What kind of tree is the Maire yew? Characteristics and cultivation value

Alias: Maire yew

Scientific name: Taxus mairei (Lemee et Levl) S.Y.Hu

Family: Taxaceae

I. Tree characteristics

The trunk is straight and full, the branches and leaves are dark green, evergreen through the four seasons, an excellent landscaping tree species; the wood is hard and dense, the sapwood pale yellow, highly resistant to decay, a special industrial and precious carving timber; it can be managed as a medicinal raw material forest to extract taxol and various other anti-tumor substances, and is a national first-class precious protected tree species.

The Maire yew grows slowly and often grows mixed with other broadleaf trees, bamboos and conifers; it is shallow-rooted with well-developed lateral roots, relatively drought-tolerant and high-temperature-tolerant, slow-growing, and prefers moist soil rich in organic matter. The canopy density for seedlings and large trees is between 0.5-0.6, under which growth is good; as canopy density increases, growth weakens. The seed ripening period is October-December, the seeds are red and have a hard outer layer, and only after the outer layer is worn away will the seeds take root and sprout.

II. Cultivation techniques

1. Raising seedlings: The Maire yew currently uses sowing and cutting propagation as the main seedling-raising methods.

(1) Sowing to raise seedlings: The seed collection period is October-December; the collected seeds need to have the outer fleshy aril and the waxy layer on the seed shell removed, then be disinfected and sand-stored to break dormancy. Under natural conditions the sand storage time is 15 months; sow when 80% have cracked white, and generally after 3 months the emergence rate can reach more than 50%.

According to research, the main factor affecting the germination of the Maire yew is the presence of an intraspecific inhibitor, which exists mainly in the seed coat and endosperm; in addition, the impermeability of the outer seed coat also has some effect on its germination. It is currently believed that besides ABA this inhibitor may also contain some other components, and BA can to a certain extent inhibit the activity of this substance. Sand storage treatment with "warm temperature (25 degrees C) stratification for 36 weeks and low temperature 5 degrees C stratification for 12 weeks" can inhibit the activity of the substance, allow it to complete after-ripening and break seed dormancy, thereby shortening the sowing period and meeting the requirement of collecting seeds in autumn and sowing in spring.

(2) Cutting to raise seedlings: Maire yew seeds have dormancy caused by embryo after-ripening; even with various treatment methods, seeds collected and sown in the same year will only germinate successively in the spring and summer of the 3rd year. Using branch cuttings, however, can not only increase the source of seedlings but also maintain the good traits of the mother plant. The main factors affecting the rooting rate of Maire yew cuttings: (1) Age of the shoot and component phenotype: for cutting material, current-year branches and 2-year-old branches are better; old stems, sprouting shoots on branches or after truncation are conducive to producing robust arbor-type plants; (2) Cutting habitat and facilities: in production, low sheds for shading and film covering over the nursery bed are commonly used to keep warmth and moisture; the seedbed temperature is generally 20-30 degrees C, humidity 80%-90%, light transmittance 25%-35%, and can be adjusted appropriately in winter and summer; (3) Hormone treatment and time: soak for 2-4 hours with ABT No. 1, No. 2 at 100 ppm and No. 8 at 10 ppm, indolebutyric acid at 500 ppm, or indoleacetic acid at 100 ppm; rooting powder, indolebutyric acid or indoleacetic acid can also be mixed with talcum powder into a paste, and the base of the shoot dipped in the medicine before cutting, but considering all factors, soaking with indoleacetic acid (IAA) at 100 ppm for 1 hour is optimal; (4) Cutting substrate and cutting length: the Maire yew can grow normally on many single substrates or combined substrates such as river sand, sawdust, perlite, yellow subsoil, gravel, and loam; among these, for 8 cm cuttings the mixed substrate of 46% perlite and 54% yellow subsoil is best, while for 5 cm cuttings perlite is best. In production, 10 cm cuttings and a combined substrate of river sand, perlite, or yellow subsoil and sawdust are commonly used. (5) Cutting season: for hardwood cuttings autumn is better; softwood cuttings can in theory be carried out throughout the entire growing season, but in production the hot summer is generally avoided and they are mostly carried out in April-May.

2. Afforestation: The yew has high requirements for site conditions; the afforestation land should be chosen in shady places with deep, fertile, moist soil. There are mainly two afforestation models: (1) Interplanting under the forest canopy: using Chinese fir and Masson pine large-diameter timber bases and moso bamboo forests (canopy density controlled at about 0.5) to interplant 40-60 plants per mu; (2) According to the experience of Mingxi County, field afforestation in contiguous plots at 1000 plants per mu, with the purpose of afforestation being to extract taxol, taking care to shade, keep moisture, and avoid water accumulation.