Practical Cuttage Seedling technique of Taxus cuspidata

Taxus mairei, also known as yew, red cypress pine and Zhu tree, is a large tree or shrub of Taxaceae, with reddish brown bark, thin bark, shallow grooves, irregular leaves arranged into two pieces, slightly sickle-shaped, dark green surface, two gray stomatal bands on the back, and one-year-old branches smooth and glabrous, showing dark green. Up to 20m in height, 1m in breast diameter, the crown is ovate or broadly ovate or triangular-shaped, the branches are dense, the seeds are purplish red, the seeds are oval and the aril is fleshy. The flowering period is from May to June, the fruit ripening stage is October, and the life span is 200,300 years. The young trees preferred shade protection, and after 7-8 years, they liked light and had strong cold resistance, and there was no freezing injury at-45 ℃. It grows in cold and humid climate, loose and fertile soil, good drainage, avoid stagnant water and marshes, soil moisture content is 40%-60%, and grows best on slightly acidic slopes. It is found in Changbai Mountain in Jilin Province at an altitude of 500m to 1000m. Taxus mairei is an endangered species protected by international conventions, and it is also a precious ornamental tree species for landscaping. It can be planted alone, opposite or clustered, can be trimmed into various geometric figures, and can also be used as bonsai and evergreen hedge materials. Its root, stem, leaf, skin, fruit and so on can be used as medicine. Ye Ketong is diuretic, treats hypertension, and has the effect of inhibiting diabetes and treating heart disease. Paclitaxel extracted from Taxus is a new, efficient and broad-spectrum anticancer drug, especially for ovarian cancer, breast cancer, lung cancer, leukemia and so on.

The reserves of Taxus in China are limited. Since taxol was officially approved as a drug for the treatment of advanced cancer by the American FAD in 1992, the wild resources of Taxus in China have been seriously damaged by excessive felling, and the growth of Taxus is very slow, and many biological characteristics limit the development of the natural population. According to WHO statistics, the annual number of cancer patients in the world reaches more than 10 million. Even if the global yew natural resources are harvested, it is only enough for short-term needs, and it will cause irreparable losses to the earth's environment and biodiversity.

In order to rescue, develop and utilize this species, we have adopted the technique of clone cutting propagation. After several years of cultivation and research, we have preliminarily mastered the technology of cutting and cultivating seedlings of Taxus cuspidata.

1 preparation of cutting materials

1.1 Cuttage shed

In order to ensure the survival of cuttings, the temperature and humidity of the nursery must be controlled and the method of cultivation in plastic greenhouse must be adopted. The size of the shed depends on the number of cuttings. According to the size of the seed ear, there are generally 650,1300 cuttings per square meter. When calculating the greenhouse area, in addition to the direct cutting area, the auxiliary area such as road (trail), fertilizer yard and workshop should be added. The time of withholding shed should be more than 10 days before cutting, and if cutting in spring, it should be more than 20 days in advance.

1.2 Cuttage substrate

Sand, vermiculite, perlite, peat, humus soil and furnace ash were used as cutting substrates, and peat was the best. The method is as follows: the cuttage bed is 1.5m wide, first spread 1~2cm thick fine sand on the bed, and spread 5~15cm thick crushed peat soil on the fine sand. This kind of matrix has good permeability, good heat preservation and water retention.

1.3 selection of mother trees and preparation of seed ears

1.3.1, the selection of ear-picking mother trees compared with the mother trees of less than 25 years old, the cuttage survival rates of ear cuttings collected in the same part were 45% and 85%, respectively. The survival rates of 20-year-old ear cuttings and less than 8-year-old ear cuttings collected by the same mother tree are 50% and 95% respectively, because the old mother tree accumulates more rooting inhibitors, the cortex is thick, it is not easy to produce new roots, and the old branches are thin and weak, even if they survive.

1.3.2 the mother trees with ear preparation less than 25 years old can collect outer branches, which are close to the middle and lower periphery of the crown, and the cutting rooting rate of 2-and 3-year-old branches is high. The rooting rate of the shady branch of the mother tree is higher than that of the sunny branch, and the rooting rate of the mother tree in the ear nursery is higher than that of the wild mother tree.

Generally, the spikes of mother trees are collected from February to March. If they are not cut immediately after harvest, the method of snow storage is used to store them in a frozen place below 0 ℃ and checked at any time to avoid mildew and rat bites. When using semi-lignified softwood cuttings, it should be picked along with the cuttings.

