[Discrimination of cultivation modes of Dendrobium nobile based on content of mineral elements and ratios of nitrogen stable isotopes].

This study explored the feasibility of mineral element content and ratios of nitrogen isotopes to discriminate the cultivation mode of Dendrobium nobile in order to provide theoretical support for the discrimination of the cultivation mode of D. nobile. The content of 11 mineral elements(N, K, Ca, P, Mg, Na, Fe, Cu, Zn, Mn, and B) and nitrogen isotope ratios in D. nobile and its substrate samples in three cultivation methods(greenhouse cultivation, tree-attached cultivation, and stone-attached cultivation) were determined. According to the analysis of variance, principal component analysis, and stepwise discriminant analysis, the samples of different cultivation types were classified. The results showed that the nitrogen isotope ratios and the content of elements except for Zn were significantly different among different cultivation types of D. nobile(P<0.05). The results of correlation analysis showed that the nitrogen isotope ratios, mineral element content, and effective component content in D. nobile were correlated with the nitrogen isotope ratio and mineral element content in the corresponding substrate samples to varying degrees. Principal component analysis can preliminarily classify the samples of D. nobile, but some samples overlapped. Through stepwise discriminant analysis, six indicators, including δ~(15)N, K, Cu, P, Na, and Ca, were screened out, which could be used to establish the discriminant model of D. nobile cultivation methods, and the overall correct discrimination rates after back-substitution test, cross-check, and external validation were all 100%. Therefore, nitrogen isotope ratios and mineral element fingerprints combined with multivariate statistical analysis could effectively discriminate the cultivation types of D. nobile. The results of this study provide a new method for the identification of the cultivation type and production area of D. nobile and an experimental basis for the quality evaluation and quality control of D. nobile.

[Content of mineral elements of Gastrodia elata by principal components analysis].

OBJECTIVE: To study the content of mineral elements and the principal components in Gastrodia elata. METHOD: Mineral elements were determined by ICP and the data was analyzed by SPSS. RESULT: K element has the highest content-and the average content was 15.31 g x kg(-1). The average content of N element was 8.99 g x kg(-1), followed by K element. The coefficient of variation of K and N was small, but the Mn was the biggest with 51.39%. The highly significant positive correlation was found among N, P and K . Three principal components were selected by principal components analysis to evaluate the quality of G. elata. P, B, N, K, Cu, Mn, Fe and Mg were the characteristic elements of G. elata. CONCLUSION: The content of K and N elements was higher and relatively stable. The variation of Mn content was biggest. The quality of G. elata in Guizhou and Yunnan was better from the perspective of mineral elements.

[Effects of Different Planting Direction and Layer Combination on Gastrodia elata f. elata in Bionic Wild Cultivation].

OBJECTIVE: Combination of different planting direction and layer were set to choose the best technology of cultivation of Gastrodia elata f. elata. METHODS: To improve the yield and quality of Gastrodia elata f. elata, randomized block design experiments were carried out to investigate the yield and quality, and to analyze their economic effectiveness in bionic wild cultivation. RESULTS: Length, width, thickness and weight of southern direction's Gastrodia elata f. elata developed better than the northeast direction. The three planting layer levels on growth effect of Gastrodia elata f. elata was the 3rd layer > the 2nd layer > the 1st layer. In six treatments, combination of southern direction-the 3rd layer was the best technology of cultivation of Gastrodia elata f. elata, which had the best growth condition, the highest yield significantly higher than other treatments, and the best economic benefits. CONCLUSION: Southern direction associated with the 3rd layer is the best combination to planting Gastrodia elata f. elata in bionic wild cultivation. The planting ways not only improve the yield and quality, but also save land.

[Research on life history and phenological period of wild-stimulated cultivated Gastrodia elata f. elata in Guizhou].

In order to get to know the imitation of wild Gastrodia elata in life history and phenology period, by G. elata f. elata forest wild simulated cultivation in Dafang county, Guizhou province, observing and recording its morphological characteristics of each growth and development stage. This experiment summarized the law of its life history over 24 months, amplified the characteristics of each 5 phenology periods over the sexual and asexual reproduction of wild simulated cultivated G. elata f. elata in Guizhou. Which the results could clear the process of wild simulated cultivated G. elata f. elata in Guizhou, and provide a theoretical support for the standard technical of the simulated wild G. elata.

[Study on germination characteristics of Disporum cantoniense].

OBJECTIVE: To study the seed germination characteristic and optimal germination condition of wild Disporum cantoniense. METHODS: Used wild Disporum cantoniense seed as the test materials, the rate of water absorption of the seed was determined. The germination rates under different conditions, along a temperature gradient (15, 20, 25 and 30 degres C), in light or dark, on top or between wet filter papers, and keeping or removing the seed coat, were determined respectively using petri dish method. At the same time germination trends were observed. RESULTS: The thousand seed weight was 33.24 g, and the seed water-absorbing reached saturation pot after soaking for 30 h. Higher germination rates were respectively recorded at 25 degrees C, between filter papers, and in dark after 24 h soaking in the pretreatment solution. CONCLUSION: The optimal condition for the germination of the seed of wild Disporum cantoniense is as follow: keeping testa, seed soaking for 24 h in seed germination agent and being incubated between wet filter papers in dark at 25 degrees C.

[Study on endogenesis inhibitory substances in seed of Thesium chinense].

OBJECTIVE: To investigate the activity and the location of the endogenesis inhibitory substances in seed of of Thesium chinense. METHOD: The rough extracts from different concentrations, places and extracting times of T. chinense seeds were prepared and determined by its effect on wheat and Brassica sp seed. RESULT AND CONCLUSION: The extract dramatically inhibited the germentation and the growth of wheat and Brassica sp seed and the inhibitory activity was positively related to the concentration of the extracts. When the concentration reached 0. 32 g mL(-1), wheat seed did not germentate. With increasing the extracting times, the inhibitory activity first decreased, then increased. The capsule and kernel both had inhibitory substances and the latter was stronger than the former. Highly active inhibitory substances were found first time in the seed of T. chinense.