Viability of 7 kinds of medicinal plant seeds stored in medium-term gene bank of the National Medicinal Plant Gene Bank / 中国中药杂志

In order to evaluate seed viability of Platycodon grandiflorum, Schizonepeta tenuifolia, Andrographis paniculat, Codonopsis pilosula, Scutellaria baicalensis, Leonurus japonicus, Rabdosia rubescens, stored in the medium-term gene bank of the National Medicinal Plant Gene Bank for 4 years, we tested seed germination rate of 7 species of medicinal plant and analyzed the change of significance of levels of the germination rate in pre and post store. Seed germination rates of 7 species of medicinal plants were all decreased after 4 years, and the decrease of S. tenuifolia and S. baicalensis germination rates were much smaller than other species. The higher initial germination rate of P. grandiflorum, C. pilosula, R. rubescens seed has the smaller decline of germination rate, but the data of A. paniculata showed the opposite trend. The rate decline of the germination of S. tenuifolia and S. baicalensis was roughly the same in different germination rate interval. The results showed that low temperature storage could effectively prolong the seed longevity, and maintain the seed vigor. Moreover, it is necessary to study on the storage characteristics of the main medicinal plant seeds, and establish the monitoring plan and regeneration standard.

Variation and correlation analysis on phenotypic traits of Scutellaria baicalensis from different strains / 中国中药杂志

To research the differences and correlation between Scutellaria baicalensis about phenotypic traits of different strains, 10 aboveground traits and 6 root traits of S. baicalensis in two-year-transplanted plants from 14 different strains were compared respectively, and the SPSS 17.0 statistical software was used for data analysis. It showed that phenotypic traits variation of different S. baicalensis strains was rich and the F value ranged from 3.169 to 71.58. The difference was significant between each other and germplasm 15 performs the most outstanding characters. Correlation analysis showed that there existed a significant correlation between the characters except for lateral root number, root diameter and length. The correlation coefficient between the fresh weight of root and the reed head diameter was up to 0.877. Principal component analysis showed that the average of overall yield per plant and root diameter could be used as the comprehensive reference index for germplasm evaluation. The differences and correlations in phenotypic traits of different S. baicalensis strains, provide theoretical basis for distinguishing germplasm and breeding good varieties of S. baicalensis.

Establishment of a cell suspension culture system of endangered Aquilaria sinensis (Lour.) Gilg / 药学学报

Aquilaria sinensis callus induced by stem tips were used to establish the suspension cell system. The results showed that the most suitable medium for callus induction and subculture is MS + 2.0 mg x L(-1) NAA + 1.0 mg x L(-1) 6-BA. After 12 times of subculture, the energetic and loose callus, which were appropriate for cell suspension culture, were cultured and shook in liquid medium MS + 2.0 mg x L(-1) NAA + 1.0 mg x L(-1) 6-BA + 500.0 mg x L(-1) casein hydrolysate (CH) to establish the suspension cell system. The growth curve of suspension cells showed a "S" type. At the beginning of the culture, cell density increased slowly; during 4 to 6 days, suspension cells reached logarithmic growth period; during 7 to 12 days, suspension cells were in the platform period; but after 12 days, cell density and activity went down obviously. Agarwood sesquiterpenes were not detected in the suspension cells during the growth period, however, they could be detected in MeJA treated suspension cells. In this study, a stable and active growing suspension cell system was established, which was a proper system to study the mechanism of agarwood sesquiterpene formation, and additionally provided a potential way to generate agarwood sesquiterpenes through application of cell culture.

