Study On Seed Characteristics And Seedling Growth Of Archidendron Clypearia

Archidendron clypearia(Jack) Nielsen is an important traditional Chinese medical(TCM) plant and belongs to the family Mimosaceae. In China, it is mainly distributed in the southern provinces of Zhejiang, Fujian, Guangdong, Guangxi, Yunnan and Taiwan provinces with an extreme low population density. The wild resource of the species has become depleted owing to the long-standing overexploitation. Plantation development seems to be the only means for securing the supply of raw materials for the sustainable development of the TCM products of this species. However, little is known about the characteristics of the seed and seedling growth performance of this species and the standard operating procedure(SOP) required for the cultivation of this TCM plant is still lacking. This paper reports results obtained from a series of studies on seed morphology, germination characteristics, early growth performance of seedlings and their response to fertilization as well as on their stoichiometry of the species.Seed weight, and morphological and germination characteristics were examined on 17 families of 5 provenances of A. clypearia collected from Guangdong Province. Results showed that differences in the seed length, width, thickness, fresh weight and germination rates were significant between the provenances. Seed length variation amplitude 11.13 mm~13.86 mm, seeds from a wide range 9.19 mm to 10.75 mm, seed thickness 7.02 mm~8.73 mm, grain weight of 577 g~876 g, the coefficient of variation for each morphological index reaches significant levels. Among them, the seeds appearance of Huizhou region collected the best, followed by Liuxi River, Dalingshan provenances. Beginning of germination was not significantly different in 6 sources, both five days, indicating that A. clypearia a rapid seed germination, not experience dormancy; high germination rate was Liangkou, Liuxi River, Dalingshan provenance; germination potential was no significant difference between the provenances. Zengcheng seeds were collected the earliest, and the maturity is not enough, which impact its germination characteristics, so the seeds should be naturally matured, which for seed germination and seedling later growth was important.A. clypearia seeds were moderate recalcitrant seeds. It's completely inactivated at-17 ?. 5 ? can be stored for some time. Three levels of A. clypearia seed moisture content was no significant difference. Germination rate and index change basically the same at different temperatures. After a month in storage under 5 ? and 25 ?, the germination rate and germination potential change little. It was found that the seeds stored at room temperature, there is mildew, and stored at 5 ? condition of almost no mildew appears,therefore Archidendron clypearia seeds appropriately stored at 5 ?, low mildew and a higher germination rate potential. It can be further attempts to extend the storage time at this temperature.There were significant differences in the seedling growth of different A. clypearia provenances. The seedling growth of Liuxi River, Huizhou provenance was significantly better than other kinds of sources, performed better in diameter, height and biomass, seeds of Zengcheng provenance is not mature enough at the time of collection, which effects its later growth, so their performance is relatively poor; Hainan provenance grows slowly, when the temperature becomes higher in spring, the growth rate significantly accelerated. That maybe Hainan seeds can not apply to the low temperature in Guangzhou. After sowing, the seeds cannot grow normally affected by low temperatures, until the temperature is high, the seedlings began to grow rapidly. So Hainan seeds should pay attention to the temperature regulation when cultivation.In the early seedling fertilization experiments, we conducted two programs, N, P, K orthogonal design and P fertilizer single test, the results showed consistency. The orthogonal fertilization optimal treatment was N 20 mg, phosphate 20 mg, K fertilizer 0 mg. In factor levels for multiple comparison, P fertilizer Level 1 and Level 2 was not significantly different, but the level 1 amount is zero, without the application of P fertilizer, so the early seedlings growth just need the right amount of N fertilizer, but for P and K are not lacking; a single application of P fertilizer tests showed no P fertilizer seedling growth performed better than the other treatments applied P fertilizer, and some of the conclusions were consistent to the orthogonal fertilization. Therefore, according to the principles of economic fertilization, early seedling growth right amount of N fertilizer applied, without application of P and K fertilizer.Determination of nutrients for seedlings, draw Archidendron clypearia average carbon content in the leaves of 476.81 mg / g, indicating a high storage capacity C; C: N ratio of 23.06, indicating its N with high efficiency; C: P is 188.03,a low utilization efficiency on P; N: P 8.20, may be considered seedling growth is limited by the N. Although seedlings under N-limited, but you can see, C: N ratio is higher, indicating that their growth restriction element plant efficiency will be higher, reflecting the kind of plant responses to environmental adaptation.