A revision of Dryopteris sect.Diclisodon(Dryopteridaceae)based on morphological and molecular evidence with description of a new species

Dryopteris sect.Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia.Here,we carried out morphological and phylogenetic analyses of this section.A new species from southwest China,D.gaoligongensis,is described and illustrated.Dryopteris gaoligongensis resembles D.indonesiana and D.sparsa,but differs by having a creeping rhizome and large 4-pinnate fronds.We also show that D.glabrior Ching&Z.Y.Liu is a distinct species;however,because it is a later homonym of D.glabrior Copel.,it should be renamed D.renchangiana.We conclude that a species previously known as D.nitidula,also an illegitimate homonym,should be recognized with a new name,D.sinonepalensis.We resolve the phylogenetic position of D.yoroii as sister to other sampled species of D.sect Diclisodon.Our phylogenetic analyses confirm the distinctiveness of D.gaoligongensis,D.renchangiana,and D.sinonepalensis.A key to species of D.sect Diclisodon in China is provided.

中国东北古新世乌云植物群:Woodwardia bureiensis,Dryopteris sp.和Osmunda sachalinensis(英文)

在黑龙江省嘉荫县乌云镇古新世乌云植物群中新发现的Woodwardia bureiensis Fedotov、Dryopteris sp.和Osmunda sachalinensis Krysht.在中国也是新记录。Woodwardia bureiensis与其他种的主要区别是小羽片排列紧密且边缘彼此靠合。Osmunda sachalinensis小羽片基部宽楔,而以前乌云植物群所报道的O.greenlandica(Heer)Brown小羽片基部平展。

Changes of the Microtubule Arrays During Mitosis in Prothallus Cells of Dryopteris crassirhizoma

Microtubule arrays in prothalli large-vacuolated and meristematic dividing cells of the fern Dryopteris crassirhizoma Nakai were studied using Steedman's wax, indirect immunofluorescence labelling and confocal laser scanning microscopy. Results showed that the use of high paraformaldehyde concentration (8%) allowed good fixation of prothallus cells, which are characterized by numerous (meristematic cells) and big (large-vacuolated cells) vacuoles. Results also plead for the efficiency of Steedman's wax embedding method in: (1) avoiding excessive use of enzyme for digesting cell wall in the process of the microtubule cytoskeleton labelling, (2) minimizing the autofluorescence effect in cells through utilization of alcohol in sample dehydration, and (3) permitting a clear visualization of microtubule patterns during the cell mitosis. Steedman's wax, coupled with immunofluorescence labelling and confocal laser scanning microscopy techniques, allows a good investigation of cell division process in plants by using simple multicellular organisms such as fern prothalli.

Separation and Purification of Total Phloroglucinols in Dryopteris crassirhizoma with DM-130 Macroporous Adsorption Resin

To improve the purity of the total phloroglucinols from Dryopteris crassirhizoma extracts, the separation and purification conditions of the total phloroglucinols from Dryopteris crassirhizoma were studied with DM-130 macroporous adsorption resin in this study. Adsorption rate, elution rate and purity of the total phloroglucinols were used as indexes to investigate the adsorption and desorption capacity of the total phloroglucinols with DM-130 macroporous adsorption resin. Through the study, the optimum sample concentration of the total phloroglucinols and maximum sample volume were 1.5 mg·mL^-1 and 7 BV （210 mL）, respectively. The optimum desorption conditions were achieved by using 80% ethanol as desorption solvent at elution flow rate of 1.0 mL·min^-1. The result showed DM-130 macroporous adsorption resin performed effective adsorption and desorption. After purification, the purity of the total phloroglucinols increased by 11.5-fold.

A Comparative Study on Photosynthetic Characteristics of Dryopteris fragrans and Associated Plants in Wudalianchi City,Heilongjiang Province,China

While comparing photosynthetic characteristics of Dryopteris fragrans(L.) Schott to those of several commonly associated plants in its native community, coordination between D. fragrans and its environment was observed. The diurnal net photosynthetic rate(Pn) varied dramatically for all the plants studied. D. fragrans, Woodsia ilvensis and Urtica angustifolia all exhibited unimodal type Pn variation, with low Pn, weak photosynthetic capacity, and dramatic maximal photosynthesis(Pmax) changes. When compared to values for its associated plants, D. fragrans values were of intermediate level, indicating difficulty in adapting to its environment. Moreover, the nitrate reductase activity of D. fragrans was higher than that of only one species, Artemisia gmelinii. With increasing leaf maturity and chlorophyll content, D. fragrans exhibited declining LCP(light compensation point) and a relatively low LSP(light saturation point). Because of its overall relatively weak photosynthetic capacity, D. fragrans exhibited narrow ecological amplitude with respect to light adaptation.

