground root. Some plants can grow large and concentrated spindle-shaped tuberous roots, while others are rod-shaped or spherical. Some thin roots (commonly known as halters) are very long, while others are very short. The color of the root tuber is also light yellow, light yellow, orange, red and so on. Even the root tuber of the same plant has different colors and halters of different lengths. These differences are the basis of cultivating improved varieties. Therefore, the yield of field seedlings depends on the proportion of long-rooted seedlings, that is, on the heredity of seeds. The heritability of each batch of seeds is different, so the yield of seedlings with roots is also different, which is why seeds are not used for reproduction in production. In spring, 2-5% of seedlings can blossom and bear fruit, but most of them will not blossom until the next year. The seedlings bred in June-July can grow tender and uniform roots after transplanting, which do not bloom in that year and wither in winter. In the second year, they can be used as breeding seeds, and 100% can blossom and blossom without replanting.

3. Growth and development of clones

Compared with seedlings, the growth of control plants is obviously weakened, for example, it takes 25 days to emerge after planting, and the emergence rate is only 60-80%, so the field population is not as strong as seedlings. The flowering rate of that year was about 6%, which had a great relationship with varieties. From the ratio of crown to root, it can be seen that in the early stage of growth, the aboveground part is dominant, and the growth rate of underground part is slower than that of aboveground part. When there is a certain leaf area, the growth of aboveground parts gradually slows down or stops, while the growth of underground parts increases rapidly, so the ratio of crown to root is always greater than 1. With the extension of the growth period, the ratio of crown to root gradually decreased, and the ratio of root to shoot increased, and finally the aboveground and underground parts stopped growing. For a long time, vegetative growth dominated asexual reproduction, and it was not until August 30th that the growth of underground storage organs surpassed that of aboveground vegetative growth, that is, the aboveground growth reached its peak later and kept constant for a short time, but withered faster, shortening the time of dry matter accumulation and reducing the yield. The number of expandable tuberous roots is 3-4, and the halter is generally longer. But asexual propagation, if the variety is pure, the shape of the aboveground part is neat, the color, shape and weight of the root tuber are uniform, and the yield is stable, so pure asexual propagation lines are often used in production. The big roots are easy to rot during the winter, bolting and flowering in the next spring, and the old roots become chaff.

If the seedlings are propagated asexually for the first time (F 1 asexual propagation), we can still see the growth advantages similar to the seedlings, such as high emergence rate, fluctuation of leaves and growth speed of the roots, which are often between the seedlings and the control. The number of expandable tuberous roots per plant is less than that of seedlings, but the difference is not significant. The flowering rate was higher that year, reaching 34%.

The comparison of F 1 asexual propagation and long-term asexual propagation, the survival rate of seedlings in the field, the ratio of root to shoot above ground and underground, etc. (Figures 14-74, 75 and 76).

Fig.14-74 leaf area growth dynamics of rehmannia glutinosa under different propagation methods and sowing dates and its relationship with meteorological conditions.

Fig.14-75 growth dynamics of underground parts of Rehmannia glutinosa under different propagation methods and sowing dates and its relationship with meteorological conditions.

Fig. 14—76 Comparison of growth dynamics of aboveground and underground parts of Rehmannia glutinosa under different propagation methods and sowing dates 4. Growth and development of inverted plants.

It was planted upside down in mid-July, and the seedlings grew slowly from the end of July to the beginning of August. By September, the plant width will reach15-20cm, and each plant can grow 3- 10 tubers with a diameter of1-2.5cm, which is suitable for planting in the next spring. The overground part of first frost naturally withered and overwintered. No flowers in that year, but flowers in the next spring 100%. In early spring, the root tuber is full and tender, and germinates well as a seed. After the seeds mature (June), the tuberous roots turn dark gray and germinate badly. After August, new roots can grow, but the number is small and small. Moreover, after some seeds fall to the ground, the seedlings grow similar to the wild type, and their small tubers are easily mixed with the tubers of inverted varieties, leading to degradation.

5. Growth and development of different varieties

The growth and development of each variety is different, such as Little Black Hawk, Beijing 1, Beijing No.2 and so on. And older varieties such as Golden Champion, New Champion, Xinggoda, etc. There were big leaves and small roots before August, and they began to swell rapidly after September of the following year in August. The former overwintering seedlings can blossom and bear fruit in large quantities, while the latter, especially the gold champions, seldom blossom and bear fruit. These characteristics are worthy of attention in cultivation and breeding.

