The role of inner staminodes in the floral display of some relicMagnoliales

The inner staminodes (between stamens and carpels) in some relicMagnoliales (Austrobaileyaceae, Degeneriaceae, Eupomatiaceae, andHimantandraceae) are not just reduced stamens; they are very elaborate organs. InEupomatiaceae, Himantandraceae, and probablyDegeneriaceae they have their own secretory structures which do not occur on the stamens. These play an important role in floral biology. They contribute to the floral coloration pattern; they effect herkogamy by their position and by movements; they provide shelter and food tissue and food secretions (?) for pollinating beetles; they secrete odouriferous oils, mucilage (probably for pollen adherence) and water or nectar (?). For theHimantandraceae a new secretory region on the base of the inner staminode is described. These complicated inner staminodes are extreme specializations of primitive floral types. They have no counterparts in more advanced subclasses of the angiosperms.     

Interaction between oil-collecting bees and seven species of Plantaginaceae

Oil-bee/oil-flower mutualism evolved through multiple gains and losses of the ability to produce floral oil in plants and to collect it in bees. Around 2000 plant species are known to produce floral oils that are collected by roughly 450 bee species, which use them for the construction of nests and for the larval food. The Plantaginaceae contain several Neotropical species that produce floral oils, the main reward offered by these plants. In the genera Angelonia, Basistemon, Monopera and Monttea, mainly associated with Centris bees, the floral oil is produced in trichomes that are located in the inner corolla. The pollinators of a few species in this neotropical clade of Plantaginaceae are known, and the role of flower morphology as well as the requirements from pollinators and the role of other groups of bees in the pollination of these flowers remains unclear. In this paper we provide a list of the flower visitors of seven Plantaginaceae species (six Angelonia species and Basistemon silvaticus) analyzing their behavior to highlight the legitimate pollinators and illustrating little known aspects of flower morphology and oil-collecting apparatuses of the bees. Two general morphological patterns were observed in the Angelonia flowers: deep corolla tube with short lobes, and short corolla tube with long lobes. Corolla tubes of different length result in pollen adherence to different parts of the insect body. The six Angelonia species and B. silvaticus flowers were visited by 25 oil-collecting bee species (10 Centris, 11 Tapinotaspidini and 4 Tetrapedia species), the majority acting as legitimate visitors. The flowers were also visited by illegitimate bee pollinators, which collected pollen but do not transfer it to the female organ. Specialized collectors of Plantaginaceae floral oils present modifications on the first pair of legs, mainly in the basitarsi but also extended to the tarsomeres. The new records of Tapinotaspidini and Centridini species acting as specialized pollinators of Plantaginaceae suggest that there is a geographic variation in the pollinators of the same plant species, and that the evolutionary scenario of the historical relationships between oil-collecting bees and floral oil producing plants is more complex than previously considered.     

Floral biological observations onHeliamphora tatei (Sarraceniaceae) and other plants from Cerro de la Neblina in Venezuela

During 20 days in 1985, floral biological observations were made at 1 850–2 100m elevation on Cerro de la Neblina in Venezuela.Heliamphora tatei var.neblinae (Sarraceniaceae) is nectarless and has poricidal anthers.Heliamphora tatei, Graffenrieda fruticosa, G. polymera, G. reticulata, Tocca pachystachya, T. tepuiensis (Melastomataceae),Saxofridericia compressa, andStegolepsis neblinensis (Rapateaceae), are buzz-pollinated by ten species ofBombus, Eulaema, Melipona, Centris, Xylocopa, Dialictus, andNeocorynura. Additional observations of floral visits on tepui species ofGentianaceae, Loranthaceae, Malpighiaceae, Ericaceae, Orchidaceae, andAsteraceae are reported. Visitors include the hummingbirdCampylopterus duidae, the flower-piercerDiglossa duidae, the nectarivorous batAnoura geoffroyi, and various species ofCentris andBombus bees. Scent baits for euglossine bees attracted very few bees.Apis mellifera adansonii-scutellata, the africanized honey bee, was caught at 1 850m elevation.     

