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Inflorescences
Terms modified by Inflorescences Selected AbstractsVariation in Floral Sex Allocation and Reproductive Success in Sequentially Flowering Inflorescence of Corydalis remota var. lineariloba (Fumariaceae)JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 3 2009Yan-Fei Zeng Abstract In hermaphroditic plants, female reproductive success often varies among different positions within an inflorescence. However, few studies have evaluated the relative importance of underlying causes such as pollen limitation, resource limitation or architectural effect, and few have compared male allocation. During a 2-year investigation, we found that female reproductive success of an acropetally flowering species, Corydalis remota Fisch. ex Maxim. var. lineariloba Maxim. was significantly lower in the upper late developing flowers when compared with the lower early flowers. Supplementation with outcross pollen did not improve female reproductive success of the upper flowers, while removal of the lower developing fruits significantly increased female reproductive success of the upper flowers in both years, evidencing resource limitation of the upper flowers. Female production in upper flowers was greatly improved by simultaneous pollen supplementation of the upper flowers and removal of the lower fruits, suggesting that, when resources are abundant, pollen may limit the female reproductive success of the upper flowers. The less seed mass in the upper flowers didn't increase in all treatments due to architecture. In the upper flowers, ovule production was significantly lower and the pollen : ovule ratio was significantly higher. These results suggest that male-biased sex allocation in the upper flowers may lead to increased male reproductive success, whereas the lower flowers have higher female reproductive success. [source] Caladium bicolor (Araceae) and Cyclocephala celata (Coleoptera, Dynastinae): A Well-Established Pollination System in the Northern Atlantic Rainforest of Pernambuco, BrazilPLANT BIOLOGY, Issue 4 2006A. C. D. Maia Abstract: Flowering, pollination ecology, and floral thermogenesis of Caladium bicolor were studied in the Atlantic Rainforest of Pernambuco, NE Brazil. Inflorescences of this species are adapted to the characteristic pollination syndrome performed by Cyclocephalini beetles. They bear nutritious rewards inside well-developed floral chambers and exhibit a thermogenic cycle which is synchronized to the activity period of visiting beetles. Heating intervals of the spadix were observed during consecutive evenings corresponding to the beginning of the female and male phases of anthesis. Highest temperatures were recorded during the longer-lasting female phase. An intense sweet odour was volatized on both evenings. Beetles of a single species, Cyclocephala celata, were attracted to odoriferous inflorescences of C. bicolor and are reported for the first time as Araceae visitors. All the inflorescences visited by C. celata developed into infructescences, whereas unvisited inflorescences showed no fruit development. Findings of previous studies in the Amazon basin of Surinam indicated that Cyclocephala rustica is a likely pollinator of C. bicolor. This leads to the assumption that locally abundant Cyclocephalini species are involved in the pollination of this species. [source] Berry infection and the development of bunch rot in grapes caused by Aspergillus carbonariusPLANT PATHOLOGY, Issue 2 2008B. A. Kazi The effects of different levels of inoculum of Aspergillus carbonarius and time of inoculation on berry infection and the development of aspergillus bunch rot on grapevines (cv. Sultana) were studied under field conditions. Inflorescences at full bloom were inoculated with aqueous spore suspensions of A. carbonarius containing 0 or 1 × 106 spores mL,1 in 2004/05 and 0, 1 × 102 or 1 × 105 spores mL,1 in 2005/06. In both years, the incidence of infection in inoculated berries was significantly higher than in uninoculated berries. Incidence of infection in berries from veraison until harvest was higher than at earlier stages of bunch development (berry set to berries that were still hard and green). Inoculation of bunches at veraison did not significantly increase A. carbonarius infection prior to harvest, at harvest, 6 days after harvest or when berries were over-ripe. Bunches inoculated at harvest did not significantly increase infection 6 days after harvest or when berries were over-ripe. Aspergillus carbonarius was isolated more frequently from the pedicel end (53·1%) than from the middle section (37·5%) and distal end (35·0%) of berries that were inoculated with 105 spores mL,1. [source] Functional significance of the dark central floret of Daucus carota (Apiaceae) L.; is it an insect mimic?PLANT