First, the influence of temperature on Gastrodia growth The effect of temperature on Gastrodia growth: temperature is the main factor affecting Gastrodia growth. Gastrodia likes to grow in cooler summers and less severe winters. The longer the suitable temperature for the growth, the better the growth of Gastrodia. (I) Effects of temperature on asexual reproduction of Gastrodia elata Underground tubers begin to grow at a temperature of about 14°C in the ground temperature, and grow faster at 20-25°C and are inhibited at 30°C. The total accumulated temperature in the whole growing season within a year is about 3800°C. At an altitude of about 1,000 meters, it is most suitable for the growth of Gastrodia and Armillaria. When introducing gastrodia at low altitude or in plain areas, the ground temperature should be kept below 25°C. The soil temperature in hot summer season continues to exceed 25°C, the growth of Armillaria mellea and Gastrodia elata is inhibited, which affects the yield of Gastrodia elata. At the same time, the continuous high temperature also promotes the process of the degenerative degradation of Gastrodia. Therefore, Tianma is cultivated in low-altitude areas, and the summer heat is high. Season, it should be to prevent the heat. Although Gastrodia is able to withstand cold, it has a certain limit and cannot suddenly cool or continue to be extremely cold. Different cold seasons occur, and the procedure for cold injury of Tianma is different. If the temperature suddenly drops in the early winter, it will cause cold damage to Tianma. With the arrival of the cold season, the temperature will gradually decline, and the young anaesthesia tissue will gradually age, and the water content in the stem cells will decrease. The increase of the cell fluid concentration reduces the freezing point of the plant and prevents the atrophy of the raw material and protein coagulation. After the cold-resistance exercise, the cold-resistance of the gastrodia elata is increased. The gastrodia elata is under the subzero temperature for a long time, and after a long period of low-temperature exercise, no observation is made. Frozen gastrodia. Gastrodia elata, which grows in the cold northeast region, has a certain resistance to low temperatures. For example, in Fusong County, Jilin Province, at an altitude of 774.2 meters, the average temperature in January is -15.7, and the minimum temperature is -34.7°C. Gastrodia distribution still exists, but these In the frozen environment, long-term thick snow cover must be covered. The soil temperature in the distribution layer of Tianma under the snow layer should not be lower than -5°C. Gastrodia can survive winters normally. If snow is removed, Tianma will suffer freezing injury. As Gastrodia in the phylogenetic process, in the winter long-term overwintering at low temperatures around 0 °C, the formation of the need for low temperature during winter, low temperature can break the dormancy, so when the low temperature conditions can not meet its requirements, after germination Buds are also weaker, even after they are planted. With 0 °C -2 °C low temperature treatment for 40 days before breaking the dormancy, continue to sprout growth. The test results of Shen Dongxia et al. showed that the day after the dormant tuber went into the dormancy period, it did not meet a certain low temperature, even if the germination conditions were appropriate, it would not germinate. Once the low temperature requirement is met, the tuber still does not germinate when there is no suitable temperature condition, and it can germinate when it encounters suitable germination conditions. This is the crux of the natural conditions of Tianma hibernation can be as long as a few months. Wan Huilan's test results show that white hemp and rice hemp need low temperature of 1-10 °C, 30-60 days to go through the dormancy phase. However, the size of the seedlings has different requirements for the time at low and low temperatures. The medium and large juniper will enter the reproductive growth stage, with a low temperature of 1-5°C and a treatment time of 50-60 days, and small white hemp and rice hemp Belonging to the vegetative growth stage, use 6-10 °C, 30-40 days to break the dormancy. (II) Effect of temperature on stem growth In Hanzhong, Shaanxi Province, when the local temperature rises above 10°C in spring, the arrowhead stalk starts to germinate, and when the soil temperature reaches 10°C at the temperature of 10cm in the beginning of May in the second half of April, the seedlings begin to emerge. In late May, By the beginning of June, when the temperature rose to 19.4°C-29.9°C, the seed matured from June 14 to the end of June, when the average temperature rose to 21.7°C-22.4°C. The temperature has increased from 15°C to 22°C for nearly 70 days. Gastrodia also needs nearly 70 days to complete the whole process from seedling emergence to seed maturity. And Beijing is 50 meters above sea level in the northwest