I. Morphological characteristics
The plant height is about 60cm. Taproot is fat, multi-branched and fleshy; The rhizome is short and erect, growing a node every year, commonly known as "reed head". Its shape is horse tooth (horse tooth reed), bamboo joint (bamboo joint reed) or cylindrical (round reed), with terminal overwintering buds and lateral adventitious roots. The taproot is stout, fleshy, cylindrical, oblique, with branches at the lower part and yellow skin; Long fibrous roots and many warts. Stems erect, solitary and unbranched. Palmately compound leaves, verticillate stems with long stalks; There is one trifoliate compound leaf in one year, one trifoliate compound leaf in two years, two trifoliate compound leaves in three years, and one compound leaf will be added every year, with a maximum of six compound leaves. A pair of lobules are smaller on both sides, larger in the middle, ovoid, oblong or slightly obovate, 4- 15 cm long and 2-6.5 cm wide, with tapering tips, wedge-shaped downward extension at the base, serrated edges, green or yellowish green at the top, sparse veins and smooth at the bottom. Umbellies are solitary and terminal, and the total pedicel length can reach 30cm. Flowers are small and many; Calyx 5-lobed; Petals 5, yellow green; Stamens 5; Pistil 1, ovary inferior, 2-loculed, upper part of style 2-lobed; The disc is annular. The fruit is berry-shaped, flat kidney-shaped, bright red when mature, and a few are yellow or orange. Contains 2 seeds. Seeds kidney-shaped, yellowish white or grayish white. The number of chromosomes is n=24, and the karyotype formula is 2n=22M+22SM+4ST (figure14-1).
Fig.14 ——1ginseng morphological diagram.
1. Plant 2. root
Second, biological characteristics.
(a) the growth period and the whole growth period
The growth period of ginseng can be divided into seedling stage, leaf spreading stage, flowering stage, fruiting stage and withering stage. One-and two-year-old ginseng has no flowering period and fruit period. The growth period of ginseng is closely related to its length, geographical location, climate change and cultivation conditions. The main producing area of ginseng in Northeast China is located in the middle temperate zone, and the seedling stage is generally in early and middle May. The leaf exhibition period is from late May to early June; The flowering period is in the first half of June; The fruiting period is in the middle and late July; The withering period is at the end of September of 10/early of October. The whole growth period is generally 130- 150 days, from 100- 1 10 days to 180 days or more. The higher the latitude in the middle temperate zone to the north, the shorter the whole growth period and the corresponding delay in emergence; The lower the mid-temperate zone to the south latitude, the longer the whole growth period and the earlier the seedling stage. At the same latitude, with the increase of altitude, the whole growth period is shortened and the emergence stage is delayed accordingly.
(2) Growth and development
1. Underground organ
(1) root
After autumn sowing or spring sowing, mature seeds sprout radicles into the soil in the middle and late April to form young taproots, and then young branch roots grow on the young taproots. Young taproot and young branch root are mainly translucent with water, and then gradually cork. May-June is the jointing stage of taproot, and then the taproot growth period is vigorous. The root length can reach 5 cm, and 20-30 young branch roots grow. In early June, the upper part of young taproots gradually became cork, and in early July, white taproots formed. At the beginning of August, the young branch roots began to be corked, most of them lost water and fell off, and a few became white branch roots. When taproot and branch root are corked, some root hairs of fibrous roots are renewed with epidermis shedding.
From the second year, the taproots and lateral roots became thicker and the fibrous roots developed, forming basic roots. Since then, with the increase of years, the root system of ginseng has developed, elongated, thickened and gained weight year by year, forming a balanced and complete root system with main branches and fibrous roots. Six-year-old ginseng root, the main root length can reach more than 6cm and the diameter can reach more than 2cm. Generally, there are 2-3 branched roots and dozens of fibrous roots, and the total length of roots can reach about 35cm. Generally, the average fresh weight of a single root is about 50-80g, and some of them are above 300g. According to the determination, the annual growth of four to six-year-old ginseng roots generally increases with the increase of annual growth (table14-1).
