Effects Of N,P And K Fertilization On Growth, Yield And Quality Of Angelica Dahurica Var. Formosana From Sichuan Province And Its Drought Resistance During Seedling Stage And Pollination Biology

Angelica dahurica Radix is traditionally considered as one of the most common components of traditional Chinese medicine (TCM) prescriptions and widely used in the treatments of anemofrigid cold, headache and rheumatoid arthritis cold etc. Angelica dahurica Radix from Sichuan, the original plant is Angelica dahurica (Fisch. ex Hoffm.) Benth. et Hook. f. var. formosana (Boiss.) Shan et Yuan, mainly distributes in Suining, Anyue, Daxian, Nanchong and other regions of Sichuan Province. A. dahurica var. formosana cultivated particularly in Suining has a long history and the largest output in China. Using A. dahurica var. formosana from Sichuan Province as the experimental material, this paper studied the growth characteristics, nutrient accumulation rule, yield and quality and the influence function of the fertilization ratio of N, P and K on A. dahurica var. formosana at vegetable growth period in order to provide theoretical basis for making up proper fertilization method. Meanwhile, this experiment intended to study the optimum conditions of simulated drought stress, and screen the indexes of drought resistance and comprehensively assess the drought resistance of the A. dahurica resources during seedling stage, under polyethylene glycol (PEG-6000)-simulated drought stress. We attempet to reveal the characteristic of the pollination biology, and discussed the effect of pollination mechanism to reproduction and development of A. dahurica var. formosana from Sichuan.The main results are as follows:1. According to the growth changing rule of the aerial parts and roots, the assimilation and accumulation of nutrients, the vegetative growth period of autumn sowing A. dahurica var. formosana from Sichuan Province can be preliminarily divided into three phases:seedling period (emergence-the late February), aerial-part peak growth period (the late February the middle of May) and root peak growth period (the end of April-the late July). In aerial-part peak growth period, the plant height and aerial part dry weight increased obviously. In root peak growth period, the growth center changed into underground part. The root diameter grew rapidly, at the same time the accumulation rate of root dry weight, N, P, K and the content of imperatorin and isoimperatorin increased obviously.2. The correlation analysis results showed that the plant height had positive correlation with aerial part dry weight and root length, aerial part dry-weight showed positive correlation with root length, and there were positive correlation among root length, root diameter and root dry weight. The correlation analysis results showed that the concentration of N in aerial part had negative correlation with the contents of imperatorin in root. But the accumulation of K in aerial part and the accumulation of N, P and K in root had positive correlation with root dry weight, the accumulation of P and K in aerial part had positive correlation with the concentration of imperatorin in root, and the correlation analysis results also showed that the accumulation of N, P and K in root had positive correlation with the concentration of isoimperatorin in root.3. The order of total nutrition accumulation was N> P> K, the accumulation of N, P and K in aerial part decreased gradually during the growth period, but the accumulation of N, P and K in root increased gradually. Application amount of P fertilizer was lower compared with N, K fertilizer. A part of N, P, and K fertilizer could be applied as base fertilizer and the other as top dressing. The time of dressing N fertilizer was earlier than P, K fertilizer. From late April, A. dahurica var. formosana from Sichuan Province entered root peak growth period and balanced application of fertilizer should be considered.4. Application of N, P and K at an appropriate rate and ratio enhanced root length, root diameter, and dry matter accumulation. The vigorous growth periods of aerial part could be extended at most treatments, and treatment 4 (N 10kg/667m2, P2O5 15kg/667m2, K2O 8kg/667m2, namely, the ratio of N:P2O5:K2O is 1.5:1:1) was the most significant among the 9 treatments. N fertilizer had the most effect on plant height and dry matter accumulation. And P fertilizer had the most effect on root length and root diameter.5. The influences of different treatments on the concentration and accumulation of N, Pand K were different. The law of N, P and K accumulation was similar with dry matter accumulation. There was a little difference among different treatments in prophase. With the increase of accumulation of N, P and K, the difference increased gradually from late April. N fertilizer had significant effect on the concentration of N, Pand K in aerial part and root, the accumulation of P, K in aerial part and the accumulation of N, P and K in root. P fertilizer had significant effect on the concentration of N in root, the accumulation of N, P and K in aerial part and root. K fertilizer had significant effect on the concentration of N, P and K in aerial part the concentration of N and K in root, the accumulation of P in aerial part and the accumulation of N, P and K in root.6. The yield of A.dahurica var. formosana from Sichuan Province was extremely affected by N, P and K combined application. And 9 different treatments increased the yield of A. dahurica var. formosana from Sichuan Province. Among different N, P and K treatments, the yield of treatment 6 (N 10kg/667m2, P2O5 15kg/667m2, K2O 8kg/667m2, the ratio of N: P2O5:K2O is 1.5:1:1.) was the highest. The orthogonal analysis of variance results showed that P fertilizer had the greatest effect on the yield (P<0.01), followed by N fertilizer (P<0.05), and K fertilizer had the least effect, which did not reached significantly different level (P>0.05).7. The influences of different treatments on the quality of A. dahurica var. formosana from Sichuan Province were different. Application of N P and K at an appropriate rate and ratio enhanced the content of imperatorin and soimperatorin. The influence of N, P and K fertilizer on imperatorin all reached extremely significantly different level (P<0.01). Of them, the effect of P and K fertilizer was higher than that of N fertilizer. But only N fertilizer had significant influence on the contents of isoimperatorin (P<0.05).8. Drought stress of 9 days with 20% PEG was the optimum condition of simulated drought stress. The results showed that the drought resistant capability decreased in the order as follows, A. dahurica var. formosana from Sichuan Province, A. dahurica from Henan Province, A. dahurica from Hebei Province and A. dahurica var. formosana from Zhejiang Province. And the order of correlative degree of drought ressistance and indexes was:soluble sugar>root length>proline>root-shoot ration>total content of chlorophyll> chlorophyll b>chlorophyll a>height>malondialdehyd. Osmotic adjustment substance and the indexes related to the root had more influence on the drought resistance of A. dahurica during seedling stage. A. dahurica var. formosana from Sichuan Province had the highest drought resistance during seedling stage.9. Bases on field fixed plants observations and artificial pollination experiments, this paper studied the floweing phenology of the floral biology, pollination process and breeding characters of A. dahurica. The results showed that the blooming time lasted about 30 days, from the middle and last the day of May to the early of July, while the florescence of a single flower is only lto 2 days.The results indicated that no apomixis occurred, the breeding system was outcrossing with self-compatibility and pollinators were needed based on the results of emasculation, bagging and artificial pollination studies. The most frequent floral visitors were bees and flies, and the peak time of pollinator visits was 9:00-15:00.