Exploitation of floral resources on Sparattosperma leucanthum (Bignoniaceae): foraging activity of the pollinators and the nectar and pollen thieves

The interaction between floral visitors and plants in natural ecosystems has become a major subject in studies on biodiversity conservation. However, there is a very complex interaction between the community of floral visitors and the plant species foraged by them in the natural environment and little is known about the foraging activity of these visitors. Thus, the objective of this study was to determine the composition of the community of floral visitors to Sparattosperma leucanthum in an area under natural regeneration, focusing on the assessment of the exploitation of floral resources by the predominant visitors and effective pollinators. To accomplish this objective, we recorded the activity and behavior of the floral visitors throughout the day in a 2- to 3-m² area of flowering branches of S. leucanthum. The model established in the current study comprises the occurrence of a high number of species with few individuals, whereas few species are represented by many individuals. The five predominant species were Apis mellifera, Trigona spinipes, Bombus sp1, Hylocharis chrysura, and Halictidae type 1. Of these species, only Bombus sp1 seemed to effectively pollinate the flowers.     

The identity of Ctenophrynium K. Schum. (Marantaceae)

Ctenophrynium unilaterale (Baker) K. Schum. was described from cultivated material reported to have been brought from Madagascar. It has recently been recollected in the state of Bahía, SE Brazil. A reexamination shows good agreement with the Brazilian genus Saranthe (Regel & Koern.) Eichl. The recombination Saranthe unilateralis (Baker) L. Anderss. is made and the genus Ctenophrynium is reduced to a synonym of Saranthe . The plant is redescribed and illustrated.     

The selective use of floral resources by the hoverfly Episyrphus balteatus (Diptera: Syrphidae) on farmland

The use of flowers of non-crop plants by the syrphid Episyrphus balteatus in margins of cereal fields was assessed quantitatively. G-tests and the ‘C’ index of Murdoch (1969) were used to compare the use and abundance of twenty-seven plant species by adult flies from June to August in the UK. The flowers of several plant species were used selectively by hoverflies throughout the season while the relative importance of others changed with date. The prospects for managing the field-margin flora to enhance biocontrol by hoverflies is discussed.     

Relationship between floral traits and floral visitors in two coexisting Tecoma species (Bignoniaceae)

In this paper, we studied the floral biology of Tecoma fulva ssp. garrocha and T.?stans in Vaqueros (Salta, Argentina), where both species coexist. We tested the idea that floral traits are associated with the pollinator types that visit them. According to our results, T.?fulva ssp. garrocha presented traits common to bird flowers and were visited by two species of Trochilidae (Colibri serrirostris and Chlorostilbon lucidus). In addition, T.?stans exhibited traits common to hymenoptera flowers and were visited principally by Apis mellifera and Bombus atratus. This study showed that floral traits are predictive of animal visitors.     

A tetrahydro beta-carboline trisaccharide from Palicourea coriacea (Cham.) K. Schum

A new tetrahydro beta-carboline alkaloid that has an oligosaccharide unit was isolated from the root extracts of the Palicourea coriacea. The structure was elucidated using spectral methods, including 2D NMR: COSY, HMQC, HMBC and NOESY.     

Pollination of Adenocalymma bracteatum (Bignoniaceae): floral biology and visitors

Adenocalymma bracteatum is a shrub of dense foliage and yellow flowers, easily found on grasslands areas in Central Brazil. The aim of this study was to determine the reproductive biology and the flower visitors of A. bracteatum in a pasture area nearby Ivinhema city, MS (Brazil). The flowering peak occurs in winter. The flower reflects ultraviolet light. Anthesis begins at 6:30h, and pollen and nectar are the resources to visitors. We captured 1,038 floral visitors. The bees Apis mellifera (L.), Trigona sp., Trigona spinipes (Fabricius), (Hymenoptera: Apoidea) and the ant Cephalotes sp. (Hymenoptera: Formicidae) were the main visitors. The reproductive tests indicate that A. bracteatum is self compatible, justifying its expansion in altered environments; however, the largest reproductive success was dependant on cross-pollination and self-pollination, evidencing the pollinators importance. Adenocalymma bracteatum presents melittophilous syndrome and bumblebees were the main pollinators in the area. The correlations observed between the climatic variables and the main pollinator species were low or medium.     

