Introduction to Encyclopedia of seedlings-- Taxus yunnanensis

Chinese name of Taxodiaceae

Coradin name: Taxaceae

Chinese name of genus: Taxus

Species Chinese name: Taxus yunnanensis

Latin name: TaxusyunnanensisChengetL.K.Fu

Other common names: Yew, Shenmu

National Ⅰ key protected Wild plants (approved by the State Council on August 4, 1999)

Taxus yunnanensis is one of the four species of yew in China. it is a tall evergreen tree with luxuriant branches and leaves and strong vitality. the age of a single tree can reach more than a thousand years, and it is known as "Shenmu" by local minorities. A yew tree in Luobu Township, Weixin County, Yunnan Province, with a height of 72 meters and a breast diameter of 202 centimeters, is 800 years old. Generally up to 30 meters high, dioecious, fruit period from October to November, fruit such as beans, with aril, red.

Taxus yunnanensis is a local endemic species with Yunnan as the central distribution area, which is mainly distributed in Baoshan City and Tengchong County in western Yunnan, and Zhongdian, Lijiang and Weixi in northwest Yunnan. Often born in subtropical mountains with an altitude of 2000 to 3500 meters. Habitats grow scattered or blocky in shady and semi-shady slopes of Zhongshan, subalpine gentle slopes, valleys, dark coniferous forests on both sides of streams, Zhongshan coniferous broad-leaved mixed forests and evergreen broad-leaved forests, and often become lower trees.

Taxus yunnanensis is not only a precious tree species at the provincial level in Yunnan, but also a key protected tree species in Yunnan Province. Bark contains paclitaxel, harringtonine and other ingredients. In recent years, scientists have found that the relevant ingredients of Taxus are effective drugs for the treatment of a variety of cancers; Taxus is also a traditional Chinese medicine, its seeds contain starch and sugar, and the aril is edible.

Taxus yunnanensis is the main tree species for the production of paclitaxel in China. Based on the determination data of taxol and semi-synthetic raw materials baccatin (including 10-deacetyl baccatin Ⅲ and baccatin Ⅲ) in Taxus yunnanensis forest samples for many years, and compared with other Taxus species, it shows that Taxus yunnanensis is a tree species with high content of the above three active components. In the natural forest of Taxus yunnanensis, the taxol content in the bark is about 0.02%, and the highest is 0.0304%. The average content of paclitaxel in twigs and leaves is 0.0102%, and the highest is 0.0217%. The total content of baccatin can reach 0.0808% (bark) and 0.0845% (branches and leaves), both of which have excellent industrial utilization value. The content of drug components in artificially planted Taxus yunnanensis trees did not decrease significantly. The high content samples with taxol content of 0.0421% and Vaca content of 0.103% in the roots of artificial trees have reached the high levels of paclitaxel and baccatin in the world famous taxol raw material trees, Taxus mairei (hybrid) and Taxus mairei. The differences of the three active components among the samples are very large, ranging from several times to 17 times. There may be three reasons: (1) genetic differences in trees; (2) affected by ecological environment; and (3) differences in sample preparation, storage and analysis. The research and improvement from these three aspects are expected to increase the content of medicinal active components of Taxus yunnanensis.

Taxus yunnanensis has excellent material and can be used in construction, furniture and utensils, and its extract paclitaxel has anticancer effect. Is a collection of timber, medicine, greening in one of the precious tree species. In particular, its taxol content is much higher than that of other yew tree species. Taxus has strong adaptability to the environment, and is an excellent economic tree species for improving ecological environment and building beautiful mountains and rivers in the new century. at the same time, it also has a very broad development prospect in landscaping and indoor bonsai, and its plates can be exported. Experts predict that this tree will sell well for a long time, the benefit is extremely high, it is suitable for cultivation in places with favorable conditions for planting in various parts of our country, and the prospect of development is very broad.