Phylogeny of the ectomycorrhizal mushroom genus Alnicola (Basidiomycota, Cortinariaceae) based on rDNA sequences with special emphasis on host specificity and morphological characters

Alnicola (=Naucoria, pro parte) is a mushroom genus of strictly temperate, obligately ectomycorrhizal species, traditionally included in the family Cortinariaceae. Most Alnicola spp. are primarily host specific on Alnus, although a few are mycobionts of Salix or other hosts. The different species of Alnicola exhibit unique morphological (cystidia, pileipellis) and cytological (dikaryotic or monokaryotic hyphae) characters. This makes the genus Alnicola of particular interest for studying the evolution of host specificity and morphological characters in ectomycorrhizal basidiomycetes. We used a combination of classical morphological and phylogenetic methods (rDNA ITS and LSU sequences) to address the following questions: (i) Is Alnicola monophyletic? And (ii) Are characters like host specificity or microscopical structures synapomorphic for certain clades? The study included nearly all currently known European Alnicola sp. Our results demonstrated that, on one hand, the genus Alnicola is polyphyletic, with sistergroup relationships to Hebeloma, Anamika or the clades /Hymenogaster I and /Hymenogaster II. On the other hand, Alnicola splits into three well-supported clades corresponding to the sections Alnicola, Submelinoides, and Salicicolae. The strict host-specificity to Alnus is a derived character and has occurred at least twice. The following morphological characters are synapomorphic for defined clades: the spindle-shaped hymenial cystidia for sect. Alnicola, the hymeniform pileipellis for sect. Submelinoides, and monocaryotic/clampless hyphae for sect. Salicicolae and its sistergroup /Hymenogaster II. As a taxonomical consequence, polyphyly of Alnicola implies that the sects. Submelinoides and Salicicolae need to be segregated from Alnicola.     

Biostatistical studies on western EuropeanDactylorhiza (Orchidaceae)—theD. maculata group

Multivariate analysis tools are exploited on a data set composed of quantitative characteristics collected on 35 populations of plants of theDactylorhiza maculata (L.)Soó group from Western-Europe. These samples lead to four well-defined clusters; this, together with qualitative, cytological and ecological arguments, allows for the recognition of four specific entities:D. maculata s.str.,D. fuchsii (Druce)Soó,D. saccifera (Brongn.)Soó andD. caramulensis (Vermeulen)Tyteca. It is concluded that the floral characters play an essential role in the taxonomical distinction. It also appears that the set of characters measured, as well as the methods exploited, are especially well-suited and valuable tools for the morphological study of the genusDactylorhiza.     

The production of floral oils byMonttea (Scrophulariaceae) and the function of tarsal pads inCentris bees

Plant species that secrete oil as their primary floral reward are rare and sporadically found in the angiosperms. We report here thatMonttea, a genus previously unsuspected of being an oil-plant, produces lipids from trichome elaiophores on the inside of the lower (anterior) lip. The discovery of the production of oils by species of this S. American genus explains the occurrence of unusual dual-function collecting structures in ArgentineCentris (Hymenoptera: Anthophoridae) and explains the presence of oil-collecting bees in regions where oil-secreting flowers were previously thought to be absent. The behavior of these centridine pollinators onMonttea flowers parallels that of oil-collecting bees onDiascia (Scrophulariaceae) in S. Africa.     

Organogenesis of vegetative shoots from in vitro cultured flower buds of Mammillaria albicoma (Cactaceae)

We tested the organogenetic capacity of floral buds of Mammillaria albicoma Böed. (Cactaceae). Buds were incubated on solid MS medium supplemented with 0.1 mg l^?1 α-naphthaleneacetic acid (NAA) and 5.0 mg l^?1 6-benzylaminopurine (BA). Callus growth was observed from the cut explant base and from within the perianth. These calli during subsequent subcultures to the same medium gave rise to adventitious shoots. Shoots formed also directly from the perianth, as confirmed by observations in the light microscope and scanning electron microscope (SEM). On transfer to a fresh medium, the shoots produced proliferating cultures. This is the first report of regeneration of cactus shoots from floral explants.     