suburbs. In late April, 10cm ground temperature was about 15°C when the arrowhead stem buds were unearthed, and the temperature rose to 22.9°C in the middle and late May. Gastrodia seed matured also lasted nearly 50 days. The length of the stem growth cycle and the temperature increase have a certain degree. Correlation. In the autumn, the stems of T. mongolicum differentiate and form into the reproductive growth period, and must also undergo a low-temperature stage to break the dormancy. The dormancy period of kenaf is longer than that of white hemp and rice hemp. If it cannot meet the requirement of low temperature, it cannot be bolted after planting, occasionally emerges, and the plant growth is not normal. The arrowhead should generally be stored at a low temperature of 3-5°C for 2.5 months before it can pass through the low temperature dormancy phase and be smoothly bolted for flowering and seeding. (C) Effect of Temperature on Seed Germination Gastrodia elata seeds can germinate between 15 and 28°C, but the optimum temperature for germination is 25-28°C. Seed germination is inhibited at above 30°C, positive value after sowing in June and July. In the hot zone of the producing area, the temperature of 20-25°C is suitable for the requirements of seed germination. Due to the geographical location of each place and the difference in climatic conditions, the maturation period of the seeds of the gastrodia elata is different and the sowing date is sooner or later. The growth rate of bulbs is also different. For example, Fubao Mountain, Lichuan City, Hubei Province has an altitude of 1,550 meters above sea level. Seeds mature in mid-late July and germinate in late August. The ground temperature has dropped to 13.2°C in mid-October and the original bulbs have stopped growing. -50 days, when sowing can receive Xiaomami, and Tianma Research Institute, 1050 meters above sea level in Ningqiang County, Shaanxi Province, after the seeds germinate, the protocorm growing season reaches 70-90 days, and the size of fingers can be obtained in the sowing year. White linen. The white and rice hemp that were harvested in the two places had large differences. In the new introduction area of ​​Tianma new plant in southern Shaanxi, June seed germination in June, and the germination season of gastrodia elata in late June to July, the ground temperature exceeds 30°C and the temperature is generally high. Therefore, cooling measures should be taken to increase the seed germination rate and protocorm Growth rate. Second, the impact of water on Gastrodia growth Water is the main component of Gastrodia tuber, Gastrodia general water content of about 80%, Zhuang Yi has proved that Gastrodia can absorb some of the inorganic salts and minerals from the soil, but these nutrients must be dissolved Water can be infiltrated into Gastrodia. In China, wild gastrodia grows from the northeast to south China. Generally, the annual rainfall in the distribution area of ​​Tianma is about 1000mm, and the relative humidity of air is 80-90%. Rainy and rainy weather are the main characteristics of the wild gastrodia distribution area. In the different growing seasons of Gastrodia, the requirements for water are different. In early April, the tubers began to sprout and did not require excessive soil moisture. As long as the soil was kept moist, the gastrodin could grow normally. If precipitation in the late winter and spring, soil drought, also affect the growth of Armillariella, lowering the germination rate of lateral buds of Tianma affects the yield of Tianma. From July to September, it is the vigorous growth of tuber stems, which requires a large amount of water supply, so it is within three and a half months from June to early September. The abundant rainfall is the key to ensure the high yield of Gastrodia elata. During the hot season in July and August, the temperature is high and the amount of evaporation is large. It will cause soil drought after a long time without rain, and it will lead to the death of young buds. Sowing the gastrodin in the forest, mildly droughty forests will play a stimulating role, especially in the sowing hole covered with a layer of leaves, can have a very good effect on maintaining soil moisture. However, in the case of serious drought, increasing the transpiration of trees, the soil in the forest is more arid than outside the forest, which will lead to the death of a large number of germinating protocorms. In the late growth phase of Gastrodia, especially in October, Tianma has already entered the hibernation period. The rainfall of many soil moisture is too high, which promotes the vigorous growth of Armillariella mellea. The Armillaria mellea will endanger Gastrodia and cause rot. Therefore, during the late growth period of Tianma, it is well established. Drainage is an important measure to ensure high yields. Therefore, in the field of poor drainage of white acre, in the summer after heavy rain should pay attention