Table14 ——1Annual growth of two to six-year-old ginseng roots
According to the research, the growth process of perennial ginseng changes in an S-shaped curve within one year (Figure 14-2). After the emergence of ginseng, the aboveground organs began to grow, mainly consuming the nutrients stored in the roots, and the root weight gradually decreased, and the root weight decreased to the lowest value from 20 to 25 days after the emergence of ginseng. At this stage, special attention should be paid to raising the soil temperature in the border, avoiding excessive soil moisture, promoting seedling emergence and preventing root rot. Ginseng entered the flowering stage, and the aboveground and underground parts entered the vigorous growth stage at the same time. The weight gain of ginseng roots increased linearly, reaching the highest value at 126 ~ 130 days after emergence, that is, before ginseng withered. During this period, special attention should be paid to light adjustment, water supply and fertilization, and field management should be strengthened to meet the demand of ginseng growth for light, water and fertilizer. After the aerial part of ginseng withered, the root of ginseng no longer gained weight, but gradually lost weight due to respiratory consumption.
Fig.14-2 root growth curve of four to six-year-old ginseng.
(Ding Xiquan et al., 1985)
The growth rate of ginseng roots is different in each period during the growth of a year. According to the measurement, the growth rate of four-to six-year-old ginseng roots showed a single-peak curve, and the peak appeared in 2-2.5 months after emergence (figure 14-3), while the growth rate of ginseng roots was basically close to the maximum growth rate within 40 days before and after the peak. During this period, effective cultivation and management measures should be taken as far as possible to ensure the healthy growth of ginseng and improve photosynthetic efficiency.
Fig.14-3 root growth rate curve of 4-6 years old ginseng
(Ding Xiquan et al., 1985)
The root of ginseng belongs to downward contraction type, or contraction root. The taproot shrinks every year, and the rhizome is pulled down as long as 1, so that the overwintering buds at the end of the rhizome are often hidden in the soil.
Therefore, the life form of ginseng belongs to underground bud plants. Because the taproot has the characteristics of downward contraction, annular stripes are produced on the taproot, which increase with age. Shrinkage starts from the upper part of the taproot, increases with age, and gradually extends to the middle and lower part of the taproot. Therefore, the older the ginseng is, the finer and deeper the lines are, and most of them are spiral lines.
(2) Rootstock
Or underground stem, inserted at the end of the taproot, is the hub connecting the taproot with the above-ground organs. There are overwintering buds on the rhizomes, and the aboveground branches are drawn out every spring, and wither in autumn, leaving stem marks. The number of stem scars is an important basis for judging the growth period of ginseng. The outer edge of each stem scar has a latent bud process. When the main root system is unfavorable or susceptible to diseases, rhizomes can generally grow 1-5 adventitious roots, which play a role in absorbing and storing nutrients by the main root system. The size and shape of rhizome are closely related to the age of ginseng, the penetration and direction of taproot, the growth environment and cultivation conditions. Rhizomes are usually owned by perennial plants; The formation of rhizome is an adaptation to overwintering and other unfavorable environments. Rootstock is not only an organ for vegetative reproduction and renewal of ginseng, but also a place for storing nutrients.
(3) overwintering buds
Except for the one-year-old seedlings germinated by seeds, ginseng plants (aboveground branches) for more than two years all grew and developed from overwintering buds. The overwintering buds attached to the end of the rhizome are covered with three layers of white bud scales. There is a fully differentiated bud primordium in the axil of bud scale. When the temperature is suitable in spring, the overwintering buds begin to germinate, and complete aboveground branches can grow in about 8- 10 days. In the leaf axils of scales, there is a small conical protrusion at the base of both sides of the differentiated main bud. One is the precursor of overwintering buds (larger, close to stem scars). After the overground branches were extracted in spring, they began to differentiate in June, and then increased to the middle and late July, forming overwintering buds before winter, and the overground branches were extracted in the next spring. The other is the protoplast of dormant buds, which is composed of a small group of meristems and rarely differentiates, and its position is opposite to the former. The overwintering buds are located at the base of the stem when they are extracted from the aboveground branches in spring; When the aboveground branches wither in autumn, they stay at the edge of stem marks and are in a dormant state. This dormant primitive bud leaves a stem scar every year. If the overwintering buds are damaged in winter and spring for some reason, the overground branches cannot germinate and grow in this year, and then new overwintering buds will be formed from the overwintering buds, and overground branches will grow in the third year after overwintering. If not only the overwintering bud is damaged, but also the overwintering bud primordium and dormant bud primordium differentiate to form overwintering bud. If the whole overwintering bud is damaged (including overwintering bud and dormant bud primordium), several new overwintering buds will be developed from stem scar dormant bud primordium in the last year or longer, and 1-3 or more aboveground branches will be taken out in the spring of the following year. Using this principle, the formation of multi-stem ginseng can be promoted by artificial germination.