Evolution of floral morphology and pollination system in Bignonieae (Bignoniaceae)

The radiation of angiosperms is associated with shifts among pollination modes that are thought to have driven the diversification of floral forms. However, the exact sequence of evolutionary events that led to such great diversity in floral traits is unknown for most plant groups. Here, we characterize the patterns of evolution of individual floral traits and overall floral morphologies in the tribe Bignonieae (Bignoniaceae). We identified 12 discrete traits that are associated with seven floral types previously described for the group and used a penalized likelihood tree of the tribe to reconstruct the ancestral states of those traits at all nodes of the phylogeny of Bignonieae. In addition, evolutionary correlations among traits were conducted using a maximum likelihood approach to test whether the evolution of individual floral traits followed the correlated patterns of evolution expected under the "pollination syndrome" concept. The ancestral Bignonieae flower presented an Anemopaegma-type morphology, which was followed by several parallel shifts in floral morphologies. Those shifts occurred through intermediate stages resulting in mixed floral morphologies as well as directly from the Anemopaegma-type morphology to other floral types. Positive and negative evolutionary correlations among traits fit patterns expected under the pollination syndrome perspective, suggesting that interactions between Bignonieae flowers and pollinators likely played important roles in the diversification of the group as a whole.     

Anther ontogeny in Campsis radicans (L.) Seem. (Bignoniaceae)

In this study anther ontogeny of Campsis radicans (L.) Seem. was investigated by transmission electron microscopy and light microscopy with special reference to the development of the anther wall. The anther wall formation follows the dicotyledonous type. The differentiation in anther starts with the appearance of archesporial cells which undergo periclinal divisions to give primary parietal layer to the epidermal site and the primary sporogenous cells to the inside. The primary parietal layer also divides to form two secondary parietal layers. Later, the outer secondary parietal layer (spl1) forms the endothecium and the middle layer by periclinal division whereas the inner one (spl2) directly develops into the outer tapetum forming the inner most layer of the anther wall. The sporogenous tissue is generally organized in two rows of cells with a horseshoe-shaped outline. The remainder of the tapetum lining the sporogenous mass is derived from the connective tissue. The tapetum thus has dual origin and dimorphic. Anthers are tetrasporangiate. The wall of the anther consists of an epidermis, endothecium, middle layer, and the secretory type tapetum. Tapetal cells are usually binucleated. Epidermis and Endothecium layers of anther wall remain intact until the end of anther and pollen development; however, middle layer and tapetum disappear during development.     

山姜属中药草豆蔻和益智nrDNA ITS区序列的测定

中药草豆蔻、益智的原植物分别为山姜属草豆蔻（Ａｌｐｉｎｉａ ｈａｉｎａｎｅｎｓｉｓ Ｋ．Ｓｃｈｕｍ．）与益智（Ａ．ｏｘｙｐｈｙｌａ Ｍｉｑ．）。本文采用ＰＣＲ直接测序法,首次测定了它们的核糖体ＤＮＡ ＩＴＳ区序列。结果显示,两者序列长度（ＩＴＳ１＋ＩＴＳ２）分别为４０３ｂｐ与４０４ｂｐ,序列间具有２７个变异位点（包括５．８Ｓ编码区）。本研究为山姜属中药材的ＤＮＡ分子鉴定提供了必要的序列资料。     

Chemical profile of Eriocaulon ligulatum (Vell.) L.B. Smith (Eriocaulaceae)

Two new and six known flavonoids and two known naphthopyranones have been isolated by chromatographic methods and spectrometrically identified in capitulae and scapes of Eriocaulon ligulatum (Vell.) L.B. Smith (Eriocaulaceae). The presence of naphthopyranones suggests approximation between Eriocaulon and Paepalanthus genus.     

In vitro propagation of Rudraksha (Elaeocarpus sphaericus (Gaertn.) K. Schum): a biotechnological approach for conservation

The species Elaeocarpus sphaericus (Rudraksha) is a religious, medicinally important threatened tree of India. An efficient micropropagation protocol has been developed from nodal explants of this plant species collected from north-east India for large scale production of planting material at favourable sites within the country. Best shoot initiation occurred in MS medium supplemented with 2.2μM BA+2.2μM Kn in combination. Addition of Casein Hydrolysate (CH) (100mg/L) increased the shoot number. Microshoots excised and subcultured in 2.0μM BA further enhanced growth and multiplication. The shoot cultures were maintained in this concentration for 2years with subculturing at 6weeks interval. MS medium containing 5.0μM NAA was most effective for rooting. Successfully acclimatized plants (80%) showed normal growth under suitable habitat conditions.     

