In-vitro cloning of Dittrichia viscosa for screening nutritional ecotypes

Difficulties were encountered for in-vivo propagation of plants used for screening populations during evolutionary studies of Dittrichia viscosa W. Greuter, an invading ruderal species of the Asteraceae. Conditions suitable for in-vitro propagation of D. viscosa were first investigated. Plants were in-vitro cloned from nodal segments, and the best medium for mass production was a modified Murashige and Skoog medium. Up to 5 nodal microsegments could be produced per segment, and by repeated passages over 4 months, more than 10,000 microsegments were obtained. The segments were rooted in auxin-free medium and the plantlets, resembling juvenile plants, were grown in sand culture. Ecotypes from two contrasting mineral habitats and differing in their ability to select major cations (K, Ca and Mg), i.e. nutritional ecotypes, were cloned in vitro and in vivo and compared in common hydroponic conditions. Differences observed in cation accumulation were similar, irrespective of whether plants were derived from in-vitro or in-vivo clones. In-vitro culture did not alter the nutritional responses as observed with in-vivo mature plants.     

滇西香茅挥发油的化学成分

滇西香茅(Cymbopogon khasiamus(Hack.)Stapf ex Bor)为禾本科植物,分布于印度及缅甸,该植物过去在中国无分布记载,作者在云南首次发现。其挥发油为主要有效成分,当地与芸香草(Cymbopogon distans(Steud)Wats.)混用。为合理开发和利用该种植物,对挥发油的化学成分进行了分析。     

安徽植物增补及地理新分布Ⅱ

本文第二次增补《安徽植物志》未记入的植物２２种５变种。其中２０种３变种为安徽地理新分布,３属（白屈菜属、离子芥属和石莲属）为安徽地理新分布属。本文所引用的植物标本,全部收藏于安微大学资源植物标本室。     

渐危植物珊瑚菜试管植株的培养

渐危植物珊瑚菜试管植株的培养惠红１蒋宁２刘启新１（１江苏省中国科学院植物研究所,南京２１００１４,２美国佐治亚大学园艺系,美国ＧＡ３０６０２）Ｏｎｔｈｅｃｕｌｔｕｒｅｏｆｔｅｓｔ┐ｔｕｂｅｐｌａｎｔｌｅｔｆｒｏｍｒｈｉｚｏｍｅｓｏｆｔｈｒｅａｔｅｎ...     

中国石蒜属植物花粉形态的研究

利用光学显微镜和扫描电镜对我国石蒜属ＬｙｃｏｒｉｓＨｅｒｂ．１１种植物花粉形态进行系统地研究,并对其中６种具有代表性植物花粉进行了透射电镜观察。该属植物花粉舟形或肾形;萌发孔为远极单槽;在光学显微镜和扫描电镜下观察,外壁具网状纹饰;在透射电镜下观察,外壁包括外壁－１和外壁－２两层,外壁－１是由半覆盖层、柱状层和基层组成,外壁－２很薄。根据花粉形态及其他器官特征,对本属植物分类地位也进行了一些讨论。     

The efficiency of transfer of plants cultivated in vitro to ex vitro conditions as affected by sugar supply

The greatest growth of wheat and rape plants in vitro was reached on media with 5 or 9 % sucrose, respectively. The highest efficiency for transfer of these plants to ex vitro conditions was found at the same sucrose concentrations. The content of endogenous non-structural saccharides (glucose, fructose, sucrose, starch and fructans) increased with increasing sucrose concentration in the medium up to 10 %. This revised version was published online in July 2006 with corrections to the Cover Date.     

Expansion of CD34+ cells from human umbilical cord blood by FL and/or TPO gene transfected human marrow stromal cell lines

To elucidate the effect of gene transfected marrow stromal cell on expansion of human cord blood CD34+ cells, a culture system was established in which FL and TPO genes were transfected into human stromal cell line HFCL. To establish gene transfected stromal cells co-culture system, cord blood CD34+ cells were purified by using a magnetic beads sorting system. The number of all cells and the number of CD34+ cells and CFC (CFU-GM and BFU-E) were counted in different culture systems. The results showed that in all 8 culture systems, SCF+IL-3+HFT manifested the most potent combination, with the number of total nucleated cells increasing by (893.3±52.1)-fold, total progenitor cells (CFC) by (74.5±5.2)-fold and CD34+ cells by 15.7-fold.Maximal expansions of CFC and CD34+ cells were observed at the end of the second week of culture. Within 14 days of culture, (78.1 ± 5.5)-fold and (57.0 ± 19.7)-fold increases in CFU-GM and BFU-E were obtained. Moreover, generation of LTC-IC from amplified CD34+ cells within 28 days was found only in two combinations, I.e. SCF+IL-3+FL+TPO and SCF+IL-3+HFT, and there was no significant difference between these two groups statistically. These results suggest that human umbilical cord blood CD34+ cells can be extensively expanded ex vivo by using gene transfected stromal cells along with cytokines.     

Photosynthetic acclimation to low temperature by western red cedar seedlings

Imposition of low, but above freezing, temperatures resulted in a gradual increase in the cold hardiness of western red cedar seedlings. This was associated with a decrease in the maximum rates of photosynthetic CO₂ fixation and O₂ evolution, and changes in chlorophyll a fluorescence transients which indicated that photoinhibition had occurred. Maximum photosynthetic rates declined approximately 40% during cold hardening. The leaves changed colour from green to red-brown during the hardening process. The colour change was due to the synthesis of large amounts of the carotenoid rhodoxanthin. Lutein levels doubled, while chlorophyll declined slightly. Dehardening resulted in the rapid recovery of photosynthesis to control levels, the rapid disappearance of rhodoxanthin, and the return of lutein levels to control. It is suggested that rhodoxanthin accumulation at low temperature functions to decrease the light intensity reaching the photosynthetic apparatus. The combination of photoinhibition and rhodoxanthin synthesis probably serves to protect the photosynthetic capacity of the seedlings at low temperature.