The development of overwintering bud primordium into normal overwintering bud, that is, overwintering bud that can germinate at suitable temperature, must go through the following two stages.
The first stage is high temperature stage or morphological post-ripening stage, the temperature is 18-20℃, and the time is about 4-5 months, which is slightly consistent with the natural conditions in summer. At this stage, the overwintering bud primordium develops into overwintering bud with stem, leaf and inflorescence primordium.
The second stage is a low temperature stage or a physiological post-ripening stage, which requires a temperature of 2-3℃ and a time of 4 months. After the overwintering buds are differentiated and formed, they must go through the low-temperature post-ripening stage to germinate and emerge.
The overwintering buds without low temperature period were soaked in 100ppm gibberellin solution for 12 hours, which could replace the low temperature effect, promote after-ripening and emerge early. It usually appears about 20-30 days after treatment.
2. Above-ground organs (
1) stems are the main vegetative organs that transport and support the aerial parts of ginseng. The stems of ginseng are extracted every spring and die in autumn. Annual stems (actually petioles) are issued by seeds; From the beginning of two years, it is all issued by overwintering buds. Ginseng is generally single-stemmed, and rarely has two, three or four stems. It is generally believed that the number of stems is related to heredity, climate, soil quality, year, cultivation area and conditions; In areas with heavy rainfall, it is easy to produce many stems. Artificial germination can promote the formation of multiple stems. The stems of ginseng will thicken with age.
(2) Leaves
It is an important vegetative organ of ginseng for photosynthesis, gas exchange and transpiration. With the increase of age, the number of leaves increases and the leaf area increases. But in the same year, different plants or different cultivation areas have different degrees of leaf development. Generally, the annual leaf area is10-30cm 2; By the age of five or six, it can generally reach about 1500cm2. It grows slower and smaller than ordinary crops.
Ginseng is a negative plant and is not resistant to strong light. When the light is too strong, it will show obvious adaptation and growth inhibition in the growth characteristics such as leaf phase, leaf size and leaf color. When the light intensity reaches 60klx or 50klx and lasts for a long time, the leaves stand upright (that is, the angle of leaf extension becomes smaller), the leaves curl (the two halves of the leaves roll up along the midvein), and the whole plant inclines to the light (the direction and angle of inclination are slightly consistent with the direction of the sun under the maximum direct light), and the leaves are pale. This can avoid absorbing too much solar energy, thus reducing leaf transpiration or preventing leaf temperature from rising sharply and avoiding injury. If the strong light irradiation time is too long, when the leaf temperature reaches 30-33℃, the leaf will burn (commonly known as sunburn), wither and fall off. Therefore, ginseng must be cultivated in shade shed. Growth inhibition is characterized by shorter stem height and smaller leaves (Table 14-2).
Table 14-2 Effects of Different Light Conditions on Growth Characteristics and Chlorophyll Content of Ginseng Plants
With the increase of light intensity, the leaves change from dark green or green to light green or yellow-green, and the chlorophyll content in the leaves is obviously reduced to reduce the absorption of light and avoid overheating and burns (Table 14-2).
When ginseng emerges in spring, the leaves are small and shriveled, and then gradually expand, and the leaf area expands rapidly within one month (from early June to early July) after the leaves are expanded, and then rarely expand; The number of blades is fixed and will not increase.
