Cultivation method of red bean
Paclitaxel is an extract of Taxus chinensis in China, which has a unique anticancer mechanism. Dr. Broder, director of the National Cancer Institute of the United States, said that paclitaxel is a new anticancer drug with good efficacy and little side effects for many cancers after adriamycin and cisplatin in recent 15 years. Since 1980s, the United States, Britain, Russia, South Korea and China have conducted in-depth research. The United States took the lead in applying the research results to medical clinic and achieved remarkable clinical results in the treatment of various cancers. Since then, mankind has made new breakthroughs in the field of anti-cancer. So far and for a long time to come, the most favorable weapon for human beings to fight cancer can only be paclitaxel.
In addition to its important medicinal value, Taxus chinensis is a rare greening tree species with its unique appearance and green all year round.
In front of the United Nations Headquarters in new york; In front of Buckingham Palace, England; And the White House Square in America. We hope that the medicinal value of yew will not only benefit mankind, but also hope that in the near future, the beautiful and rich yew will make Beijing, which will host the 2008 Olympic Games, more beautiful.
At present, many domestic yew planting enterprises are developing yew series products. Such as Taxus bonsai, can be trimmed into umbrella, tower, circle and so on. Taxus health care cup, Taxus crafts, Taxus health care products, etc.
The State Forestry Administration has clear instructions on the current yew project: yew is a national first-class protected tree species with good ecological benefits and high economic value. The state supports the vigorous construction of Taxus chinensis forests within an appropriate scope, and encourages all sectors of society to participate in afforestation and greening in various forms such as contracting, leasing, auction and joint-stock cooperation. "
Compared with other countries in the world, China's yew resources account for more than half, but the world's demand for paclitaxel is far from enough. Since the US Food and Drug Administration (FAD) approved paclitaxel as a drug for the treatment of advanced cancer in 1992, the excessive logging of wild yew resources in China has become increasingly serious, and the wild yew resources have been seriously damaged. Moreover, many biological characteristics of wild yew restrict the development of natural communities. According to statistics, the annual incidence of cancer in the world is more than 654.38+million. If 0.006%-0.06% paclitaxel is extracted, it will consume 700-654.38+0000 tons of yew bark every year. Even if all the bark of yew in the world is collected completely, it can only maintain short-term needs. Moreover, the methods of synthetic or chemical taxol are still in the laboratory stage. Therefore, it is urgent to expand and develop Taxus resources artificially and establish a timber forest base for Taxus medicinal raw materials.
Several propagation methods of Taxus seedlings at present
1. Pre-propagation planting method
The preservation of Taxus resources and rapid propagation of seedlings are the basis to solve the problem of taxol timber forest construction, and the construction of large-scale Taxus plantation is the way to solve the problem of taxol raw materials. When raising seedlings with Taxus chinensis seeds, it is necessary to maintain the storage method of seeds, mix sand seeds or control the temperature, which has a good effect on budding after wintering and breaking the dormancy habit. Rub the seed coat before sowing, soak it in warm water and treat it with drugs and hormones. Shading after emergence is the key to raising seedlings? It can prevent the seedlings from being burned at high temperature, keep them moist and have a light transmittance of 40%. The emergence rate of Taxus cuspidata and Taxus cuspidata can reach 70-80%, and the emergence temperature should be higher than 65438 05 degrees.
The dynamic growth of seedlings is as follows: the plant height and stem diameter of seedlings grow slowly two years before emergence, and the plant height generally grows about 10CM in one year, and grows faster after transplanting for one year. In 3-5 years, the annual increase can reach 20-30CM.
2. Tissue culture and breeding of Taxus chinensis
Tissue culture makes use of the totipotency and clonality of plant cells. The tender stems, needles, bark, cambium, aril and embryo of Taxus plants are used as plants for cultivation and research.
(1). Fine varieties of Taxus cuspidata, such as fine organs of Taxus cuspidata (with high taxol content), were selected as explants, inoculated into culture medium, and a large number of tissue culture seedlings were obtained in the laboratory after callus formation, rooting and seedling formation. After substrate transplanting, seedling hardening and epidemic prevention, it became a production seedling.