SPECIES BIOLOGY, Issue 2 2009DAVID GOULSON Abstract In Daucus carota L. (Apiaceae) the florets comprising the central umbellet of inflorescences are usually pink or dark purple, presenting a marked contrast to the surrounding umbellets, which are generally white. The number of dark florets varies, and some inflorescences have no dark florets. It has been proposed that the dark florets function as an insect mimic, and in so doing serve to attract insects to the flower. In contrast, other authors, Darwin included, suggest that they are functionally redundant. The present study examined whether the dark florets attract insects, and also whether this effect can be replicated by replacing these florets with an insect. At the study site in Portugal the predominant insect visitor was the beetle Anthrenus verbasci L. (Dermestidae), which is similar in size and shape to the dark florets. Large inflorescences and those with more dark florets attracted more beetles than small inflorescences and those with fewer or no dark florets. Inflorescences with the dark florets removed attracted fewer beetles visitors compared with intact inflorescences. Inflorescences in which the dark florets were replaced with one or a cluster of five dead, freeze-killed A. verbasci attracted more beetles than inflorescences from which the dark florets had been removed. Replacement of the dark florets with a relatively large Meloid beetle resulted in the attraction of markedly fewer A. verbasci. We conclude that the dark florets can act as an insect attractant for some insect groups by acting as an insect mimic, and that they are adaptive, in contrast to the speculations of Darwin. [source] Density, dispersal, and feeding impact of western flower thrips (Thysanoptera: Thripidae) on flowering chrysanthemum at different spatial scalesECOLOGICAL ENTOMOLOGY, Issue 1 2005Marc Rhainds Abstract., 1. This study evaluated the effect of dispersal on the density and feeding impact of a phytophagous insect in relation to the spatial distribution of its host plants. 2. The interaction between density, dispersal, and feeding impact of western flower thrips on flowering chrysanthemum was quantified at three spatial scales, with infested and uninfested plants either isolated in 0.25 m2 individual cages, or enclosed together in 2.25 m2 communal cages or 75 m2 greenhouses. 3. In individual cages, the rate of dispersal from chrysanthemum plants to blue sticky traps increased with the density of thrips for females but not males. Uninfested plants consistently had fewer thrips when they were individually caged rather than enclosed with plants infested with adults, indicating that dispersal mediates inter-plant distribution of thrips. 4. The feeding impact of thrips on inflorescences was evaluated using the absorbance of ethanol extracts at wavelengths characteristic of yellow carotenoid pigments associated with chrysanthemum inflorescences (415, 445, and 472 nm). Increasing absorbance of extracts with increasing density of thrips per inflorescence suggests that feeding by thrips results in ruptured cells leaching carotenoid pigments. 5. In communal cages, the distribution of thrips was uniform for infested and uninfested plants, whereas the density and feeding impact of thrips in greenhouses were higher for infested than uninfested plants. These results suggest that short-range dispersal by adults homogenises the density and feeding impact of thrips among host plants only on a small spatial scale. [source] Insect colonisation sequences in bracts of Heliconia caribaea in Puerto RicoECOLOGICAL ENTOMOLOGY, Issue 4 2000Barbara A. Richardson Summary 1. It was predicted that insects colonising Heliconia phytotelmata would exploit the different bract conditions along inflorescences, which result from sequential ageing. 2. Flowering of H. caribaea is asynchronous over a 6-month period. A method of identifying bracts of the same age, regardless of position on the inflorescence or inflorescence age, and from different plants over 2 years, was developed using comparative flowering phenology. 3. Heliconia insect larval communities were remarkably consistent from year to year in species composition and relative abundance. Occurrence within the plant population was also similar from year to year, and most species were Heliconia specific. 4. Significant interspecific differences were found in bract utilisation, with populations peaking at different stages of bract development. Ceratopogonid larvae were the earliest colonisers, followed by psychodids, syrphids, and culicids. Tipulids occurred much later in the cycle of bract development and ageing. These patterns were consistent in both years. 