(3) Flowers
It is an important reproductive organ of ginseng. The flower buds of ginseng are formed during the differentiation of overwintering buds. Generally, flowers bloom once every three years and rarely once every two years. The florets of umbels increase with age, from a dozen to dozens.
When ginseng blooms, the outer edge of the inflorescence opens first, and then opens to the center one after another. The flowering days of each inflorescence vary from 5 days to 15 days, usually 8- 10 days. The opening time of each flower is 23-48 hours in sunny days; It takes 30-60 hours on rainy days. In a day, the flowering frequency is the highest with 7- 13. Weather conditions have a great influence on flowering. There are many flowers in hot sunny days; There are few flowers at low temperature in rainy days. Generally, flowers bloom most when the temperature is 17-20℃ and the relative humidity is 40-45%.
Ginseng belongs to cross-pollinated plants. On the one hand, cross-pollination is beneficial to prevent variety degradation, but on the other hand, effective measures should be taken to prevent cross-pollination in the breeding and breeding of improved varieties so as not to affect the purity of varieties.
(4) Fruit
When the ginseng fruit matures, the inner layer of the ovary wall lignifies, forming a hard endocarp; The outer layer of the ovary wall becomes fleshy red flesh. Each fruit contains two seeds. Five-year-old ginseng can harvest 4-5g fruits per plant; The seed rate (dry weight) of fruit is about 20-25%.
(5) seeds
Ginseng seeds belong to the type of incomplete embryonic structure development. The embryo of newly harvested seeds is very small, consisting of only a few embryonic cells, with a length of about 0.3-0.4 mm, a width of about 0.25mm and an embryo area of about 0.075mm2. The endosperm is about 5-6 mm long and 4 mm wide, and its area is 266 times that of the embryo. The embryo is locked or half-moon shaped and located in the endosperm cavity. Therefore, ginseng seeds can only germinate and emerge after ripening. The ripening process can be divided into two stages: morphological ripening and physiological ripening. In the morphological post-ripening stage of embryos, primitive cells gradually differentiate and increase under suitable conditions of water, temperature and oxygen. When the embryo length 1.0- 1.3 mm, the seeds began to crack, and when the embryo length was 3.0-4.5 mm, it differentiated into an embryo with cotyledons, embryos, hypocotyls and radicles, and the morphological post-ripening stage was basically completed (Figure 65438
Figure 14-4 Introduction of Ginseng Seeds
1. Newly harvested ginseng seeds 2. Mature ginseng seeds after morphological completion.
After the morphological ripening of ginseng seeds, it does not germinate even under suitable germination conditions, and it must go through the physiological ripening period at low temperature. There is no morphological change at this stage, only the embryo body increases.
The morphological post-ripening period of ginseng embryo needs 3-4 months 18- 12℃ temperature change. The physiological post-ripening period needs a low temperature of 2-4℃ for 2-3 months. The post-ripening process of seeds is strictly sequential, and if the early stage is not completed, the later stage cannot be carried out; Seeds that are not fully mature cannot germinate. After maturity, when the embryo length is generally 5.0-5.5 mm, or the embryo rate (embryo length/endosperm length × 100) reaches 100%, the seeds germinate and emerge at a suitable temperature.
During the post-ripening process of ginseng seeds, a series of physiological and biochemical changes occurred in the seeds. The activities of glycolytic enzymes, protein hydrolase and peroxidase were low in the early stage of embryo morphological post-ripening, and gradually increased with the growth of embryo. When the embryo enters the physiological post-ripening stage, the activities of various enzymes are significantly improved, and cytochrome oxidase appears in the endosperm and embryo, concentrated in the root tip.
The application of growth regulators can promote the post-ripening of ginseng embryos and break dormancy. According to Zhu Guixiang, soaking ginseng seeds with 40ppm gibberellin for 36 hours before germination treatment can shorten the germination time by at least 30-40 days. According to the research, soaking seeds with gibberellin 50ppm or 12 ppm for 24 hours or 100 hours, with kinetin 50ppm or 75ppm for 96 hours, with 100 ppm for 24 hours, can replace low temperature, promote physiological after-ripening of embryos, and shorten the time by half.