(2) Requirements of Rehmannia glutinosa on environmental conditions

1. temperature

At the temperature of 22-30℃, the seeds of Rehmannia glutinosa have enough humidity and germinate 3-5 days after sowing, but most of them do not germinate at 8℃. The germination temperature of root tuber is 18-2 1℃, the appropriate humidity is 10-20 days, and it takes 30-45 days at 1 13℃, but it does not germinate below 8℃ and is easy to rot. New shoots grow rapidly at 25-35℃, slowly below 25℃, and stop growing below 15-20℃. The leaves turn yellow and red at about 10℃ and wither at about 0℃. The tuberous root begins to swell and grow at 20-25℃, grows rapidly at 25-28℃, and hardly grows below 15℃. Tuberous roots grow well in high temperature and drought, and rot easily in high temperature and high humidity. The flowering rate of plants wintering at low temperature is very high. In early spring, the flower buds can bloom at 10-20℃, and when the capsules and seeds mature, the temperature is 25-28℃. Therefore, the growth of Rehmannia glutinosa needs higher temperature and is also cold-tolerant.

2. Humidity

When the soil moisture content is 20-34%, the seeds germinate, and the soil moisture content of 0-5 cm is 8- 12%, and the root tuber can germinate. The moisture content is lower than 8%, which affects the emergence of seedlings. The soil water content in the growing period is about 12%. Drug farmers often take "soil moisture yellowing" (that is, soil moisture content makes soil yellow) as the appropriate. During the peak period of root swelling from August to September, keeping the soil moderately moist is helpful for high yield. However, the soil is too wet and the root system does not grow well. In the hot and humid season, after the rainstorm, the roots seem to be in warm soup, which often leads to leaf blight and stem rot, and the aboveground parts die. If water is accumulated for 2-3 hours, it will often lead to root rot and plant death. The suitable relative humidity of air in the growth period is 50-80%, which is too wet and leaves are tender and not resistant to diseases. The overwintering soil is too wet, and the root tuber is easy to rot. In the spring flowering and fruiting season, soil moisture is conducive to flowering and fruiting.

lamplight

Rehmannia glutinosa mostly grows in sunny and dry places. The whole growth period needs enough sunshine, and the leaves are yellow, weak and thin, which is easy to get sick. In the hot and humid season, after a few days of rain, the leaves turn light green, which is easy to get sick. Suddenly, the sun is shining, and the plants can't stand it, and the leaves are dry forever. If there are trees or buildings blocking the sunlight, the plants will turn yellow and weaken, and the roots will not grow well. Sufficient sunshine, less rainy days, strong plant growth, strong disease resistance, high yield and full seeds. Seed germination needs light. Under dark conditions, they will not germinate even if the temperature and humidity are appropriate.

4. Soil and fertilizer

Rehmannia likes neutral or slightly alkaline loose and fertile sandy loam, binary soil and fertile clay. Rehmannia glutinosa can also be planted. Although its emergence is slow, its yield is high, and Rehmannia glutinosa is more suitable for its growth. Rehmannia glutinosa likes fertilizer, and the soil with sufficient base fertilizer or fertile soil has good root tuber and high yield, but the root tuber is small because of insufficient fertilizer. Fertilizer-loving varieties have more obvious response to fertilizer. Sufficient fertilizer is needed before the leaves stop growing. If too much effective nitrogen fertilizer is applied after the leaves stop growing, the leaves will often grow in vain, thus affecting the root growth. Organic nitrogen, phosphorus and potassium fertilizer are more suitable for the growth of rehmannia glutinosa, and adding phosphate fertilizer to the base fertilizer is beneficial to the growth of rehmannia glutinosa root system. Adding plant ash or potassium fertilizer to potassium-deficient soil is also beneficial to root growth. Because of the short growth period, it is suitable to apply quick-acting organic fertilizer bean cake.

5. Air and biology

The growth environment is not ventilated, plants are prone to diseases, and poor permeability of root soil will cause rotten roots. The fibrous root on the root tuber is easy to be infected with cyst nematode, which makes the overground part grow yellow and weak, and the root tuber cannot expand. In particular, the gold champion variety is the most susceptible to nematode infection, and continuous cropping also makes Rehmannia glutinosa grow yellow and weak, which is very susceptible to diseases.

Third, cultivation techniques.

(1) Variety

Rehmannia glutinosa has a long history of cultivation and many local varieties. There are many varieties cultivated, such as gold champion, new champion, little black English and so on. In addition, White Champion, Sweet Potato King, Xing Gea, Guo Li Cat, Four-toothed Hair, Daqingying, etc. also have a certain cultivation area. In recent years, new varieties Beijing 1 and Beijing No.2 bred by artificial hybridization have been cultivated in large areas in Henan, Shanxi, Shandong, Hebei, Inner Mongolia and other places, and 1, a virus-free gold champion variety, Stem Tip 16 has also been applied in production. The main cultivated varieties are introduced as follows: