Effects of water extracts of Flaveria bidentis on the seed germination and seedling growth of three plants.

To further explore the mechanism behind the allelopathic effects of Flaveria bidentis, we investigated the allelopathic effects of water extracts from Flaveria bidentis leaves on three plants, Shanghai green, barnyard grass and wheat. The results showed that the water extracts inhibited the germination potential, germination rate, seedling height, root length, chlorophyll content, fresh weight and dry weight of the three plants, and increasing the extract concentration further increased the inhibitory effect. The allelopathic effects of the water extracts from Flaveria bidentis leaves on the three receptor plants differed in strength from strong to weak as follows: Shanghai green > barnyard grass > wheat. Thus, wheat had strong resistance to the allelopathic effects of Flaveria bidentis and could be planted in area where Flaveria bidentis occurs. The effect of the water extract from Flaveria bidentis leaves on the seed germination and seedling growth of barnyard grass was obvious; thus, this extract could be used for the biological control of barnyard grass.

Isolation and identification of a 10-deacetyl baccatin-III-producing endophyte from Taxus wallichiana.

Endophytic fungi of inner root bark of Taxus wallichiana var. mairei were investigated in order to find endophytes producing 10-DABIII (10-deacetyl baccatin III). Purified colonies were cultured in potato dextrose broth (PDB), and then the organic extracts from fungi were analyzed with HPLC, LC-MS, and (1)H NMR. Of 102 fungal endophytes isolated from the inner root bark, only one strain named IRB54 can yield 10-DABIII but no taxol and baccatin III. In PDB culture medium, its productivity was 187.564 ug/l. Based on its morphological characteristics and molecular data, the IRB54 strain was identified as Trichoderma sp. The isolation of the fungus IRB54 yielding 10-DABIII will provide an alternative resource to manufacture taxol/taxotere via semi-synthesis and some useful clues for improving the understanding of taxane synthesis evolution.

Genetic and component content differentiation between wild and cultivated populations of Paeonia lactiflora and related species used as Chishao and Baishao in China.

One hundred and forty-four samples of Chishao and Baishao, which represented six species of Paeonia L. were evaluated for their genetic variation, genetic differentiation and phylogenetic relationship, based on the nuclear ribosomal DNA internal transcribed spacer (ITS) region. Samples from representative of the population were then used to do a cultivation comparison experiment, and then to identify the contents of the active ingredients. The results showed there were differences in the haplotype distribution and frequency between populations of Chishao and Baishao. An analysis of molecular variance (AMOVA) indicated statistically significant (p<0.001) genetic differentiation between the populations of wild and cultivated Paeonia lactiflora PALL. The albiflorin content between Chishao and Baishao was also significantly different (p<0.05). All the results clearly illustrate that currently cultivated P. lactiflora cannot be used as a substitute for Chishao.

Selection for high oridonin yield in the Chinese medicinal plant Isodon (Lamiaceae) using a combined phylogenetics and population genetics approach.

Oridonin is a diterpenoid with anti-cancer activity that occurs in the Chinese medicinal plant Isodon rubescens and some related species. While the bioactivity of oridonin has been well studied, the extent of natural variation in the production of this compound is poorly known. This study characterizes natural variation in oridonin production in order to guide selection of populations of Isodon with highest oridonin yield. Different populations of I. rubescens and related species were collected in China, and their offspring were grown in a greenhouse. Samples were examined for oridonin content, genotyped using 11 microsatellites, and representatives were sequenced for three phylogenetic markers (ITS, rps16, trnL-trnF). Oridonin production was mapped on a molecular phylogeny of the genus Isodon using samples from each population as well as previously published Genbank sequences. Oridonin has been reported in 12 out of 74 species of Isodon examined for diterpenoids, and the phylogeny indicates that oridonin production has arisen at least three times in the genus. Oridonin production was surprisingly consistent between wild-collected parents and greenhouse-grown offspring, despite evidence of gene flow between oridonin-producing and non-producing populations of Isodon. Additionally, microsatellite genetic distance between individuals was significantly correlated with chemical distance in both parents and offspring. Neither heritability nor correlation with genetic distance were significant when the comparison was restricted to only populations of I. rubescens, but this result should be corroborated using additional samples. Based on these results, future screening of Isodon populations for oridonin yield should initially prioritize a broad survey of all species known to produce oridonin, rather than focusing on multiple populations of one species, such as I. rubescens. Of the samples examined here, I. rubescens or I. japonicus from Henan province would provide the best source of oridonin.

[Determination of mineral elements utilization of Paeonia lactiflora Pall by ICP-AES].

The contents of K, Ca, Na, Mg, Fe, Cu and so on in the roots of Paeonia lactiflora Pall and in the soil in which they grew were determined by ICP-AES technique to study the mineral elements utilization of P. lactiflora Pall. The results indicate that the elements utilization rate of P. lactiflora Pall is different in different locations, so the contents of mineral elements in the roots of P. lactiflora Pall and even the quality of medicinal materials coming from them in different locations are different. The contents of Ca, Fe, Zn and so on in Chi Shao in Heilongjiang and Inner Mongolia are relatively high. The contents of mineral elements in soil influence not only themselves' utilization but also other mineral elements utilization of P. lactiflora Pall.

[Comparative research on pharmacognostic characteristics and microscopic characteristics of Radix Paeoniae Rubra from different areas].

OBJECTIVE: To compare pharmacognostic characteristics and microscopic characteristics of Radix Paeoniae Rubra (chishao) from different areas. METHOD: Pharmacognostic characteristics and microscopic characteristics of Radix Paeoniae Rubra were compared by microscope count methods. RESULT: Chishao in duolun was more straighter and longer, cortex with a set of closely spaced rill, peel off easily, pink section, etc. The wild chishao were different from the cultivated chishao on pharmacognostic characteristics and microscopic characteristics, such as appearance shape, smell, vessel arrangement, and number of crystal and starch in unit area. CONCLUSION: Chishao in duolun were different form others, appearance shape, wood fiber, difference of appearance shape, vessel arrangement, and number of crystal and starch in unit area can be used as identificatin feature of the wild chishao and the cultivated chishao.

[RP-HPLC determination of main chemical components in different parts and different harvest periods of Paeonia lactiflora].

The contents of gallic acid, catechin, albiflorin, paeoniflorin, benzoic acid and paeonol extracted in different growth years, collecting season and of different parts of Paeonia lactiflora were determined. The results showed that the contents of catechin and paeoniflorin in Paeonia lactiflora collected in autumn are the highest, and the contents of benzoic acid was lower than that of those collected at other time. The longer is the age of Paeonia lactiflora, the higher is the contents of catechin and paeoniflorin. The contents of catechin and paeoniflorin in the root of Paeonia lactiflora were higher than those in other parts of the plant. There is a certain content of paeoniflorin in the leaves of Paeonia lactiflora. Judging from the result, paeoniflorin is synthesized in the leaf and then transported to the root. Catechin is not synthesized in the leaf, but mainly in the root. Paeonia lactiflora should be collected in autumn, and immature plant should not be collected.