Studies on high efficient plant regeneration system from anther callus of Bupleurum chinense / 中国中药杂志

The callus of Bupleurum chinense with anthers at the stage of uninucleate was induced. After several subcultures, anther calli of B. chinense were cultured at 20 MS culture mediums with different plant hormones to differentiate into plantlets. Differentiation of callus was detected after 21 and 49 days to select the most effective medium. There were 19 culture mediums in which anther callus could differentiate into plantlets with differentiation rate range from 3% to 60% , and most less than 20%. MS + KT 0.5 mg x L(-1) + sucrose 30 g c L(-1) + phytagel 5 g x L(-1) was the best differentiation medium with the differentiation rate of 60%, followed by MS + ZT 1.0 mg x L(-1) + sucrose 30 g x L(-1) + phytagel 5 g x L(-1) with the differentiation rate of 58%. Then plantlets were transferred to rooting medium to obtain whole plant. All plantlets could root in the rooting medium of MS + sucrose 30 g x L(-1) + phytagel 5 g x L(-1) and 1/2 MS + NAA 0.5 mg x L(-1) + sucrose 30 g x L(-1) + phytagel of 5 g L(-1) with the rooting rate of 100%. As a result, the high efficient and stable plant regeneration system was established from anther callus of B. chinense.

Isolation and identification of pathogen of seedling blight of Platycodon grandiflorum / 中国中药杂志

<p><b>OBJECTIVE</b>To isolate and identify pathogen of the seedling blight occurred in Platycodon grandiflorum.</p><p><b>METHOD</b>The morphological observation, rDNA ITS sequence analysis, and Koch's postulates were used to identify the isolates of the causal agent.</p><p><b>RESULT</b>The isolates of the causal agent was Rhizoctonia solani.</p><p><b>CONCLUSION</b>The result confirmed that R. solani is the pathogen of seedling blight of P. grandiflorum.</p>

Observation of pollen tube germination of Platycodon grandiflorum by fluorescence microscopy / 中国中药杂志

<p><b>OBJECTIVE</b>To determine the self-compatibility of Platycodon grandiflorum and the location of microspore germination on stigma.</p><p><b>METHOD</b>The microspore germination of self-pollination, self-plant-pollination and cross-pollination and the pollination microspore germination in and outside of stigma were observed with fluorescence microscopy.</p><p><b>RESULT</b>Most pollens of self-pollination, self-plant-pollination and cross-pollination can germinate on the stigma, and after 24 hours, pollen tube entered into the ovary successfully. Pollinated on the outer-surface of stigma, microspores could not germinate, but on the inner-surface of the stigma when it dehisced most microspores can germinate.</p><p><b>CONCLUSION</b>The compatibility of self-plant-pollination of Platycodon grandiflorum is high. The microspore germination loci is on the inner-surface of the dehisced stigma.</p>

Study on the stigma/pollen vigor and self-compatibility of Platycodon grandiflorum / 中国中药杂志

<p><b>OBJECTIVE</b>To provide the basal data for the breeding and cultivation of Platycodon grandiflorum.</p><p><b>METHOD</b>The field investigation and pollination by bagging were carried out. TTC(2,3,5-triphenyl tetrazolium chloride) solution was used to test the pollen vigor.</p><p><b>RESULT</b>The stigma life-span of P. grandiflorum was about 9 days, however the optimal time for pollination is 4-6 days after the petals opening, with the stigma was splitting lightly or significantly. When the petals opened, the anther began scattering pollen, and finished in the same day. The pollen vigor was about 81.4% at the beginning, and decreases to 27.6% three days later. The pollen vigor still remains 64.4% three days later, when the flower was kept in the desiccant. The natural fructification rate of self-flower-pollination was 4.8%. The fructification rate and compatible index was about 62.7% and 54.6, respectively, when the self-plant-pollination performed by hand. They decreased to 12.8% and 6.5 when the pollination was implemented during the flowering period.</p><p><b>CONCLUSION</b>Low fructification percentage of self-flower-pollination attributes to the difference of maturing period of pistil and stamen, as well as the short pollen life-span of P. grandiflorum. The compatibility of self-plant-pollination is high during flowering period when pollination performed by hand. The life-span of the pollen can be prolonged significantly when keeping in the dry environment.</p>