(3) Photosynthetic characteristics
Ginseng belongs to C3 plant. The results showed that the δ 13C of ginseng was-26.80; PEPCase activity was14.33μ/mg portmim; The CO2 compensation point is 80-102ppm; The maximum photosynthetic rate was10.81/mgco2/dm2h; The leaves of C4 plants have no typical morphological and anatomical features. The diurnal variation of photosynthesis shows that the photosynthetic rate of ginseng is the highest from 9 am to 6 pm in a day. The annual change of photosynthesis, the average daily photosynthetic rate of ginseng in flowering and green fruit period is the highest in a year. The annual total photosynthetic rate, annual economic photosynthetic rate and PE/PT(%) of four-year-old and five-year-old ginseng were the highest. There is no obvious correlation between the leaf area of ginseng and the annual growth of ginseng roots, so the planting of ginseng should have reasonable density and make full use of light energy.
(4) Environmental requirements
1. light
Ginseng is a negative plant and requires strict light. The intensity of light directly affects the development, yield and quality of ginseng. The light compensation point of ginseng is about 400lx, from 400lx to 10klx, the photosynthetic rate of ginseng seems to increase linearly from 10klx to 33klx, and the photosynthetic rate of ginseng increases slowly (Figure 14-5).
Figure 14-5 Photosynthetic Intensity of Ginseng under Different Light Intensity
(Wang Tiesheng, 1983)
The optimum light intensity for ginseng growth generally increases with the increase of latitude. The low latitude area is 7-10 klx; 10-22klx at high latitudes. Under the same latitude or geographical and ecological conditions, different years and growing seasons need different optimal light intensity.
2. Temperature
Ginseng is a temperate plant. Like warm or cold climate, it can be cultivated under the climatic conditions of annual average temperature of 2.4- 13.9℃, accumulated temperature ≥101800-3,800℃ and annual rainfall of 500-2,000mm ... In the subtropical mountainous area with low latitude and high altitude, the medicinal materials field of Le Tong Brigade, Ziyuan County, Guangxi Province, East longitude110 38', altitude 1450m, annual average temperature 13. 1℃), Jiuxian Mountain, Daiyun Mountain, Dehua County, Fujian Province (25 43' north latitude,1℃)
The optimum temperature for ginseng seed germination is12-15℃. The lowest temperature is 4-6℃; The maximum temperature is 30℃. Different growth stages of ginseng need different temperatures (Table 14-3). When ginseng comes out of seedling stage, the temperature is high and rises quickly, which is beneficial to seedling emergence. The temperature is low and the leaf spreading lasts for a long time. When the temperature is lower than 15℃, it seldom blooms, and when it is over 25℃, the flowering rate decreases.
Table 14-3 Temperature Requirements of Ginseng in Different Growth Stages
Too high or too low temperature during the growth period will have adverse effects on the growth and photosynthetic organs of ginseng. Summer is hot and dry, and stems and leaves are prone to sunburn or wilting and death. Ginseng has certain resistance to light frost (temperature -3℃); Severe frost at MINUS 5 degrees will cause freezing damage. During the hibernation period of ginseng, due to improper cold protection and sudden change of soil temperature, the overwintering buds will be frozen, commonly known as slow yang freezing. Before and after freezing injury, overwintering buds are affected by drought, wet injury, bacterial infection, mechanical injury and soil suffocation, which will promote or aggravate freezing injury. Therefore, the occurrence of freezing injury can be avoided or alleviated by doing a good job in overwintering and overwintering management and taking other effective measures such as drought resistance, drainage, wind prevention, soil disinfection and planting high-quality ginseng seedlings.
Step 3: Moisture
Water is one of the basic conditions for ginseng to survive, and it is also an important condition and medium for using light, heat, nutrients, air and other living conditions. Grasping the physiological and ecological water demand law of ginseng and meeting the balance between supply and demand of water metabolism in its life cycle is the premise of obtaining high yield and high quality of ginseng.