The Wood Parenchyma of Triplochiton scleroxylon K. Schum

Unusual features in the histology of the secondary xylem wererevealed during an investigation into growth-ring developmentin Triplochiton in Nigeria. The main observation was the presenceof two kinds of apotracheal parenchyma: (1) strands made uplongitudinally of 2 to 4 (occasionally more) cells containingstarch and, (2) empty fusiform strands, without cross-walls.Each kind of parenchyma formed ‘units’, i.e. uniseriatetangential rows of like strands between the wood-rays. The starchystrands (storage parenchyma) became more numerous towards theend of each growth ring.     

In vitro propagation ofHolostemma annulare (Roxb.) K. Schum., a rare medicinal plant

Summary A rapid micropropagation system was established forHolostemma annulare (Roxb.) K. Schum., (H. ada-kodien R. Br. ex Schult; Asclepiadaceae), a rare medicinal plant. Shoot tips (0.5–0.8 cm) and terminal and basal nodes (1.0–1.5 cm) harvested from actively growing shoots of conventionally raised plants were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of 6-benzyladenine (BA) and α-naphthaleneacetic acid (NAA). Multiple shoot formation (3.8) was observed in 68% of basal nodes cultured on medium with optimum concentration of 4.43 μM BA and 0.54 μM NAA after 8 wk. Terminal nodes were not suitable for inducing multiple shoots. Irrespective of the orientation (vertical/horizontal), all shoot tip explants responded with a single shoot in all the combinations of plant growth regulators tried. Effects of other cytokinins (kinetin and 2-isopentenyladenine) and auxins [indole-3-acetic acid and indole-3-butyric acid (IBA)] to enhance the regeneration potential of basal nodes were analyzed. Shoots were multiplied by subculture of basal nodes and stumps (the original explant tissue free of shoots, but with remnant axillary, meristem and two or three protruding buds) in a reduced concentration of BA (2.21 μM) and NAA (0.27 μM). Liquid medium for multiplication was found to be ineffective due to a high degree of hyperhydricity. To make the multiplication process cost effective, culture bottles with polypropylene, caps were used for multiplication. The best root induction (75%) and survival (80%) was achieved on 0.5 strength MS medium supplemented with 1.48 μM IBA. Field-established plants had uniform growth habit traits in terms of height of plants and number, length, and weight of the tuberous roots.     

Cytochemistry of pollen development in Campsis radicans (L.) Seem. (Bignoniaceae)

In this study, cytochemical staining methods were used to follow the cytochemical modifications of microspore cytoplasm and sporoderm in Campsis radicans (L.) Seem. from tetrad stage to mature pollen. Flower buds were collected at different stages of development, and the anthers were fixed and embedded in Araldite. To make cytochemical observations under light microscope, semithin sections were cut and stained with different dyes. Cytochemical methods provided the opportunity to localize the reserve material in the microspore and pollen cytoplasm, to distinguish the different layers of the sporoderm, and to determine its chemical structure at different developmental stages. Microspore cytoplasm contains variable amounts of proteins, lipids, and insoluble carbohydrates at different stages of microsporogenesis. Sporoderm formation starts at tetrad stage by the formation of primexine and is completed at vacuolated microspore stage by the addition of sporopollenin from tapetum. During the vacuolization and enlargement of the microspores, the structure and the chemical composition of the exine are modified. The endexine becomes chemically different from the ectexine. The ectexine is composed of sporopollenin and a small amount of protein, whereas the endexine is composed of sporopollenin, proteins, and traces of polysaccharides.     