(2) Different species and different plants of the same species have different proportions of callus formation in the morning and evening. At the same time, it is related to explant type, sampling place and season, lighting conditions, culture medium types and other factors. Taxus cuspidata, Taxus mairei and Taxus yunnanensis can all form callus on the induction medium. However, due to the different species and plants of Taxus chinensis, the formation situation is also different.
The results showed that the hydrolyzed complex protein could promote the growth of callus of Taxus cuspidata and Taxus mairei to some extent, but the concentration greater than 0.5% was not conducive to the formation and accumulation of paclitaxel.
When the concentration is greater than 1%, it can promote callus healing and form new growth points without affecting the accumulation of paclitaxel.
Comparatively speaking, 2 days and 4 days are also beneficial to the formation of callus and can also improve the induction rate. Callus in 2-day and 4-day culture medium is bright, large and soft, which is easy to induce callus of Taxus chinensis. However, other medium additives, such as cell suspension culture, B5 medium and carbon source sucrose, can also increase the content of paclitaxel. However, glucose in high-yield sucrose will inhibit the synthesis of paclitaxel. At the same time, galactose can significantly promote cell growth.
GIBSON's research shows that whether it is cell suspension culture or inducing callus cell growth and taxol content formation, it is better in the dark than in light.
No matter what species and parts are used for tissue culture, we should choose the cell components with strong proliferation ability in the middle (the surface cells contain a lot of starch granules, the central cells are seedless, and tubular molecules are easy to differentiate). This is conducive to the formation of cell filaments between cells, thus forming a large cell mass, which is conducive to the signal transmission of small substances between cells. Therefore, the cells of Taxus chinensis exist in the form of cell clusters, producing functional cell bodies, promoting the regionalization of cell clusters and cell functional differentiation, which is the premise for Taxus chinensis to produce metabolites.
3. Artificial cutting propagation of Taxus chinensis
With the decrease of Taxus resources and the increase of demand, it is urgent to make rational use of Taxus resources and develop Taxus industry. Under the principle of ensuring medicinal use and prohibiting the use of wood, branches and leaves can be used more effectively. Under the background of the provincial government's yew project, actively advocate national afforestation. At present, while protecting the existing wild yew resources, artificial cutting is still the most effective and practical means to cultivate yew.
Weihe Forestry Bureau has made active exploration in this field for many years and accumulated quite rich practical experience. 1984, the first artificial clone of Taxus chinensis in China was successfully propagated by cutting. And created the world's first artificial yew forest. At present, Weihe River has the largest seedling base of Taxus chinensis in the world, and the number of seedlings of Taxus chinensis accounts for 1/5 of the total number of Taxus chinensis in the world.
The cutting propagation of Taxus chinensis is better in spring and autumn. Generally, low shed shading treatment should be done when cutting. Generally, the survival rate of cutting can reach more than 70%. But conventional cutting is only about 3%-20%. Shading rate is not less than 60%. Cutting media should be carefully rooted. At the beginning, the humidity should be kept at about 75-85% intermittently. Avoid water loss caused by strong wind.
The factors that affect the survival rate of cutting are generally: tree age, temperature, chemical concentration, substrate, season, humidity, variety and other human factors. According to the data, the highest survival rates of several kinds of yew are: Taxus cuspidata 95%, Taxus mairei 95%, Taxus yunnanensis 90% and Taxus China 86%.
In the process of rooting in the first year, the aboveground part of the cuttings grew slowly, but took root quickly and developed lateral roots. After transplanting in the second year, further shading treatment and seedbed management are needed. Ensure the corresponding environmental conditions and accelerate the growth. The growth rate is the fastest in summer and slower in winter and spring. Pay attention to the change of temperature at this time. Long-term drying can lead to growth inhibition or sudden death. However, after the seedlings of Taxus chinensis are strong in the seedbed, the survival rate of afforestation is very high. It rarely dies and grows rapidly.
Cutting is the most effective way to solve the shortage of Taxus resources and accelerate the construction of Taxus medicinal forest. At the same time, judging from the current market situation, after the second year of logging, the annual seedling price will increase exponentially and will not be greatly disturbed. In recent years, some enterprises and individuals with economic strength have begun to invest in this project, and some quick-acting enterprises or individuals have long used the business opportunities of Taxus to join the ranks of millionaires and multimillionaires.