basic document
Chinese name: Taxus chinensis
Scientific name: Taxaceae
Alias: yew, cypress
Genus: Taxus chinensis
History: The ancient tree species left over from Quaternary glaciers have a history of 2.5 million years on earth.
Development value: Evergreen needles and exotic red bean fruits with big cherries are rare and endangered plants left over from the 4th century glaciers. Rare in the world, it is listed as a national key protected plant. Their wood is very good, red and bright, tough and durable, and it is a precious timber tree species. Especially because it contains paclitaxel, a specific anticancer drug, it is very precious. This magical drug is the best anticancer drug in the world after adriamycin and cisplatin. It is the best-selling and hottest new anticancer drug in the international market so far, and it is also the last line of defense for patients with advanced cancer, which has high development and utilization value.
Ecological habit
Taxus chinensis is suitable for planting in north and south, and has the characteristics of shade-loving, drought-tolerant and cold-resistant. The soil PH value is required to be 5.5 ~ 7.0, which can be interplanted with other tree species or orchards, and the management is simple.
Among them, Taxus cuspidata, an ancient tree species left over from Quaternary glaciers, has survived on the earth for more than 2.5 million years with its tenacious vitality under harsh climatic conditions. It not only has developed lateral roots, lush foliage and strong germination, but also adapts to a wide range of climate, requires wide soil quality, and is resistant to pruning, cold and insect pests. But also 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, Taxus cuspidata is known as the "sacred tree of geomantic omen".
morphological character
Taxus is an evergreen tree with DBH 1 m and a height of 20m. It has very special requirements for the small environment where it grows. It can only be seen in the deep mountains and forests at an altitude of 2500-3000 meters, and it takes 50-250 years to become a timber.
The origin of the name
Taxus chinensis is a star in the plant world in recent years. Because paclitaxel can be extracted, it is an internationally recognized anticancer agent and a national first-class protected tree species. The red beans of Taxus chinensis are the same as the acacia beans in the south, and they are red outside and bright inside, which can support people's acacia. Taxus chinensis is also named after the same fruit as red beans, so it is named Taxus chinensis.
classify
Taxus classification
Distribution and species of Taxus in China;
Except Austrotaxus Spicata from Australia, which is produced in the southern hemisphere, all other yews are produced in the northern hemisphere. There are 4 species of Taxus in China. China 1 is distributed in most parts of China. Taxus cuspidata is mainly distributed in Changbai Mountain in Jilin Province and Heilongjiang Province, with a small amount in the eastern mountainous area of Liaoning Province. Taxus yunnanensis is mainly distributed in western Yunnan and Dizhou 16 county, with a total area of about 90,000 square kilometers. It is characterized by wide distribution, scattered growth and no pure forest, and most of the forests are scattered trees. Taxus chinensis var. mairei is mainly distributed in pure forests in eastern Yunnan, southwestern Yunnan and eastern Yunnan, and most of them are scattered trees in the forests. Taxus tibetica is mainly distributed in northwest Yunnan, south and southeast Tibet.
Efficacy of Taxus chinensis: diuresis, detumescence, treatment of nephropathy, diabetes, nephritis edema, dysuria, gonorrhea, etc. Warming kidney and dredging channels, treating irregular menstruation, postpartum blood stasis, dysmenorrhea and other effective effects.
Taxus species ii
Taxus around the world can be divided into 1 1 species according to their growing areas and biological characteristics. Australia's AUSTROTAXUS SPICATA is produced in the southern hemisphere and distributed in the temperate and subtropical regions of the northern hemisphere. There are 4 species 1 varieties in China.
1, Taxus cuspidata STEB. ET IUCC is mainly distributed in Changbai Mountain in Jilin Province and Heilongjiang Province, and a small amount is distributed in the eastern mountainous area of Liaoning Province.
Taxus cuspidata
Latin name: Taxus cuspidata
Plant name: Taxus cuspidata
Scientific name: Taxus cuspidata
Other names: yew, cypress, cypress, yew, rice tree, etc.
Family name: Taxodiaceae
Latin name: Taxaceae
Genus name: Taxus chinensis
Taxus cuspidata is one of the four varieties of 1 in China. The other three varieties of 1 are Taxus yunnanensis, Taxus tibetica, Taxus China and Taxus mairei.
[Distribution area]
Mainly distributed in northeast China, Japan, North Korea, Russia (Amur, Sakhalin, etc. ) and northeast Asia. Such as eastern Liaoning and Jilin.
Temperate coniferous and broad-leaved mixed forest areas (major cities: Harbin, Mudanjiang, Hegang, Jixi, Shuangyashan, Yichun, Jiamusi, Changchun, Siping, Yanji, Fushun, Tieling and Benxi)
[biological characteristics]
Habitat is shade-tolerant, and it can also grow under dense forests, and it is not a forest all the year round. It is more common in coniferous and broad-leaved mixed forests dominated by Korean pine. Born on rocky or barren soil on the mountain, it is mostly shrub-like. The annual average temperature in the country of origin is 2 to 7 degrees Celsius, and the annual average precipitation is 750 ~1000 mm.. Most of them are scattered under wet and fertile coniferous and broadleaved mixed forests on shady or semi-shady slopes. Sexual preference for cool and humid climate, resistance to low temperature below minus 30 degrees Celsius, strong cold resistance, optimum temperature of 20 degrees Celsius to 25 degrees Celsius, avoiding sudden heat, sudden cooling and air drying, belonging to negative tree species. Like wet but afraid of waterlogging, it is suitable for planting on loose, wet and well-drained sandy loam.
[growth area]
Taxus cuspidata is a tree species in Northeast China, which is adapted to grow in Northeast China, Beijing, Tianjin, Hebei, Shanxi, Shandong, Zhejiang, Jiangsu, Shanghai and other areas north of the Yangtze River.
[Annual growth rate]
The plant height of Taxus cuspidata grew slowly in the first three years, and the annual growth was about 10- 15 cm. After transplanting for one year, the growth is accelerated, and the annual growth of seedlings over three years can reach 20-30cm.
[Appearance characteristics]
The characteristic of Taxus cuspidata is that the twigs of trees turn yellow-green or reddish brown in autumn. Its leaves are in two rows, slightly curved and sickle-shaped, which looks like a ball at close range and a flower at a distance, which is extremely beautiful.
[growing habit]
Negative, like cold and humid climate, shallow root system, afraid of waterlogging, avoid salt and alkali.
[medicinal value]
Use stems, branches, leaves and roots as medicine. The main components contain paclitaxel, taxane and diterpenoids. Has anticancer effect, and has effects in inhibiting diabetes and treating heart disease. According to the identification of authoritative departments and related reports, Taxus chinensis in China has a certain content when extracting taxol, especially Taxus cuspidata growing in special environment, and the highest content can reach three ten thousandths (according to A.G.F.Neto). Unique climatic conditions are conducive to the deposition of substances in plants. If Taxus cuspidata is moved to the south properly, the growth period can be increased, the growth environment can be improved, the synthesis of effective components in the body can be facilitated, and the content and quality can be improved.
[green browsing]
Taxus cuspidata is not only a rare medicinal plant, but also a good product for gardens, courtyard greening and beautification. It is the most precious and rare advanced greening tree species at present. The unique ornamental value of bonsai is another major feature of Taxus cuspidata. The bonsai of Taxus cuspidata treated by dwarfing technology is simple and elegant in shape, with compact but not dense branches and leaves, stretching but not loose. Red stems, red branches, green leaves and red beans make them have multiple ornamental values of ornamental stems, branches, leaves and fruits. Smooth red stems represent magnanimity and nobility, evergreen needles express perseverance and eternity, and red beans shaped like "acacia beans" show love and yearning. The whole plant is exquisitely sculpted, extraordinary and free from vulgarity, and has a strong flavor of life and cultural heritage. Taxus cuspidata resources are scarce, and it is listed as a national first-class rare protected tree species.
2. Taxus yunnanensis is mainly distributed in 16 counties in western Yunnan and Dizhou, with a total area of about 90,000 square axioms. It is characterized by wide distribution, scattered growth, no pure forest and scattered trees in the forest.
3. Tamarix 3.IUCC is mainly distributed in northwest Yunnan, southern Tibet and southwest China.
4. Taxus China (. Penaeus China
5. Taxus mairei is mainly distributed in pure forests in eastern Yunnan, southwestern Yunnan and eastern Yunnan, and most of the rest are scattered trees.
6. Taxus media is a hybrid introduced to China at the end of 20th century. Its female parent is Taxus cuspidata and its male parent is Taxus barkeri. It has only 80 years of history in the United States and Canada. Taxus media is mostly shrub type, because it can only grow into shrubs, but not trees, so it is a good variety for greening.
On a global scale, although yew is distributed in the United States, Canada, France, India, Myanmar and China, yew in Asia has the largest reserves. Among them, China's yew reserves account for more than half of the global reserves, and among the 1 1 varieties, there are five in China.
Medicinal value
Taxol, a new source of anticancer drug, is an effective and commonly used anticancer drug, but it can only be collected from the needle-like leaves of an endangered plant at present, and the demand for this drug is likely to exceed the production capacity of this tree. Recently, researchers announced at a meeting of the American Chemical Society that they had isolated this compound from hazel trees and fungi. This discovery may provide enough new sources for the drug, and may also greatly reduce its cost. Paclitaxel, also known as paclitaxel, is one of the most popular cancer drugs in the world. It is used to treat uterine cancer and breast cancer, and many breast cancer patients still take it to prevent the recurrence of cancer. Although the supply of this drug is still sufficient, the demand may increase soon: researchers are testing the efficacy of this drug for Alzheimer's disease, multiple sclerosis and other cancers. If the drug is really effective for the above diseases, then the drug will become in short supply. Because the drug is extracted from the needles of Taxus Pacific and then processed. Taxus Pacific is an endangered plant, which grows on the Pacific northwest coast of North America. Angela Hoffman, a chemist at Portland University in Oregon, USA, has been looking for ways to increase the yield of taxol in Taxus chinensis. Unexpectedly, she found a new source of the compound in another completely unrelated research topic. She and her colleagues were studying hazel trees, trying to find out why some hazel trees were more susceptible to Fusarium wilt. The disease destroyed hazel trees in Willamette Valley, Oregon. The researchers extracted extracts from several hazel trees and purified and analyzed these samples. Hoffman found the chemical characteristics of paclitaxel in it. Hoffman and her colleagues found that the leaves, branches and fruits of hazelnut contain paclitaxel, although the content is only 10% of that of Taxus chinensis. They also found that fungi growing on hazel trees can also produce paclitaxel. David Hawke said that in the end, the discovery of fungi may be the most valuable. David Hawke is a natural product expert in a pharmaceutical company in Worcester County, Massachusetts, USA. He said that yew also contains taxol-producing fungi. Hawke stressed that if the drug can be produced in vats with fungi, "it will definitely be valuable."
The medicinal value of Taxus chinensis mainly lies in its extract-secondary metabolic derivative-paclitaxel. According to the research results of Dr. Fang (Fang-1997 graduated from Peking Union Medical College and studied under Professor Liang), paclitaxel was originally isolated from the bark of Taxus brevifolia as an anti-tumor active ingredient. It is one of the best drugs for the treatment of metastatic ovarian cancer and breast cancer, and also has obvious curative effect on lung cancer and esophageal cancer, and has obvious inhibitory effect on nephritis and parvovirus inflammation. The anti-cancer mechanism of paclitaxel is that paclitaxel can bind to trace proteins, promote their polymerization, inhibit the mitosis of cancer cells and effectively prevent the proliferation of cancer cells.
In order to reduce the damage to wild Taxus resources, people began to extract the precursor compound 10- deacetylbaccatin ⅲ from the branches and leaves of Taxus chinensis, and then semi-synthesized it to prepare medicinal taxol. Paclitaxel is a broad-spectrum and powerful anticancer drug recognized in the world at present, which has a unique anticancer mechanism.
The earliest report abroad was 197 1 extracting paclitaxel from Taxus chinensis in the United States, and 1992 was approved for clinical use by the US Food and Drug Administration (FDA). It has been proved to be effective for a variety of cancers, especially ovarian cancer and breast cancer, with a cure rate of 33% and an effective rate of 75%.
On the other hand, on a global scale, countries around the world gradually accept the treatment methods and principles of traditional medicine (traditional medicine refers to the medical methods to protect and restore health before the emergence of modern medicine). China has a long history in traditional medicine, such as anesthesia, acupuncture and Chinese herbal medicine.
Appraised by authoritative departments and related reports, China yew has a certain content in refined taxol. The content of Taxus cuspidata and Taxus mairei is higher, and the content of Taxus cuspidata with special growth environment is the highest (the content can reach two ten thousandths). The unique climatic conditions are favorable for the deposition of plant dry matter. If Taxus cuspidata is moved to the south properly, the growth period can be increased, the growth environment can be improved, the synthesis of effective components in plants can be facilitated, and the content and quality can be improved.
At present, there are three ways to obtain paclitaxel: 1. Natural extraction, 2. Synthetic, 3. Semi-synthetic and 4. Biological fermentation. The latter three methods mostly stay in the laboratory stage.
(1) Taxol biosynthesis;
The molecular formula of paclitaxel is C47H5 1NO 14, which is a natural secondary metabolite with terpenoid cyclic structure. It is mainly composed of taxane ring and side chain. It is of great significance to study its biosynthesis to improve the synthesis efficiency, clone combination, form key enzyme genes and increase the yield of paclitaxel. At present, the key is whether we can find one or two key enzymes and purify and clone their genes. It remains to be seen whether the cloning of Taxus gene can be broken through, but the imaginative way people have found is still in the laboratory stage.
(2) Chemical synthesis of paclitaxel
According to research and reports, the activity of 10- deacetylbaccatin ⅲ isolated from Taxus plants is obviously lower than that of paclitaxel, but it can be extracted from Taxus needles. This substance can synthesize paclitaxel through four chemical processes. Great progress has been made in solving the new source of paclitaxel. The American research team led by Dr. NICOLAOU reported the results of total synthesis of paclitaxel by chemical methods in 1994. However, chemical synthesis has not completely broken through in essence and has no application value at present.
(2) Microbial synthesis of paclitaxel
STTERLE et al. isolated a parasitic fungus (Taxomyces andarea) from the phloem of Taxus brevifolia, which can produce taxol and related hydrocarbons in a specific culture medium, but the current yield is extremely low and cannot be used for production. Recombinant DNA technology is expected to improve the yield of paclitaxel.
Besides bark, root is the organ with the highest taxol content. People use Agrobacterium rhizogenes to soak the explants of Taxus plants to induce rooting. This method does not need exogenous hormones, the hair roots grow rapidly and the genetic traits are stable, so it is paid attention to. If we can find a way to synthesize paclitaxel or its similar derivatives, combine the key enzymes obtained by microbial synthesis with the cloning of Taxus related genes, we can make a breakthrough in this method.
With the introduction of the 5th Beijing Biomedical Development Forum, the general development process of extracting paclitaxel from plants is as follows:
Since the 1960s, the discovery of new anticancer drugs mainly comes from the metabolites of primitive plants, that is, several anticancer chemotherapy reagents currently used, which are not compounds extracted from higher plants.
Such as "Catharanthus roseus alkaloids" isolated from Catharanthus roseus.
"Epipodophyllotoxin" derivatives isolated from podophyllum.
