Breeding Technique Research In Rare And Endangered Species Of Parashorea Chinensis

In this paper, the rare and endangered specie Parashorea chinensis was chosen as the object of experiment. Systematic research was done on both aspects of seed nursery and the cutting propagation. Furthermore, search for a scientific and efficient system of breeding in order to lay the technique foundation for enlarge the population of the rare specie resource. It is of significant theoretic meaning on conducting the seedling production and the resource utilization of Parashorea chinensis. The results were shown as follow:1. Nutrition bag and directly sowing on seedling bed as well as the comparative seedling experiment among seeds of different grain level were applied. The results shows, there are relative big difference on the growth of seedlings varying from different grow seedling method. The average height, the ground diameter, the number of leaf per plant under the nutritive bags seedling treatment increased by12.0%、22.0%and11.5%respectively in comparison with the seedlings under the field seedbed planting treatment. The root morphological indexes of nutritive bags seedlings were greater than that of the field seedbed planting seedlings. The average number of lateral root in nutritive bags seedling reached to22.5per plant and increased by63.5%in comparison with the field sowing seedlings. The average number of lateral root,the dry weight of underground growth part and the ratio of root to shoot was significantly different between the different raising seedling methods. There were significant differences between large seed and small seed,between middle seed and small seed in the seedling height,the basal diameter and the number of leaf,respectively, but no significant differences between large seed and middle seed in all the growth indexes. The way of seedling with nutritive bag was better than the method of field seedbed planting seedling. Nutritive bags were in favor of seedling’s height and diameter growth and the root system development. Raising seedling with nutritive bag would be an appropriate measure for cultivating the high quality seedlings and should be promoted in the production.2. It is shown through the research about the growth rhythm of the endangered plant Parashorea chinensis that the seedling growth model of this specie is of evident periodicity, presenting a trend approximately as fast-slow-fast-slow. The height and the ground diameter growth of Parashorea chinensis seedlings is basically the same as the S type growth regularity. The whole growth process can be divided into5growth periods that are emergence period, gradually increase period, slowly increase period, quickly increase period and seedling hardening period, the duration of quickly increase period can last for about184days. The growth of height and ground diameter during the quickly increase period account for41.68%and60.90%of the total growth, respectively. When fitting the growth of height and ground diameter into logistic equation, both the regression reached significant level. The optimal regression equation between height and diameter of seedlings and time was established.3. Three growth regulator, which are GGR, IBA and PP333, of different concentration were used to proceed the spray management in the experiment. The result shows, there are difference among influences of different managements on the growth of seedlings. It is the best for promoting the growth and enhancing the biological feature of Parashorea chinensis seedlings by spraying GGR40mg/L and IBA80mg/L4. The Parashorea chinensis seedlings planted in containers were applied with different amount combined fertilizer. The result shows, there are significant influence on height, ground diameter, branches number, the growth of root and the accumulation of biomass of different managements.1%management is the optimal strategy.5. Double layer shadowing net, single layer shadowing net and none-shadow managements are adopted to Parashorea chinensis seedlings planted in field. The result shows, there are extremely significant influences on the growth and quality of the seedlings of different shadow managements. Among which, the single layer shadowing net management is the best, with56.16%and73.79%higher of chlorophyll and soluble sugar than none-shadow management, respectively. Both over-shadow and completely exposure are bad for the growth of seedlings.6. The result of cutting propagation shows, spring is the best season for cutting. Plant growth regulators, which are GGR, NAA and IBA, of different concentration were applied. The result shows, the root striking quality of the cutting slips that applied GGR300mg/L is up to39.87%, higher than the rest managements. Six different type bulk material were added to the cutting slips of young trees’branches for a comparison experiment. The result shows, the root striking rate of the cutting slips added coconut powder is the highest, which reached66.7%. This means that coconut powder is an ideal bulk material. The root striking anatomy research of cutting slips indicates, the root striking type of Parashorea chinensis belongs to callus root striking type...