Water is the primary condition to accelerate the germination and post-ripening of ginseng seeds. The water absorption of ginseng seeds is 30-50% of the seed weight, so it should be fully absorbed before germination. The humidity of the sand storehouse in the post-ripening stage of seeds is 10-24%. Insufficient water absorption of seeds affects the process of accelerating germination; Too much water affects seed respiration, leading to seed rot.
The water requirement of ginseng is different in different growth stages and years. In the stage of emergence and leaf development, the temperature is low, the transpiration intensity of leaf surface is weak, and the water demand is not much; After leaf spreading, the temperature rises, the leaf area increases rapidly, the root system continues to elongate (June-July) and thicken (July-September), and the physiological and ecological water demand increases. Different soil moisture during the growth period has certain influence on the growth of ginseng plants. Appropriate water ratio is beneficial to leaf growth, leaf area and leaf width under the condition of insufficient water (below 60%) or excessive humidity (100%).
Soil moisture during growing period has an important influence on the accumulation of dry matter of ginseng. The relative water content of soil is above 80%, which is beneficial to the growth and weight gain of ginseng roots, with fast dry matter accumulation, high biological yield and large economic coefficient. When the relative soil water content reaches 100% or 60-80% in the whole growth period or middle stage, it also has adverse effects on the dry matter accumulation of ginseng. The relative water content of soil is 40-60%, which will seriously affect the weight gain and even reduce the yield of ginseng roots. It shows that ginseng is a plant that is afraid of drying. The relative water content of soil in the whole growth period is 80%, and the highest photosynthetic rate of ginseng is 4.3 Co2mg/dm2 h, which is beneficial to dry matter accumulation.
In a word, ginseng is an arboreal negative plant, which is neither drought tolerant nor waterlogging tolerant. Under the condition of soil relative water content of 80% in the whole growth period, ginseng grows healthily, with high photosynthetic rate and rapid weight gain of ginseng roots, achieving high yield and high quality; When the soil moisture is insufficient (60%), the roots of ginseng often appear burning whiskers; When the soil moisture is too high (100%), ginseng roots are easy to rot. Therefore, soil moisture disorder is an important reason for ginseng yield reduction. When the soil moisture is too high during dormancy, freezing injury often occurs. With the annual growth of ginseng, the water demand increases and the drought resistance increases. When the soil is dry, the root system of ginseng is stunted, from "burning beard" to wilting and death.
According to the measurement, the transpiration intensity of ginseng is 6.25 g/h m2, the transpiration coefficient is 168, and the transpiration efficiency is 6. The total water demand in the whole growth period is 135kg/m2. See figure 14-6 and table 14-4 for the water evapotranspiration and water demand modulus coefficient of ginseng at different growth stages. The daily water demand and water demand modulus coefficient of ginseng are important basis for formulating irrigation system and rational water use. The daily evapotranspiration of ginseng is the largest at seedling stage and flowering stage, so it is very important to meet the physiological and ecological water demand of ginseng at this stage.
Fig. 14-6 daily evapotranspiration of ginseng in different growth stages
(Wang Tiesheng et al., 1987)
Table 14-4 modulus coefficient of ginseng water demand
4. Mineral nutrition
The leaf area of ginseng is limited, and the average leaf area of a plant growing for 2 years is 0.59dm2；; The growth in 4 years is 5.48dm2；; 13.64 dm2； After six years of growth; The photosynthetic rate is low, generally 6-9 CO2 mg/dm2 h. The growth is slow, and the average annual weight gain of cultivated ginseng is 6-9g. The wild ginseng is only1-1.5g, and the highest is 3g. Therefore, the demand of ginseng for mineral nutrition is lower than that of common cultivated crops. Compared with carbon, mineral elements account for only a small proportion in ginseng, but they are an important basis for building ginseng body and active physiological functions. According to Yu Derong, ginseng plants contain 27 kinds of inorganic elements, among which the average content of Ca, K, S, N and Mg exceeds 1000ppm. The average content of phosphorus, sodium, iron and A 1 is greater than100-1000 ppm; The average content of zinc, barium, strontium and manganese is greater than10-100 ppm. The average content of boron, titanium, copper, chromium, arsenic and tin is greater than1-10 ppm. The rest < < 1ppm are lead, nickel, vanadium, lithium, molybdenum, cobalt, lanthanum and gadolinium (table 14-5). It can be seen that the absorption rate of ginseng to three elements is about n ∶ p ∶ k = 2 ∶1∶ 4.4; The absorption of calcium by ginseng is about 1.4 times that of potassium; The contents of calcium, sulfur, magnesium, iron, aluminum, zinc, barium, manganese and boron in the aerial parts of ginseng are high. However, the contents of nitrogen and phosphorus in roots are high. These can be used as theoretical and technical basis for scientific fertilization of ginseng.
