Human marrow-derived mesenchymal progenitor cells

A number of adult mesenchymal tissues contain subpopulations of undifferentiated cells, which retain the capacity to differentiate along multiple lineages. These mesenchymal progenitor cells may be cultured in an undifferentiated state and, when given the appropriate signals, differentiate into an expanding list of several mesenchymal and a few ectodermal derived tissues. The maintenance and propagation of the multipotential nature of these progenitor cell populations are crucially dependent on the isolation protocol, the culture expansion conditions, particularly the properties of the fetal bovine serum supplement in the culture medium. This article describes a method for selection of the appropriate serum lot, and introduces a simplified isolation technique to optimize the yield of progenitor cells that maintain the capability of undergoing multilineage differentiation in response to appropriate cues. Cell populations isolated and culture expanded in this manner, by virtue of their multiple differentiation potential, should serve as ideal candidate cells for tissue engineering applications for the repair and regeneration of tissue damaged by disease and or trauma.     

A tissue culture system for different germplasms of indica rice

Agrobacterium-mediated transformation of indica rice has been manipulated in only a limited number of cultivars because the majority of indica varieties are recalcitrant to in vitro response. Establishment of a highly efficient and widely used tissue culture system for indica rice will accelerate the application of transformation technology in breeding programs and the study of the functions of indica-specific genes. By manipulating plant growth regulators, organic components and salts within the culture media, we established two media for callus induction and subculture, respectively, in tissue culture of indica rice. The modified media could guarantee the production and proliferation of a great number of embryogenic calli with high regeneration capacity from mature seeds representing different indica rice germplasms. The calli obtained from this system should be ideal material for Agrobacterium-mediated transformation. The results suggest that this optimized tissue culture system will be widely applicable for the tissue culture of indica varieties. Electronic Supplementary Material Supplementary material is available for this article at The first two authors contributed equally to this work.     

Femaleness in breeding glasshouse cucumbers

In growing parthenocarpic cucumber varieties the occurrence of bullnecks due to pollination by bees is a problem. To prevent the formation of these bullnecked cucumbers the possibilities of breeding female-flowered varieties were explored. Use was made of material derived from the gynoecious line MSU 713-5. Femaleness is caused by the gene Acr, which accelerates the production of female flowers. Within the type which, genetically, must be regarded as female, a variation occurs from total absence of male flowers to rather numerous axils with male flowers, mainly on the lower part of the stem. On the one hand this variation is also genetically controlled, and we may speak of “weakly” female and “strongly” female. On the other, environmental factors play an important part. The formation of male flowers in preponderantly female-flowered material is promoted by a long day, high night temperature and particularly, at least with our material, low light intensity; furthermore by a low pH of the soil and rich dressings of nitrogen. In order to be able to distinguish during selection between the weakly and strongly female plants, the environmental conditions should be favourable for the formation of male flowers. The maintenance of female plants is possible, because the formation of male flowers can be induced by spraying with gibberellin, after which selfing can be practised. Old plants respond less readily to gibberellin than young plants. Also, the response from strongly female plants is less pronounced than that from weakly female ones, which offers another possibility of selection. The extent to which male flowers may occur when growing female varieties depends on the cultivation method used. With the conventional method fruiting is forced to begin mainly on the laterals and any male flowers, if confined to the main stem, could be removed early. However, in view of fluctuations caused by the environment a rather pronounced female character will be desirable. Other cultivation methods are conceivable, e.g. short-term cultivation of larger numbers of plants per area unit, allowing the plants to come into bearing rapidly. The total absence of male flowers is then indispensable. With the aid of the femaleness it is also possible to simplify the production of hybrid seed, as hand pollination can be replaced by bee pollination. The combination gynoecious × monoecious, which in itself is the most favourable for this purpose, has the drawback that the resulting hybrid is usually insufficiently female. Therefore, use will generally have to be made of the combination gynoecious × gynoecious, spraying the latter parent with gibberellin.     

