Alias: Taxus, Taxus genus
: Taxus chinensis
History: It is recognized as a Quaternary glacial relic and a rare and endangered plant in the world. Ancient trees have been on the earth for more than 2.5 million years.
Development value: evergreen needles and red beans bearing cherry fruits are rare and endangered plants left over from glaciers after the fourth century. They are rare natural distribution in the world and are national key protected plants. Among them, excellent wood, red, tough and durable, is a precious timber tree species. Especially because it contains paclitaxel and precious anticancer effect, this magical drug is the best anticancer drug in the world at present, second only to adriamycin and cisplatin, the best-selling and most popular anticancer drug in the international market so far, and the last line of defense for patients with advanced cancer, which has high development value.
It is suitable for planting Taxus chinensis in the north and south, and has the characteristics of shade-loving, drought-resistant and cold-resistant, and the requirement for soil PH value is 5.57.0. It can be simply interplanted with other trees or orchards, among which Taxus japonicus, as the heritage of Quaternary ancient glacial trees, is full of vitality under harsh climatic conditions, making life on earth more than 250 years. It not only has developed lateral roots, lush foliage and strong germination ability, but also can adapt to a wide range of climate and requirements for soil width, and is resistant to pruning, cold and pests. And can grow into towering trees, and some plants can even grow for thousands of years, which can be used as medicinal varieties and green varieties. In folklore, Japanese yew is called "the geomantic tree of God".
The State Forestry Administration has given clear instructions to the ongoing "Taxus chinensis Project": "Taxus chinensis as a protected species, including those with good ecological benefits, will be strongly supported by the state within a proper range. To establish a yew forest, all sectors of society should participate in afforestation in the form of contracting, leasing, auction and joint-stock cooperation to promote and encourage the development of the cause. " At present, the development goal of Taxus chinensis industry in Weihe forest region is: the resource reserves are in the forefront of the world, and the seedling output is in the forefront of the world. Therefore, the "yew project" is not only an urgent life-saving project, but also a great benefit to the cause of human sunshine.
Compared with the world, Taxus resources account for more than half, but the demand for taxol worldview is far from enough. Since 1992, the US Food and Drug Administration (FAD) has approved paclitaxel for drug treatment of advanced cancer, and the resources of cutting down wild yew have been increasing, which has been seriously damaged. Many biological characteristics of wild yew restrict the development of natural communities. According to statistics, in many cancers in the world, the incidence of extracting paclitaxel for thousands of years or more is 0.006% and 0.06%, and it consumes 700 ~ 1000 tons of yew bark. Even if the whole world harvests yew bark net, it can only maintain short-term demand. And the chemical synthesis of paclitaxel is still in the laboratory stage. Therefore, the establishment of artificial Taxus resources will promote the promotion of medicinal material Taxus timber base.
Several propagation methods of Taxus seedlings at present
1. First, sterile culture.
Protecting the resources of Taxus chinensis and rapidly propagating seedlings are fundamental to solve the wood structure of Taxus chinensis, and large-scale construction of artificial Taxus chinensis forest is the key. When the seedlings of Taxus chinensis are propagated in hotels and hotels, the purpose of seed storage is to live until the sand seeds are mixed or treated at high temperature, which is the habit of dormancy and germination during the winter break and has received good results. To sow the seed coat, soak the seed in warm water and wipe the wound before hormone treatment. Shading after emergence is the key. To prevent 40% of seedlings from getting wet at high temperature, it is advisable to transmit light. The germination rate of Taxus japonicus can reach 70% to 80%, and it needs a temperature above 65438 05 degrees.
The growth dynamics of seedlings are as follows: the growth of seedling height and stem diameter is slow in the first two years, the average seedling height of about 10CM increases every year, and the growth rate accelerates after transplanting for one year. Increase to 2030CM in 3-5 years.
2.
Tissue culture and propagation of Taxus chinensis are based on the totipotency and clonality of plant tissue culture cells. The stem, needles, bark, cambium, aril and embryo of Taxus plants are used as explants for culture.
( 1)。 Select excellent varieties and organs of Taxus chinensis, such as Taxus cuspidata (taxol content), as explants for callus formation. After rooting medium culture, Taxus seedlings with suddenly improved quality were formed. Mairei and many tissue culture laboratories. After the matrix exercise, the seedlings were transplanted and it was checked that the production of seedlings was popular.
(2)。 The callus formation rate of late and early yew is also different among different types and different plants of the same species. At the same time, it is related to explant type, sampling site and season, lighting conditions, culture medium types and other factors. In the induction medium, Taxus japonicus, Taxus China and Taxus mairei. Mairei can form callus. But there are also differences, due to the formation of different types and yew plants.
The results showed that a certain degree of envelope protein hydrolysis promoted the growth of callus of Taxus japonicus and Taxus yunnanensis, but when the concentration was greater than 0.5%, it was not conducive to the formation and accumulation of paclitaxel.
When the concentration is greater than 1%, it can promote the healing of tissue injury and the formation of new growth without affecting the accumulation of paclitaxel.
Comparatively speaking, 2 and 4 days are also beneficial to the formation of tissue injury and can also improve the induction rate. The callus of Taxus chinensis is bright in color, wide and soft in 2 or 4 days, and it is easy to induce callus. However, other medium additives, such as cell suspension culture and carbon source of B5 medium, can also increase the sucrose content of paclitaxel. However, farmers with high sucrose and glucose will inhibit the synthesis of paclitaxel. At the same time, galactose significantly promoted cell growth.
Gibson's research shows that the cell growth and taxol content formation of these two kinds of cell suspension cultures or calli are better in dark than in light.
No matter what kind of tissue culture and location, there is strong cell production and diffusion (the surface cells contain a lot of starch granules, and the central cells are seedless and easy to differentiate into tubular molecules). This is composed of substances that are conducive to the formation of intercellular Streptomyces cells, thus forming a large cell block, which is conducive to the transmission of small signals between cells. So as to produce functional cells in the form of cells in vivo and promote the regionalization, differentiation and functionalization of cell clusters, which is the premise of producing the metabolite Taxus chinensis.
3. Cutting
The artificial propagation of Taxus chinensis cuttings is better in spring and the hard branches are better in autumn. Cutting is generally used when shading in low shed. Generally, the survival rate of cutting can reach 70%. In the past, cuttings were only 3% to 20%. Shading rate is not less than 60%. Cutting and rooting bases should be treated with caution. When the humidity is maintained at about 75-85% at the beginning of batch processing. Avoid strong winds caused by dehydration.
The general factors affecting the survival rate of cutting are: age, temperature, drug concentration, substrate, season, humidity, variety, human factors and so on. According to the data, the survival rate of several kinds of yew can generally reach 95% of Japanese yew, 95% of southern yew, 90% of yew and 86% of China yew.
In the process of rooting in the first year, the cuttings grow slowly on the ground, but take root quickly and develop lateral roots. After transplanting, shading and seedbed management in the second year. Ensure proper environmental conditions and accelerate growth. It grows fastest in summer and slowly in winter and spring. You should pay attention to the change of temperature. Drying can lead to long-term growth inhibition or death. However, the survival rate of Taxus chinensis planted in Fuzhuang seedbed is very high. It rarely dies and grows rapidly.
Taxus cutting is the most effective way to solve the shortage of resources and accelerate the construction of Taxus medicinal forest.