Table 14-5 Inorganic Elements in Ginseng Plants (unit: ppm)
【 Note 】 Take 10 plants on average and repeat twice. Automatic nitrogen analyzer.
5.pH
Ginseng likes slightly acidic soil, and pH 4.5-5.8 is the most suitable for ginseng growth, and above pH 4.5 is unfavorable for ginseng growth.
Third, cultivation techniques.
(1) variety
Ginseng cultivation in China has a long history, but so far there are no varieties artificially created by breeding departments through various breeding methods according to scientific methods. Northeast China is the main producing area of ginseng in China. Under the natural and production conditions of the producing area, after long-term artificial selection and natural selection, some so-called farm varieties or local varieties, such as Damaya, Ermaya, Long Neck and Round Reed, have been formed, which are mainly distinguished and named according to the morphological characteristics of roots. In addition, phenotypes of different genotypes can be found in production, such as "pprrhh" and "PPRRHH". According to the report of Jin Lan, there are obvious differences in morphological characteristics and total saponin content among four local varieties (Table 14-6). "Trojan tooth" has the advantages of fast growth, high yield and high content of total saponins. Followed by "Ermaya"; "Long-necked" and "Cirrus orbiculatus" have slow growth, low yield and low total saponin content. Some researchers have also reported that there is no significant difference in the total saponin content of the above four varieties. At present, ginseng cultivated in production is a complex mixed line. A survey of state-owned ginseng fields in six counties in the main producing areas by the Institute of Specialty Products of China Academy of Agricultural Sciences shows that the phenomenon of different varieties of ginseng is quite serious, in which Damaya accounts for 44.5% of the total output, Ermaya accounts for 40.0%, Longbo accounts for 8.8%, Yuanbang Lu Yuan accounts for 2.7% and the rest accounts for 4.0%. According to local ecological conditions and cultivation characteristics, the purified mixed population can be selected in ginseng producing areas, and local varieties with certain economic value, consistent heredity and suitable for local natural and production conditions can be selected for cultivation. According to the report of Sun Xian, huinan county, Jilin Province, has bred and purified the variety "Hemp Sub" from the seedling farm, and planted it in a large area, which has achieved remarkable results in increasing production and income. The yield 1.55kg/m2 of the 8500m2 improved seed field is 0.3kg/m2 higher than that of the general field, and the income 1.25kg/m2 is above.
Table 14-6 Morphological Characteristics of Different Ginseng Varieties
(2) Farming system
Ginseng cultivation system or method can be roughly divided into two types: one is direct seeding method, which does not transplant after sowing, and grows continuously for 4-6 years to harvest, with the interval between seedlings 1-2 times. This cultivation system saves the land for planting ginseng, shading materials and production labor, and the yield, quality and economic benefits of ginseng are not low. In Wangqingmen Township, Xinbin County, Liaoning Province, 1978, the yield per unit area of a five-year-old 700m2 direct-seeding field was 2kg, and foreign ginseng accounted for 76%, which was 70% higher than that of the transplanted field, 20% higher and 73% lower in cost. It is the future development direction. Both Japan and South Korea have applied. American and Canadian American ginseng is cultivated by direct seeding. The second method is transplanting, matching nursery and Honda. After sowing, transplant 1 time during the cultivation period, such as "1, 5" (