In vitro regeneration of adult Pinus sylvestris L. trees

The propagation of adult conifer trees by tissue culture has been studied for the last twenty years, but problems related to the juvenile to adult phase change of trees have limited the practical applications of these tissue culture procedures. This paper describes a micropropagation protocol for the in vitro propagation of mature Scots pine trees. In this study, dormant shoot buds, which had not started to elongate, were collected from twenty-one adult Pinus sylvestris trees (> 15 years old) during the winter. The sampled buds were cut transversely into slices of 0.5 to 1 cm in thickness and were cultured on three types of culture media (DCR, WP and LPm) supplemented with four cytokinins (BA, mT, Tdz and Z), at two different concentrations (25 and 50 µM), except for Tdz, whose concentrations were diluted to 5 µM and 2.5 µM. The evaluated culture media did not show significant differences in the bud organogenesis capacity. In fact, the highest organogenic response was obtained with buds cultured on DCR and WP media and by explants cultured on medium supplemented with 25 µM meta-topolin. This protocol is a successful and efficient biotechnological approach to the micropropagation of adult P. sylvestris trees.     

西双版纳鸡嗉果榕小蜂繁殖和传粉行为

鸡嗉果榕 Ficus semicordata Buch.-Ham.ex J. E. Sm.是西双版纳地区常见的榕属植物,它是热带雨林生态系统中的一类先锋树种,当热带雨林被破坏后,它最先在林缘、沟谷和路边迅速生长起来,是热带和亚热带地区森林生态系统恢复初期一类重要物种。在西双版纳通过不同样地定树、定期生态学观察和室内剖查不同生长时期的鸡嗉果榕隐头果的方法,对榕小蜂繁殖和传粉行为进行了研究,结果表明,鸡嗉果榕雌雄异株,在西双版纳一年结2～3次隐头果,雌株隐头果内小花由榕小蜂传粉后产生种子。雄株则产生雄花和中性小花,中性小花专门供给传粉小蜂产卵繁殖后代。鸡嗉果榕小蜂Ceratosolen gravelyi Grandi是鸡嗉果榕唯一的传粉昆虫。传粉小蜂的雄蜂比雌蜂早羽化30～90 min,一部分雄虫羽化后,在虫瘿上爬动寻找雌蜂寄生的瘿花,一找到雌蜂寄生的瘿花,就咬破虫瘿的一个小口,把生殖器伸进瘿花与雌蜂交配,一部分雄蜂则在果肉上咬出蜂口。雌蜂交配后,顶大交配孔出蜂爬到雄花区采集花粉,然后,飞出寻找鸡嗉果榕雌花期的嫩隐头果传粉和繁殖后代。到鸡嗉果榕雌株传粉的小蜂能飞翔300～500 m,进果腔传粉行为长达5～27 h,传完粉3～5 h在果腔内死亡。到雄株上繁殖的小蜂一般飞翔在20～100 m左右近距离寻找嫩隐头果,进果腔产卵,每只小蜂在无干扰的情况下可产400多粒卵。除传粉榕小蜂外,在鸡嗉果榕雄株隐头果上还有4种植食、造瘿和复寄生等非传粉小蜂,它们对传粉小蜂的种群繁衍影响很大,常使传粉小蜂的种群数量降低25～70%。每个隐头果内进传粉小蜂量多少对鸡嗉果榕和榕小蜂繁殖有关,最佳进蜂量为3只,高或低于最佳进蜂量对鸡嗉果榕树和它的传粉小蜂繁殖均不利。     

Heat Production in the Voodoo Lily (Sauromatum guttatum) as Monitored by Infrared Thermography

The pattern of surface temperatures of the inflorescence of Sauromatum guttatum was investigated by using an infrared camera. The male flowers are weakly thermogenic on the first day of inflorescence opening (D-day) as well as on the next day (D + 1), reaching 0.5 to 1°C above ambient temperature. The appendix (the upper sterile part of the inflorescence) is highly thermogenic on D-day, reaching 32°C, and is faintly thermogenic on D + 1, reaching 1°C above ambient temperature. The lower part of the spadix, close to the female flowers, is also thermogenic on D-day and D + 1, reaching a temperature similar to that of the appendix only on D + 1. Salicylic acid does not induce heat production in the lower part of the spadix, as it does in the appendix. Respiration of tissue slices obtained from the appendix shows that the capacity for cyanide-insensitive respiration is present in young and mature appendices. This alternative respiratory pathway is not, however, utilized in young appendix tissue, but is engaged during the maturation of that tissue.     

