The Preliminary Study In Introduction And Breeding Of Pinus Flexilis James

The central and western regions of Inner Mongolia exist many problems, such as the climatic drought, scarce vegetation, lack of appropriate tree species, the urban landscape species is also very scarce at the same time, relatively speaking, urban forest because of the needs of landscape position and the species richness, it has great significance to introduce alien fitness trees to enrich urban tree resources of the arid and semi-arid areas. Pinus flexilis James. are also widely distributed in North America, which are the pine trees have strong adaptability and nice view, moreover they are evergreen tree species, the climatic conditions and ecological environment of their natural distribution area are similar to the central and western regions of Inner Mongolia, so it is feasible to introduce Pinus flexilis James. into cities and towns in Inner Mongolia. Through the mensuration and comparison on the growth indicators, preservation rate, the resistance of Pinus flexilis James. for different geographical provenance in different pilot areas (Bainijing Forest Farm and pilot terra in Hohhot), we draw the following preliminary conclusions:1 By the comprehensive analysis of annual growth rule on the height, diameter, root and biomass of Pinus flexilis James., found that Pinus flexilis James. seedlings have two fast-growing period every year are July and September, so at the breeding time, it is necessary to take full advantage of the fast-growing period of Pinus flexilis James., in order to improve the quality of breeding. In the month of June and July the mortality rate of Pinus flexilis James. is relatively high, so do well the seedlings management for this period (anti-damping-off, anti-high temperature) can greatly enhance the preservation rate of seedlings.2 Through the comprehensive analysis about the numerical value of the nursery germination rate, the survival rate and preservation rate, height, diameter, root and biomass for seven different geographical provenance in different pilot terra (Bainijing Forest Farm and pilot terra in Hohhot), concluded: in the central and western regions of Inner Mongolia, the best adaptability of Pinus flexilis James. for introducing is from Stockton California, furthermore Bainijing is more fit for introduction than in Hohhot.3 Pinus flexilis James. seedlings have a certain ability of cold resistance and drought-resistant, which are able to adapt to the cold and arid climate in central and western regions of Inner Mongolia. In the course of breeding, the different irrigational ways can affect chlorophyll and proline content of Pinus flexilis James. seedlings in order to influence the resistance of Pinus flexilis James. seedlings, so the correct way of watering is very important to cultivate high-quality Pinus flexilis James. seedlings. We can educe the results by analyzing the test on drought resistance and cold hardiness of Pinus flexilis James. seedlings: the best way of irrigation is watering 100 ml every two days (to maintain soil moisture around 13.20 percent), the best cold resistance measures is to spread a flat of grass shade, and then cover the soil about 5 cm thickness or directly casing (the thickness should just cover the seedling).