The Introduction And Breed Techniques Of Chilopsis Linearis

Chilopsis linearis, to 10m in height and 9m in crown width, deciduous shrub with dense leaves and tresses,white and pink flower with pleasant fragrance, distributes widely in desert areas of south-western America and northern Mexico. The tree has the strong resistibility to flowing sand and seasonal flood. So it can be used to control flowing sand and beautify surroundings. In 2000 when the project start, this shrub was introduced into Turpan, Dunhuang,Minqin and Tiqnshui for the adaptability to local climates and ecological features by means of comparing and trial in wild. The followings are some results:The main propagation methods of Chilopsis linearis are seedling cultivation in field, seedling cultivation in container and seedling cultivation with cutting. For seedling cultivation in field, the way of covering seedling bed,ideal time and depth of sowing seed are the key factors influencing on the rate of sprouting. In drought sandy land, Lithosphere blanket can keep water, increase warmth and prevent from land caked so that the quality of seedling can be improved because of the shade of seedling. The ideal time for sowing seed is from the last ten-day period of April to the first ten days of May in this area. The ideal depth for sowing seed is 1.0cm-1.5cm. For seedling cultivation in container, it is proper to use medium sand mixed with organic fertilizers, and nursery container in paper cell that is only closed-down, 15cm in depth and 8cm in diameter. The key factors influencing on cutting seedling-raising is the time, a part of branches and potting mixture. It is better to use Aeolian sandy soil as potting mixture with moderate peat. Half ligneous wood cutting, more than 0.6cm in branch diameter, are good for cutting. The best time for cutting is October in greenhouses or July in the field. Generally, it had better use cutting as soon as possible. For seed storage of seedlings, the appropriate temperature for conserving seedlings of Chilopsis linearis must be above -5℃and sand water content must be below 2.5%. The dry sand (sand water content is 1.5%-2.5%) that is used as burying materials,1m in storage depth in the field, is a good choice in cold region of north China. Comparing to seedling cultivation in field, container seedling is more expensive and less quality. Therefore the seedling cultivation is suggested for the production of seedlings of Chilopsis linearis. The method of cutting seedling cultivation is worth to wide use because cutting seedling grows quickly in cutting year and is woody for seedling surviving in winter.The seed of Chilopsis linearis is out-cotyledon. After 3-5days sowing, the true leaves of the seeding come forth for the photosynthesis. The young seedlings start growing fleetly in June. Growth and development stops in September. Seedlings height and taproot growth are more dominant than the other parts of the body.Chilopsis linearis have best adaptability in Turpan, where the growth of 1-year and 2-year seedlings is much more than one in Dunhuang,Mingin and Tianshui. Potted 2-year-old seedlings can reach 3.3 meters in height, blossom and bear fruits normally. In Dunhuang and Mingin, they are frozen so severely that young seedlings hardly can survive winter. And it just flowers but can't bear fruits normally. In Tianshui, they can survive winter, but can not blossom and bear fruits normally.Chilopsis linearis has strong heat-resistance. Its mean heat-resistance index is 1.81 and general heat resistance index is 2. The temperature that causes half of dying seedlings is 64.79℃. It's cold-resistance is poor. Mean cold- resistance index for single tree is 4.23. Mean cold-resistance index is degree 4. It has good adaptability for light. It can grow under different intensity of light. The growth of branches is obvious increase with the increase of light intensity.