Dogwood Asexual Reproduction Technology

Macrocarpium officinalis, one of the famous and valuable traditional Chinese medicines, has rather high medical and nutritious values. At present, Macrocarpium officinalis is mainly reproduced through seeds, which causes mixed up seed quality, late fruit's ripening, low output of fruit and efficiency and severely affects the quality and quantity of herbal medicine Macrocarpium officinalis, its exploitation and development is thus restrainted. So to plant excellent Macrocarpium officinalis clones produced through asexual propagation is a must in order to realize early ripening, early harvest, good quality of Macrocarpium officinalis and high efficiency of Macrocarpium officinalis production. . What is mainly discussed in the article is asexual propagation of Macrocarpium officinalis.The results of our research demonstrate that: 1.Grafting of Macrocarpium officinalis (1). improved bud grafting has the higher survival rate than any other grafting methods. it could be as high as 80.7% and worth of being popularized. (2)During the process of improved bud grafting, the optimist time for collecting scions is from the end of February to the beginning of March; time for grafting is from the end of March to the beginning of April; 2a reserved seedlings are chosen as stock trees and 1a branches as grafts; the optimist length of cut buds is around 2.5₃.0cm, width 0.5cm, the area of the surface of cut bud 1.3-1.5cm2; favorable binding method is whole-bud-binding( bud is fully covered). With all these prerequisites being met , the survival rate can be improved substantially. (3)During the process of grafting, the optimist diameter of scion is 0.4-0.6cm and the optimist time for unbinding buds is 30days after grafting. 2. laying propagation of Macrocarpium officinalis: (1)With double circular incision at 10 cm above the base of the stalk and reserving 0.5-1 cm stem next to main stalk when clipping shoots at the base of stalk, the number of germinating shoots can be increased by 100% and 89% respectively. (2)In layering techniques, the number of roots formed can be increased by 57% if double circular incision conducted at the location from which roots of newly germinating shoots form 10-20cm thick covering soil facilitates 2.75 times of the roots forming at 10cm thick covering soil. one –year-shoots produce roots more easily, they can produce 10 more roots(30%) each than 2-year-shoots. So efficiency can be improved by stressing cultivating one-year-shoots and making more use of one year shoots. (3)As for the method of plantation of parental trees, we got the highest rate of seedling formation from deep-hole-shallow-planting method, the rate is as high as 93% and the average number of roots formed per shoot is 31 and the biggest too; 83% and 18 for big-hole-shallow-planting and 65% and 18 for ordinary planting respectively. So deep-hole-shallow-planting is advised in planting parental trees. 3. cutting propagation of Macrocarpium officinalis: (1)Macrocarpium officinalis is a difficult type of tree species and under the current test conditions, it is almost impossible to use rough branches for cutting propagation. (2)Cutting propagation with young branches doesn't produce good result either, the survival rate is only 30%. (3)It is advised to improve test methods in order to increase the survival rate of cutting propagation. It is concluded from the statement above that the grafting and layering techniques suggested in the article can be popularized in the plantation of Macrocarpium officinalis while for cutting propagation of Macrocarpium officinalis further study is needed.