四川攀西地区南亚热带观赏花卉引试种初报

本文报道四川攀西地区引进的53科143个观赏花卉品种的引种试种情况。结果表明,所引进的品种在攀西地区均表现为适应性较强,可望成为今后该地区发展观赏花卉的主导品种。     

Development of male and female flower in Asparagus officinalis. Search for point of transition from hermaphroditic to unisexual developmental pathway

Asparagus officinalis is a dioecious plant. The flowers start to develop as hermaphrodites and later become unisexual. In female flowers the stamens degenerate, while in male flowers the ovary stops growing without degenerating. We have examined young asparagus flowers using SEM and optical microscopy in order to determine the exact moment of transition from hermaphroditic to unisexual development. We defined 13 stages of development, starting from flower primordia up to completely mature flowers and labelled them with numbers from -6 to 7. The first five stages are fully hermaphroditic: a difference between sexes becomes visible at stage — 1 when the style begins to develop in female flowers. Degeneration of stamens in female flowers starts somewhat later. At the stage of transition, some differences between sexes also appear in the bidimensional polypeptide pattern of flowers. RNase activity shows a distinct peak at this stage (in female flowers only), probably related to stamen degeneration.     

香蕉小茎尖培养和快速繁殖

本文报道14个香蕉品种或品系进行小茎尖离体培养繁殖无病苗。小茎尖培养在改良MS培养基中,附加BA2.0—5.0mg/l,试验结果显示,BA明显促进芽的形成和增殖,随着BA浓度的增高,形成的芽苗数也随着增多。各品种均能诱导丛生芽,但品种间的繁殖率有很大差异。低浓度的Kt或BA有利于诱导生根。培养的试管苗经检验为无病苗。     

黄瓜雄花形成过程中心皮的发育

黄瓜(Cucumis sativus L.)为重要的经济作物,雌雄同株异花,是研究植物性别分化的经典材料。人们对黄瓜性别分化进行了广泛的研究。Astmon和Galun、任吉君和王艳对黄瓜性别分化的形态特征和器官发生进行了初步研究,表明黄瓜单性花分化和发育过程中经历了无性期、两性期和单性期,最终只有一种性别的性器官原基发育成有功能的性器官,从而形成单性花,而对单性花中未形成有功能器官的相反性别原基的研究报道甚少。我们对雄花发育过程进行了连续的形态学分析,并对不同时期雄花中的心皮进行了细胞计数和同工酶电泳分析,以期从性器官发育的角度探讨黄瓜性别表现的机理。     

黄瓜雄花形成过程中心皮的发育

黄瓜(Cucumis sativus L)为重要的经济作物,雌雄同株异花,是研究植物性别分化的经典材料。人们对黄瓜性别分化进行了广泛的研究。Astmon和Galun,任吉君和王艳对黄瓜性别分化的形态特征和器官发生进行了初步研究,表明黄瓜单性花分化和发育过程中经历了无性期、两性期和单性期,最     

薜荔和爱玉及其传粉昆虫繁殖特性

薜荔(Ficus pumila L．var．pumila)隶属桑科榕属,爱玉(F．pumila L．var．awkeotsanmg Corner)为其变种,它们的花是单性的,雌雄异株。雌花序中着生雌花,雄花序中有瘿花和雄花,每个花序中花的数量极多,达4000～6000朵。薜荔榕小蜂是唯一能进入薜荔和爱玉的隐头花序中产卵或传粉的共生昆虫,自然状态下雌花的结实率分别为82％、83．52％;瘿花的成虫瘿率分别为58．71％、51．32％,因此可形成大量的果实和虫瘿。物候观察表明薜荔和爱玉花期不遇,它们花序中的榕小蜂种群已经生殖隔离。人为的放蜂实验表明,生活于爱玉花序中的榕小蜂,已无法在薜荔花序中繁殖,生殖隔离进一步得到证实;实验同时表明爱玉的花粉亦不能使薜荔雌花结实,宿主两变种间生理上已不亲和。本文从共生双方协同进化的角度出发,探讨了榕树2变种间与传粉昆虫繁殖特性的差异,以及变种产生的主要原因。     