Camptothecin derivatives isolated from Camptotheca acuminata
So far, the component of "Taxus chinensis Bunge" separated from Taxus chinensis Bunge has been obtained.
Related technologies and equipment for extracting paclitaxel;
1. Key technologies and related data of extracting taxol from Taxus chinensis.
2. Precise determination methods, quality standards and related data of paclitaxel content.
3. Impurity removal and ultra-clean equipment.
4. HPLC and HPLC analytical columns, etc.
Several antitumor drugs made from paclitaxel;
1. daksu
Heilongjiang Taxus Technology Co., Ltd. produces broad-spectrum anticancer drugs for treating parvovirus inflammation such as breast cancer and ovarian cancer.
2. Taxus chinensis capsules
Produced by Chongqing Sino Company, it is a pure Chinese medicine for the treatment of advanced cancer, which is developed by adsorption extraction and dispersion preparation.
3. plante
A broad-spectrum anticancer drug for promoting tubulin polymerization and making it difficult to depolymerize. Thereby inhibiting the division of cancer cells. Has obvious curative effect on cervical cancer, breast cancer, small cell lung cancer and melanoma.
4. Squibb Company of the United States: paclitaxel intravenous injection or infusion.
5. A new compound paclitaxel preparation produced by European Squibb and Roche multinational company is used to treat refractory advanced breast cancer and semi-systemic (cancer cell) disseminated diseases, which brings good news to many advanced breast cancers.
Landscape greening value
[Edit this paragraph]
2000 seedlings can be planted per mu. After three years, the annual output of branches and leaves 1 ton or more. It is also suitable for planting in front of and behind houses, on wasteland and on both sides of roads. Once planted, it benefits for many years and has remarkable benefits. The tree shape of Taxus chinensis is beautiful, and the color matching of red and green when the fruit is ripe is intoxicating. It can be widely used in soil and water conservation, forestry and horticultural ornamental forests, and is an excellent tree species to improve the ecological environment and build beautiful mountains and rivers in the new century.
It also has a very broad development prospect in landscaping and indoor bonsai. For example, the high-grade bonsai made of rare yew trees sold for 300,000 yuan/pot in Beijing, Shanghai, Shenzhen and other places, becoming the upstart in urban greening and home beautification, and being vividly called the precious "cash cow".
Useful disaster
Taxus chinensis is an ancient tree species, which has lived in western Yunnan since the Ice Age. Its wood is hard and grows slowly. It takes 100~250 years from seed landing to tree growth. For several years, no one has ever disturbed their quiet life, because this kind of tree is useless to the local people and can only be used as a chopping block at most.
197 1 year, two American chemists successfully isolated a substance from the trunk of Taxus chinensis, named it paclitaxel, and announced its chemical structure. From 65438 to 0982, paclitaxel was proved to have special effects on ovarian cancer, testicular embryonic cancer, breast cancer and other cancers in clinical experiments, and its side effects were far less than other anticancer substances found at that time. The research results caused a sensation after being published, and it was hailed as the most important discovery in this field for decades.
Taxol in nature mainly exists in the whole body of Taxus chinensis trees, and the content of bark is the highest, reaching about one in ten thousand. However, Taxus chinensis is a slow-growing tree species, which is very rare in the world and has long been listed as a protected tree species in the United States. In Asia, China, Myanmar, Indonesia and other countries have more wild yew.
1992, paclitaxel was officially certified by the US Food and Drug Administration and allowed to go on the market.
1992 in the summer, the first wave of yew bark war started in northwest Yunnan, and a large number of businessmen poured into the forest area to buy yew bark, which was unprecedented. A few months later, the acquisition suddenly stopped and the local forestry department recorded the wave of acquisition. According to insiders, after the news that the United States approved the listing of paclitaxel spread to China, some speculators thought it was profitable to buy it in northwest Yunnan where yew was concentrated. Because this kind of bark is not convenient to sell to the United States, this trend naturally stopped. However, for China, this is the beginning of paclitaxel fever.