to do a good job of soil drainage to prevent gastrodiasis rot. Third, the impact of light on the growth of Gastrodia Gastrodia is a non-green plant, the underground stem growth from sowing to harvest, are carried out in the soil. Because of this characteristic, it can be cultivated in outdoor, indoor, air-raid shelters, underground tunnels, and in the absence of light. However, stems of Gastrodia elata have obvious phototaxis characteristics. After the ground stems are unearthed, strong direct light will harm the flower stems, and sunburn disease will cause phytoseiosis to die. Therefore, nursery gardens should be shaded. In August and August, during the peak season of Tianma, direct sunlight in the event of drought will increase the evaporation of soil moisture and affect the growth of tuber sprouts. Shade slopes and sunny slopes directly affect the distribution of light energy resources. Therefore, the cultivation of gastrodia in the cool high mountains, increased direct radiation can increase soil temperature, it should be selected Yangshan cultivation gastrodia. At the same time, the thickness of the soil can be reduced by increasing the temperature of the soil, or covered with a plastic film, and the storage of light energy can promote the growth of gastrodia. Introducing gastrodia in hot, low-lying mountains should be covered in summer to reduce the direct light irradiation and reduce soil temperature, so that Tianma can survive in midsummer. Fourth, the impact of soil on Gastrodia growth Gastrodia hi we grow in the loose loam soil, this kind of soil soil texture is more uniform, is a roughly equal amount of sand, clay and powder mixture, physical properties, good ventilation, water, A certain amount of water and fertilizer. Clay is poorly drained. When there is too much rain, the water will cause the death of gastrodia, and the poor permeability of the soil will also affect the growth of the alimentary fungus Armillariella and Gastrodia. In the Gastrodia elata production area, Gastrodia elata is cultivated in sandy soil, which grows faster and has more rainwater. The year's high yield, but the kind of soil water retention is poor, in case of drought, Gastrodia grow poor due to lack of water, less than loam soil yield stability. When there is too much rain, the yield of Gastrodia in the loam is often lower than that of sand. Fifth, the influence of topography and topography on the growth of Gastrodia elata distribution is closely related to climatic conditions. From the south to the north, the temperature gradually decreases, and the distribution of gastrodia elata at the same altitude gradually decreases. Gastrodia is a cool and humid environment. Summer temperatures in low mountain areas are too high, exceeding the limits required for the propagation of gastrodia and its accompanying bacteria, and also affecting the growth of gastrodia. Therefore, sporadic growth of Gastrodia elata is occasionally found in high mountains and low mountains. Not much, tubers are not large. Under artificial cultivation conditions, as long as the conditions needed for the growth of Gastrodia and Armillaria can be controlled, the summer high temperature and the winter low temperature can be controlled to create beneficial conditions for the growth and reproduction of Armillariella mellea, in the plain, low mountains or hot regions in the south. As well as the northeast cold regions can introduce test species Gastrodia. Yinshan and Yangshan have wild gastrodia distribution. When artificially cultivated, the mountain direction should be selected according to the local climate conditions. The difference in temperature on the yin and yang slopes is that the sunny slope is higher than the shady slope, and the difference between the foot and the mountain is greater than the mountainside. After the peak is reached, the difference disappears. When using the temperature difference of Yinyang Mountain, when planting Gastrodia, in the same area, the high mountain area has a low temperature and the growing season is short. Yangshan must be selected to plant Gastrodia; in low mountain areas, high temperature and low rainfall in summer should be used to select Yin Mountain with relatively low temperature and high humidity. Planted Tianma; and Zhongshan District should choose half-yin and half-yang. The wild Gastrodia elata at a slope of 5-10 degrees in gentle slopes or gullies is more widely distributed. The microclimate conditions and fertile deep humus in these areas are conducive to the growth of Gastrodia elata, thicker litter layers and moist Soils favored the suspension and germination of Armillaria spores and Gastrodia elata seeds. There is less distribution of gastrodia in the depths of the ridges and large forests. In artificial cultivation, places with certain slopes should also be selected, especially in areas with high rainfall, and the harm caused by poor drainage should be taken into account. China Agricultural Network Editor