Comparative floral and vegetative differentiation between two European Aquilegia taxa along a narrow contact zone

As a first step in determining the identity and relative importance of the evolutionary forces promoting the speciation process in two closely related European taxa of Aquilegia, we investigated the levels of morphological variation in floral and vegetative characters over the narrow region where their ranges enter into contact, and evaluate the relative importance of both types of traits in their differentiation. A total of 12 floral and ten vegetative characters were measured on 375 plants belonging to seven A. vulgaris populations and six A. pyrenaica subsp. cazorlensis populations located in southeastern Spain. Floral and vegetative morphological differentiation occur between taxa and among populations within taxa, but only vegetative characters (particularly plant height and leaf petiolule length) contribute significantly to the discrimination between taxa. Differentiation among populations within taxa is mostly explained by variation in floral traits. Consequently, morphological divergence between the two taxa cannot be interpreted as an extension of among-population differences occurring within taxa. Multivariate vegetative, but not floral, similarity between populations could be predicted from geographical distance. Moreover, the key role of certain vegetative traits in the differentiation of A. vulgaris and A. p. cazorlensis could possibly be attributable to the contrasting habitat requirements and stress tolerance strategies of the two taxa. These preliminary findings seem to disagree with the currently established view of the radiation process in the genus Aquilegia in North America, where the differentiation of floral traits seems to have played a more important role.     

Notes on the floral morphology in Vivianiaceae (Geraniales)

The functional floral morphology of the three genera of Vivianiaceae (= Ledocarpaceae, Geraniales), Rhynchotheca, Viviania and Balbisia, is compared. Likely pollination mechanisms are inferred from morphology and field observations. The flowers of Viviania are nectariferous and apparently zoophilous with nectar as the (primary) pollinator reward. Balbisia has pollen flowers without nectaries, its showy corolla indicates that it is also zoophilous with pollen as sole pollinator reward; bees were observed as flower visitors. One taxon (B. gracilis) may be anemophilous. Rhynchotheca has flowers without petals, with large, pendulous anthers and lacks nectaries. It shows synchronous mass flowering in its natural populations and is evidently anemophilous. A comparison with other Geraniales shows that nectar flowers with small anthers are likely the ancestral condition in Vivianiaceae. This suggests that the pollen flowers with larger anthers of Balbisia and Rhynchotheca may represent an apomorphic condition. The documentation of pollen flowers and anemophily in Vivianiaceae expands the range of known floral and pollination syndromes in Geraniales.     

贵州特有药用植物毕节小檗的形态变异

为探讨贵州特有药用植物毕节小檗(Berberis guizhouensis)形态多样性的变异式样及其适应机制,对其野外居群营养器官和花部形态进行研究。对毕节小檗一直空缺的花部性状进行了描述。结果表明,毕节小檗的性状在同一居群或同一性状在不同居群中都存在较丰富的变异,变异系数为0.03~0.57。从总体来看,营养器官性状的变异程度要高于花部性状。单因素方差分析表明居群间部分花部性状存在显著差异(P0.05)。聚类分析表明小白岩居群形成1个独立的分支,这种分化很可能是环境压力选择的结果。主成分分析表明花部性状与营养性状在维持形态结构的稳定性具有协调一致的生态适应。     

<Emphasis Type="Italic">SQUA</Emphasis>-like genes in the orchid <Emphasis Type="Italic">Phalaenopsis</Emphasis> are expressed in both vegetative and reproductive tissues

The SQUA family (AP1/FUL family) of MADS-box genes plays an important role in the transition from the vegetative to the reproductive development of angiosperms, and its origin might be concurrent with fixation of floral structure in angiosperms. Here, we isolated two Phalaenopsis MADS-box genes designated ORAP11 and ORAP13, both of which belong to the monocot FUL-like clade of the SQUA family. RT-PCR showed that both genes are strongly expressed in the floral bud, and also detected in the vegetative organs. During later stages, ORAP11 was only detected in the column, but ORAP13 signal was absent from all of the floral organs. In-situ hybridization experiments detected both genes in the tips and margins of developing petals and lips, the developing column, and ovule. Over-expression of both genes in tobacco induced early flowering and changed plant architecture. Our results suggest that in Phalaenopsis, both genes might share partly redundant activities and play important roles in the process of floral transition and morphological architecture. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Gynoecium development inRubiaceae-Vanguerieae,with particular reference to the “stylar head”-complex and secondary pollen presentation