In the United States, since 1992, paclitaxel has been regarded as one of the three first-choice anticancer drugs in clinical application, and its value has increased year by year. Patent-holding American manufacturers are pushing the price of paclitaxel higher and higher, reaching three or four million dollars per kilogram, while the supply does not exceed 100 kg. In this case, many American hospitals tend to buy paclitaxel abroad, and paclitaxel has become the drug with the most investment potential, thus setting off a paclitaxel investment fever all over the world.
So far, the United States is still the largest consumer of paclitaxel. Taxol produced in China is powder, almost all of which are exported to the United States. In particular, there are a large number of wild yew in the United States, but American laws allow the import of paclitaxel from abroad, but never allow the use of yew in China.
Since 1992, due to the backward understanding and legislation of the value of Taxus chinensis in developing countries, except for a few countries such as the United States and Canada, reports about the artificial destruction of wild Taxus chinensis have appeared on various environmental protection websites and media all over the world.
PACLI TAXEL 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 curative effect and little side effects on many cancers in the past 15 years after adriamycin and cisplatin. 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.
Taxol is mainly extracted from the roots, skins, stems and leaves of Taxus chinensis. Because of the complex extraction process, it is difficult to remove chlorophyll from the stock solution, and because of the large equipment investment and lack of raw materials, the conventional extraction of paclitaxel developed late in China and just started in the 1990 s.
At present, about 6.3 million patients worldwide die of cancer every year. There are about 4 million people in the United States, Europe and Japan alone every year. Treating these patients consumes about 1500~2500 kg of paclitaxel every year. The world can only produce about 350~500 kilograms of paclitaxel every year. Among them, the United States can produce 25~50 kilograms, while China can only produce about 50 kilograms. Therefore, the market development and application potential of paclitaxel is huge. At the same time, the large-scale planting of Taxus raw material timber forest base also contains huge market opportunities. So the value of yew has doubled.
In foreign countries, the Canadian Botanical Medicine Company, the American Titan Chemical Company and the American Squibb (BNS) Company were the first companies to develop taxol by using yew, with the strongest technical strength and economic strength. Squibb has dominated the world paclitaxel market for 20 years. A considerable part of the raw materials used by the company to refine paclitaxel are imported from China or obtained through other channels, and then its product paclitaxel injection is sold in China for huge profits.
The content of paclitaxel produced in China is above 98%, and the export price is generally in 800 yuan/gram RMB. In foreign countries, each gram of paclitaxel is made into 33 grams of injection, each containing about 30 ml of paclitaxel, which is about 2500 yuan in China. In other words, each gram of imported paclitaxel used by cancer patients in China is equivalent to paying 80,000 yuan, which is more than 600 times the price of gold.
Because of this, the wild yew in China suffered unprecedented logging and destruction in just over ten years, and the wild stock decreased sharply. Some areas are even on the verge of extinction. Therefore, protecting the existing resources and artificially expanding the total amount of Taxus resources are placed in front of people of insight.
cultivation techniques
The State Forestry Administration has a clear instruction on the current "Taxus chinensis Project": "Taxus chinensis is a first-class protected tree species in China, with good ecological benefits and extremely high economic value. The state supports the vigorous construction of yew forests in appropriate areas and encourages all sectors of society to participate in afforestation and greening in various forms such as contracting, leasing, auction and joint-stock cooperation. " At present, the development goal of the yew industry in Weihe Forestry Bureau is: the resource reserve is the first in the world, and the seedling output is the first in the world. Therefore, the "yew project" is not only an urgent life-saving project, but also a great sunshine cause that benefits mankind.
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 key to solve the problem of taxol raw materials is to build a large-scale Taxus plantation.
When raising seedlings of Taxus chinensis seeds, it is necessary to maintain the storage mode of seeds, and store sand seeds together 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 mairei 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. The annual growth can reach 20~30CM in 3~5 years.
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 culture plants.
(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.
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