Somatic embryogenesis in Pinus halepensis Mill.: an important ecological species from the Mediterranean forest

Pinus halepensis Mill. is a common forest species in the Mediterranean area and it is important for environmental conservation. This study established a method of regenerating Pinus halepensis Mill. through somatic embryogenesis. The effect of culture medium (mineral salts, nitrogen source and plant growth regulators), collection date and seed family on embryogenic tissue initiation and proliferation in Pinus halepensis was analysed during the first steps of embryogenesis process. This study showed a marked effect of the culture medium tested as well as some significant differences among collection dates. Furthermore, the embryogenic tissue initiation was affected by the amino acid mixture in the culture medium and the proliferation stage was significantly affected by the combination of plant growth regulators. At the end of the maturation phase the presence of activated charcoal was also evaluated. Finally, maturation of embryogenic tissue was affected by the nitrogen source in the culture medium and these results were different for high and low mature embryo producing cell lines. To the best of our knowledge, this is the first report on Aleppo pine somatic embryogenesis describing a simple and efficient procedure for large-scale somatic embryo production.     

Improvement of plastic-based disposable bioreactors for plant science needs

The present article describes two new applications of plastic-based cell culture systems in the plant biotechnology domain. Different types of bioreactors are used at Nestlé R&D Center-Tours for large scale culture of plants cells to produce metabolites or recombinant proteins and for mass propagation of selected plant varieties by somatic embryogenesis. Particularly, recent studies are directed to cut down the production costs of these two processes by developing disposable cell culture systems. For large scale culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to 100 l working volumes, validated with several plant species (“Wave and Undertow” and “Slug Bubble” bioreactors). Vegetative propagation of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has been recently set up for the industrial propagation of Coffea canephora (Robusta coffee). The current production capacity is 2.5–3.0 million embryos per year. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in 10-l glass bioreactors. An improved process has been developed using a 10-l disposable bioreactor consisting in a bag containing a rigid plastic box (“Box-in-Bag” bioreactor), insuring, amongst other advantages, a higher light transmittance to the biomass due to its horizontal design.     

Reproductive developmental complexity in the African oil palm (Elaeis guineensis, Arecaceae)

Species of the palm family (Arecaceae) are remarkably diverse in their inflorescence and floral morphologies, which make them a particularly interesting group for studies of reproductive development and its evolution. Using light and scanning electron microscopy, we describe inflorescence and flower development in the African oil palm Elaeis guineensis from the initiation of the inflorescence meristem to flower maturity. In mature palms, the inflorescence develops over 2-3 years and is characterized by individual stages within which differentiation may be either relatively slow, as in the case of early inflorescence meristem development, or rapid, as in the case of flower organogenesis. The female inflorescence bears floral triads composed of single pistillate flowers flanked by two abortive staminate flowers, whereas the male inflorescence contains single functional staminate flowers. This suggests a possible evolutionary movement from an ancestral hermaphrodite inflorescence form containing fully functional floral triads to the situation of temporal dioecy observed at present. Wild type flowers are compared to those bearing an epigenetic homeotic abnormality, known as mantled, involving an alteration of the identity of the organs in the fertile and sterile androecium.     

Staminodes evolution and in vitro development innovation in date palm (Phoenix dactylifera L.)