鳞毛蕨(Dryopteris filix-mas)天山云杉林倒木更新分析

对西天山国家级自然保护区1 hm2典型鳞毛蕨天山云杉林临时标准地内,倒木对更新的影响进行了研究。结果表明:①研究区中所有倒木的平均倾倒方向为西北方向,具有更新个体存在的倒木平均倾倒方向为东北方向;②倒木的倾倒方向对倒木的更新没有显著影响(F3,51=0.645,P=0.589),而倒木的腐朽等级对倒木的更新存在显著影响(F2,51=3.215,P=0.048);③不同腐朽等级倒木上幼苗、幼树的出现概率不同,能为幼苗、幼树生长提供生境的倒木只有腐朽等级高的Ⅲ,Ⅳ,Ⅴ级倒木,且倒木腐朽等级越高,对幼苗、幼树的生长越有利。

Ultrastructure of Oogenesis in Dryopteris crassirhizoma Nakai

Abstract: The ultrastructure of oogenesis in Dryopteris crassirhizoma Nakai has been investigated using transmission electron microscopy. The nucleus in the young egg is rounded with an uneven outline. As it develops, it becomes amoeboid and extends nuclear protrusions that are not only sac-like nuclear evaginations like those often seen in the oogenesis of other ferns, but also mushroom-like and finger-like, with an opening at their end allowing the nucleolus material to flow out from the openings. This has not been observed previously. The nuclear protrusions differ from Dryopteris filix-mas (L.) Schott. in the absence of sheets of nuclear membrane in the form of a closed ring. As the egg matures, the nucleus transforms into a tuber-like structure with a smooth surface, lying transversely in the egg cell. In the immature egg, vesicles almost encircle the nucleus twice and are most remarkable. In the maturing egg, the vesicles are distributed at the periphery, except for at the top of the egg, and affect the formation of the separation cavity and extra egg membrane. Simultaneously, vesicles from the venter canal cell move to the egg and take part in the formation of separation cavity and extra egg membrane. In the mature egg, a large number of small vesicles containing fragments of lamellae or osmiophilic material emerge from the cytoplasm. The origin of these vesicles is obscure. Irregular plastids containing a cylindrical starch grain dedifferentiated progressively. Mitochondria seem to have been undeveloped during the process, but return to normal at later stages of oogenesis. There is a high frequency of ribosomes in the mature egg. Microtubules, rarely seen in the eggs of D. filix-mas (L.) Schott. and Pteridium aquilinum (L.) Kuhn, have been observed inside the plasmalemma of the maturing egg in D. crassirhizoma.

Antifungal Activity of Aspidin BB from Dryopteris fragrans against Trichophyton rubrum Involved Inhibition of Ergosterol Biosynthesis

Objectives Aspidin BB, a typical phloroglucinol derivative from Dryopteris fragrans, possesses significant antifungal property. This study aimed to investigate potential mechanism of antifungal activity of Aspidin BB against Trichophyton rubrum which is the most common pathogens responsible for chronic dermatophytosis. Methods The minimum inhibitory concentration （MIC） ofAspidin BB against strains was determined by broth microdilution. The effects of Aspidin BB on ergosterol biosynthesis were investigated by content determination based on UPLC method. Besides, the effects of drugs on squalene epoxidase （SE） in T. rubrum cell membrane were analyzed. Results MIC value of Aspidin BB against T. rubrum was 25.0 IJg/mL. Aspidin BB reduced ergosterol content significantly, but no notable effect on squalene epoxidase activity. Conclusion The results suggested that Aspidin BB inhibited ergosterol biosynthesis. However, it was not squalene epoxidase but other components may sever as possible targets in ergosterol biosynthesis pathway.