Gynoecium development in taxa of the tribeVanguerieae (Rubiaceae, subfam.Antirheoideae) was studied, using primarily a 2- and a 5-carpellate genus (Keetia andVangueria) as examples. All investigated taxa, characterized by ovaries with a solitary, ± apically inserted, pendulous anatropous ovule per locule/carpel, showed a very similar gynoecium development. Comparisons with other uniovulateRubiaceae (taxa of subfam.Rubioideae) revealed that notwithstanding the place of insertion and orientation of the solitary ovules (apically vs. basally inserted, pendulous vs. erect, anatropous ovules) the gynoecium development follows the same pattern; differing ovule insertion and orientation can easily be explained by the principle of variable proportions. — Since secondary pollen presentation is characteristic for the tribe, particular attention was paid to the development of the conspicuous “stylar head”-complex, defined here as structural unit comprised of pollen presenting organ, “receptaculum pollinis”, plus stigmatic (i.e., receptive) surfaces. It was found that their morphological differentiation, following the same pattern in all investigated taxa, starts at very early stages of floral development. They already had their final shape at a stage when the ovule development in the ovary had just barely started. The fully developed, actual “receptaculum pollinis” is made up of enormously enlarged, ± cylindrical epidermis cells which have peculiar ring-like thickenings in vicinity of and parallel to the outer tangential walls (a “mechanical barrier” preventing pollen tubes from entering?) and a much smaller-celled subepidermal tissue. With regard to shape, size, and exposure of the stigmatic surfaces, the investigated taxa exhibited certain morphological differences. These were found to be correlated with differences in androecium structure (and, ultimately, pollen presentation).     

Floral scent chemistry and pollination ecology in phytelephantoid palms (Arecaceae)

The subfamilyPhytelephantoideae comprises three genera (Ammandra, Aphandra, andPhytelephas) and seven species of dioecious palms. The floral scents ofAmmandra dasyneura, A. decasperma, Aphandra natalia, Phytelephas aequatorialis, P. macrocarpa, andP. seemannii were analyzed by gas chromatography-mass spectrometry. We studied the pollination biology ofA. natalia, P. aequatorialis, andP. macrocarpa, and tested how the synthetically produced main constituents of the floral scents ofAphandra andPhytelephas attracted insects in two natural populations ofPhytelephas. The genera are distinct in terms of floral scents.Ammandra has sesquiterpenes,Aphandra (+)-2-methoxy-3-sec-butylpyrazine, andPhytelephas p-methyl anisol. These constituents dominated the scents quantitatively and qualitatively. The similarity between scents of male and female inflorescences was 76.5% inAmmandra, 84.2% inAphandra, and >99% inPhytelephas. Different species ofAleocharinae (Staphylinidae) pollinateAphandra natalia andPhytelephas species and reproduce in their male inflorescences.Derelomini (Curculinoidae) andMystrops (Nitidulidae) only visit and pollinatePhytelephas in which male inflorescences they reproduce. A species ofBaridinae (Curculionidae) only visits and pollinatesAphandra natalia, and reproduces in its female inflorescence. The apparent reliance on one or a few floral scent constituents as attractants and few and specific pollinators may indicate co-evolution. Sympatric species ofPhytelephantoideae have different scents. We suggest that species with similar scents have allopatric distributions due to the absence of a pollinator isolation mechanism.     

Floral homeotic gene expression defines developmental arrest stages inBrassica oleracea L. vars.botrytis anditalica

Brassica oleracea L. vars.italica (broccoli) andbotrytis (cauliflower) both undergo developmental arrests which result in heading phenotypes. We characterized these arrested tissues at the morphological and molecular levels, and defined the developmental changes that ensue after arrest has been broken. We found that the order of floral organ initiation and the positions of resulting floral organ primordia in this species differed in some respects from that ofArabidopsis, which is a member of the same family, Brassicaceae. We also cloned homologs of theArabidopsis floral homeotic genesAPETALA1 (AP1) andAPETALA3 (AP3) fromB. oleracea and characterized their expression patterns. We found that theAP1 homolog was expressed in some of the meristems of arrest-stage cauliflower, providing evidence that this tissue is florally determined. In broccoli, both the API andAP3 homologs were expressed. However, the spatial pattern of expression of the broccoliAP1 homolog differed from that ofArabidopsis. In addition, we identified a homolog of theCAULIFLOWER (CAL) gene,BoiCAL, from broccoli. The predicted amino acid sequence indicated that theBoiCAL gene product does not contain the mutation thought to be responsible for the early arrest exhibited in cauliflower (Kempin et al. 1995), but contains other changes that might play a role in the broccoli heading phenotype.The GenBank accession numbers for the sequences reported here are: U67451 (Boi2AP1); U67452 (Boi2AP1); U67453 (Boi1AP3); U67455 (Boi2AP3); U67456 (BobAP3); and U67454 (BoiCAL)