The in vitro cultivation of date palm staminodes (vestigial stamens) at different stages of female floral ontogenesis confirms the persistence at an immature state of such organs at all the floral differentiation stages. This is evidenced even in fully mature female flowers. Our study revealed the advanced developmental patterns of these rudimentary structures, which bear diverse morphogenetic potentialities. In vitro cultivation of staminodes provides new opportunities for in vitro regeneration of date palm. Such developmental processes were found to be modulated by the stage of floral differentiation, which closely reflected the level of staminode maturity. Development was also impacted by the composition and concentration in plant growth regulators (NAA, BAP and 2,4-D) of the culture media. The large morphogenetic plasticity of the staminodes disposed them to evolutionary variations of the date palm reproduction system. The practical benefits (micropropagation) and the fundamental interests (evolutionary process) of our investigation are discussed.     

Flower choice by honey bees (Apis mellifera L.): sex-phase of flowers and preferences among nectar and pollen foragers

Bees foraging for nectar should choose different inflorescences from those foraging for both pollen and nectar, if inflorescences consist of differing proportions of male and female flowers, particularly if the sex phases of the flowers differ in nectar content as well as the occurrence of pollen. This study tested this prediction using worker honey bees (Apis mellifera L.) foraging on inflorescences of Lavandula stoechas. Female flowers contained about twice the volume of nectar of male flowers. As one would predict, bees foraging for nectar only chose inflorescences with disproportionately more female flowers: time spent on the inflorescence was correlated with the number of female flowers, but not with the number of male flowers. Inflorescence size was inversely correlated with the number of female flowers, and could be used as a morphological cue by these bees. Also as predicted, workers foraging for both pollen and nectar chose inflorescences with relatively greater numbers of both male and female flowers: time spent on these inflorescences was correlated with the number of male flowers, but not with the number of females flowers. A morphological cue inversely associated with such inflorescences is the size of the bract display. Choice of flowers within inflorescences was also influenced predictably, but preferences appeared to be based upon corolla size rather than directly on sex phase.     

Biotechnological approaches to breeding and cultivation of ornamental crop plants

Recent advances in plant biotechnology hold great potential for the ornamental horticulture industry. In addition to conventional methods, breeders can now introduce genetic variation into ornamentals by the application of recombinant DNA technology. This technology is particularly useful for effecting changes in phenotypic expression encoded by single genes such as corolla and foliage color and texture, stem length, scent, temporal regulation of flowering, vase life of cut flowers and resistance to stressful environments. In part, the commercial success of this technology will depend on developing reliable methods of transformation of ornamentals and on the stability of the introduced or altered genes. In addition, new and improved strategies of in vitro culture have been commercially implemented for the propagation and breeding of a wide variety of ornamental crops and will undoubtedly play a major role in the screening and propagation of chimeric plants developed by recombinant DNA technology.     

Bacterial endophyte communities of two wheatgrass varieties following propagation in different growing media

Bacterial endophyte communities of two wheatgrass varieties currently being used in the revegetation of military training ranges were studied. Culturable and direct 16S rDNA PCR amplification techniques were used to describe bacterial communities present in Siberian and slender wheatgrass seeds, leaf tissues, and root tissues following propagation in either sand or a peat-based growing mix. Our hypothesis was that the resulting plant endophytic communities would be distinct, showing not only the presence of endophytes originating from the seed but also the characteristics of growth in the two different growing media. Both culture and culture-independent assays showed the likely translocation of Actinobacteria, Firmicutes, and Gammaproteobacteria from seed to mature plant tissues as well as subsequent colonization by exogenous organisms. Statistical analysis of 16S terminal restriction fragment profiles identified growing media as having a greater significant effect on the formation of the endpoint endophytic communities than either plant tissue or wheatgrass variety. In silico digests of the ribosomal database produced putative identifications indicating an increase in overall species diversity and increased relative abundances of Firmicutes and Cyanobacteria following propagation in sand and Betaproteobacteria following propagation in the peat-based growing mix. Results indicated a substantial translocation of endophytes from seed to mature plant tissues for both growing media and that growing medium was a dominant determinant of the final taxonomy of the endpoint plant endophytic communities.