Cytogenetic characterization of embryogenic callus and regenerated plants of Pennisetum americanum (L.) K. Schum

Summary Embryogenic calli were derived from cultured segments of immature inflorescences of Pennisetum americanum (pearl millet). The original explants as well as the embryogenic calli and the plants regenerated via somatic embryogenesis were examined cytogenetically. Embryogenic calli were predominantly diploid (2n=14) after one month and six months in culture (92% and 76%, respectively). Tetraploid and aneuploid cells were observed in the original explant (2.5% and 1.2%) as well as in one (4.0% and 4.0%) and six-month-old calli (10.0% and 14.0%). Plants were regenerated from calli that had been in continuous culture for two, four and six months. Of the 101 regenerants, 100 were diploid and 1 was tetraploid. The tetraploid was an albino as were three of the diploid regenerants. Examination of 30 of the regenerants in meiotic diakinesis, anaphase I, anaphase II and quartet stages revealed no cytogenetic differences between control and regenerated plants. Gel electrophoresis for total protein content and alcohol dehydrogenase and malate dehydrogenase activity also did not reveal any differences between the controls and regenerants. The results of this study show that a slight shift toward aneuploidy and polyploidy may occur in embryogenic cultures, but there also is a strong selection in favor of plant regeneration from cytogenetically normal cells.     

Tertiary trisomics of pearl millet (Pennisetum americanum (L.) K. Schum): its cytomorphology,fertility and transmission

Summary Nineteen tertiary trisomics were isolated from some translocation heterozygotes and interchange trisomics of pearl millet. Cytological analysis of these trisomics indicates that chromosome association of trivalents, univalents and pentavalents were frequent in all the trisomics. But their ratio varied from one trisomic to the next. Other associations were relatively infrequent. The relative frequencies of 6 pentavalent configurations observed in different trisomics were studied and their probable association with mode of fertility and transmission rates have been discussed.     

Safrole Analysis by GC-MS of Prototrophic (Ocotea odorifera (Vell.) Rohwer) Cell Cultures

Ocotea odorifera, a tree native to the Atlantic rainforest in south Brazil, has been used as a source of sassafras oil rich in safrole [5-(2-propenyl)-1,3-benzodioxole], an aromatic ether used as a flavoring agent and also in the manufacture of insecticides. The intensive deforestation process of the Brazilian Atlantic rainforest has threatened with extinction some species including O. odorifera. In this context, O. odorifera cell cultures might be an interesting alternative for the production of secondary metabolites of value (i.e., safrole), without risk of damage to the native germplasm. Insights into the secondary metabolites of organosolvent extracts of prototrophic cell cultures were performed by GC-MS and MALDI-TOF MS. GC-MS analysis revealed the occurrence of safrole in concentration of ca. 62.6 μg ml⁻¹ and allowed the identification of other compounds besides safrole in the crude extract of these cultures. Thus, alkyl phenol (C₈) [m/z= 206], C₁₄ myristic acid [m/z= 228], long chain olefin or alcohol and essential oil were detected. However, safrole [m/z= 162] was not detected by MALDI-TOF MS, indicating that it is not easily protonated (M + H)⁺.     

Ontogenesis secretion and senescence of Tocoyena bullata (Vell.) Mart. (Rubiacaeae) colleters

Colleters are secretory structure present on many families including Rubiaceae. Particular characteristics have been described about colleters secretory cells, however senescence process are still under debate. Tocoyena bullata (Vell.) Mart. (Rubiaceae) shoot apex were collected at Jardim Botânico do Rio de Janeiro, RJ/Brazil. Stipules were separated and fragments were fixed in 2.5% glutaraldehyde and 4.0% formaldehyde in 0.05 m sodium cacodylate buffer, pH 7.2, post fixed in 1.0% osmium tetroxide in the same buffer, dehydrated in acetone, critical‐point‐drying, sputtered coated and observed. For light microscopy fragments were fixed and dehydrated, infiltrated with historesin and stained with 1% toluidine blue. For transmission electron microscopy, the samples were infiltrated with Epoxi resin. Colleters are present on stipule adaxial surface. On the beginning of development, these structures are recognized as small projections. Later on, colleters differentiated and secrete by cuticle rupture. The colleters senescence occurs in a concomitant and indissoluble way of programmed cell death. Ultrastructural analyses during the process strongly suggest the senescence is based on a non‐autolitic programmed cell death. T. bullata colleters, present at stipule abaxial surface are cylindrical secretory structures. Colleters secretory cells originated as stipule projections; differentiate; secrete and senesce by programmed cell death. The secretion and the cell dead occurs in a concomitantly and indissoluble way.