2 cuttage

The best time for cutting is when the plant has the strongest ability to regenerate physiologically. The experiment of cutting propagation shows that all kinds of conditions of the cutter are suitable, and the cuttings can take root all the year round, and the cuttings can be propagated at any time.

2.1 time

The effect of hardwood cuttage is the best from April to early May. It is suitable for softwood cuttings from the beginning of the month to the first ten days of August.

2.2 method

2.2.1 cutting cuttings should be cut into 7~30cm strips which are robust and disease-free. The cut panicles should be 30-50 bundles, placed in a place with no wind and shade, and often sprayed with water to keep moist.

2.2.2 effect of hormone treatment on cuttage Survival since 2001, we have collected seed ears on the green Taxus cuspidata in the nursery of Jilin City Greening Management Office (1982 yew) and the street road in Jilin City. Asexual reproduction was carried out in the nursery of Jilin Field Industrial Co., Ltd. The experiment for many years shows that Taxus cuspidata is a kind of plant easy to survive by cutting. experiments were carried out with indolebutyric acid, naphthylacetic acid, indoleacetic acid, ABT2 (rooting powder No. 2) and ABT1 (rooting powder No. 1). Treated with indolebutyric acid 100 μ g / g, it began to take root in 45 days and basically came out in 65 days. ABT2 has a certain inhibitory effect on the cutting of Taxus cuspidata. ABT1 rooting powder was soaked in 50 μ g / g medicine solution to 2cm at the base of cuttings for 24 hours. The wound healing area of inverted T-shaped cuttings was 100%, and the rooting rate was 98%. After 45-60 days, around the phloem of the lower incision, some milky cylindrical roots began to grow at the 1~3mm of the lower incision. the root system reached 3~5cm in about 3 months, while the needles yellowed slightly and showed dark red, and the terminal bud began to grow. After 3 months of growth, it can reach about 2cm. The effect of different concentrations of naphthylacetic acid on rooting rate is extremely significant: 50 μ g / g rooting rate is 56%; 100 μ g / g rooting rate is 30%; 150 μ g / g rooting rate is 27.2%. The difference of rooting rate of different treatment time with 50 μ g / g naphthylacetic acid solution was as follows: the soaking time was 24 hours, 30 hours and 40 hours, and the rooting rates were 34%, 57% and 45%, respectively. The results showed that the best soaking time was 30 hours before soaking, and the rooting rate decreased immediately when the soaking time exceeded 30 hours. The experimental results show that cutting Taxus mairei with 5~7cm cuttings is a good method to expand propagation, save resources and effectively utilize area.

2.2.3 the depth of cuttings is about 1x2 of cuttings, that is, 10cm cuttings, and the part inserted into the substrate is 4~5cm. The different specifications of cuttings, row spacing and middle ear can be defined as 2.5~3cm, 3~3.5cm, 3.5~4cm and 4~4cm. The actual operation is 650,1300 cuttings per square meter.

2.2.4 Management of temperature and humidity after cutting the soil temperature at the bed depth 5~10cm should be kept at 22: 28 ℃, the soil water holding capacity should be 60%-70%, and the temperature and humidity should be 18-28 ℃ and 85% in the greenhouse.

2.2.5 sunshade Taxus mairei cuttings must be sunshaded, reduce direct sunlight, take root shading to 60%-70%, and gradually remove the sunshade after survival.

3 problems that should be paid attention to

3.1 Light intensity

Taxus mairei is a negative tree species, which must be shaded when cutting to avoid direct light and reduce transpiration. If the cuttings are not shaded, those who do not take root will all die, and the rooting rate of 70% shading is the highest.

3.2 soil matrix

Divided into coarse and fine sand beds, the rooting rate of fine sand beds is 20% lower than that of coarse sand beds.

3.8 take tree age and branches

The rooting ability of cutting is related to the age of the tree and the age of the branch itself. for the meristem with the growth ability of young mother tree and tender branch, the rooting rate is higher after cutting, while the rooting rate of new tree and new branch is weakened in the process of growth, so the rooting rate is lower.

3.4 hormone treatment

Young trees and young branches of yew have higher rooting ability, and experiments show that yew can take root without treatment. Improper treatment of hormones will kill the tissue cells of yew and blacken the branches.