5. Patterns of bract utilisation provide strong support for temporal niche partitioning by variation in oviposition and development time. Communities were not considered to be structured by predation or pH changes along the bract sequence. [source] Pollination mutualism between a new species of the genus Colocasiomyia de Meijere (Diptera: Drosophilidae) and Steudnera colocasiifolia (Araceae) in Yunnan, ChinaENTOMOLOGICAL SCIENCE, Issue 1 2006Kohei TAKENAKA Abstract A new species of the genus Colocasiomyia de Meijere (Diptera: Drosophilidae) was discovered from inflorescences of Steudnera colocasiifolia K. Koch (Araceae) in Yunnan, China. The new species is described as Colocasiomyia steudnerae Takenaka and Toda, sp. nov., and we investigated the reproductive ecology of both the fly and the plant species. This fly species reproduces in the inflorescences/infructescences of the plant, and depends almost throughout its entire life cycle on the host plant. The fly species is the most abundant flower visitor for S. colocasiifolia and behaves intimately with the flowering events, suggesting that it is the unique and most efficient pollinator for the host plant. Bagging (insect-exclusion) treatment of inflorescences resulted in no fruits. These findings strongly suggest that intimate pollination mutualism has evolved between the fly and the host plant, as are known in other Colocasiomyia flies and Araceae plants. One notable feature of this system is that the new species almost monopolizes the host-plant inflorescence as a visitor, without any cohabiting Colocasiomyia species. In comparison to other cases where two Colocasiomyia species share the same inflorescence and infructescence of Araceae host plants for reproduction by separating their breeding niches microallopatrically between the staminate (upper male-flower) and the pistillate (lower female-flower) regions on the spadix, C. steudnerae exhibits a mixture of stamenicolous and pistillicolous breeding habits. [source] EVOLUTION OF REPRODUCTIVE STRATEGIES IN THE SEXUALLY DECEPTIVE ORCHID OPHRYS SPHEGODES: HOW DOES FLOWER-SPECIFIC VARIATION OF ODOR SIGNALS INFLUENCE REPRODUCTIVE SUCCESS?EVOLUTION, Issue 6 2000Manfred Ayasse Abstract The orchid Ophrys sphegodes Miller is pollinated by sexually excited males of the solitary bee Andrena nigroaenea, which are lured to the flowers by visual cues and volatile semiochemicals. In O. sphegodes, visits by pollinators are rare. Because of this low frequency of pollination, one would expect the evolution of strategies that increase the chance that males will visit more than one flower on the same plant; this would increase the number of pollination events on a plant and therefore the number of seeds produced. Using gas chromatography-mass spectrometry (GC-MS) analyses, we identified more than 100 compounds in the odor bouquets of labellum extracts from O. sphegodes; 24 compounds were found to be biologically active in male olfactory receptors based on gas chromatography with electroantennographic detection (GC-EAD). Gas chromatography (GC) analyses of odors from individual flowers showed less intraspecific variation in the odor bouquets of the biologically active compounds as compared to nonactive compounds. This can be explained by a higher selective pressure on the pollinator-attracting communication signal. Furthermore, we found a characteristic variation in the GC-EAD active esters and aldehydes among flowers of different stem positions within an inflorescence and in the n-alkanes and n-alkenes among plants from different populations. In our behavioral field tests, we showed that male bees learn the odor bouquets of individual flowers during mating attempts and recognize them in later encounters. Bees thereby avoid trying to mate with flowers they have visited previously, but do not avoid other flowers either of a different or the same plant. By varying the relative proportions of saturated esters and aldehydes between flowers of different stem positions, we demonstrated that a plant may take advantage of the learning abilities of the pollinators and influence flower visitation behavior. Sixty-seven percent of the males that visited one flower in an inflorescence returned to visit a second flower of the same inflorescence. However, geitonogamy is prevented and the likelihood of cross-fertilization is enhanced by the time required for the pollinium deposited on the pollinator to complete its bending movement, which is necessary for pollination to occur. Cross-fertilization is furthermore enhanced by the high degree of odor variation between plants. This variation minimizes learned avoidance of the flowers and increases the likelihood that a given pollinator would visit several to many different plants within a population. [source] De Liliifloris Notulae 8.FEDDES REPERTORIUM, Issue 3-4 2010Two new Massonia species (Hyacinthaceae) from South Africa Abstract A re-investigation of the Stockholm paratype of Massonia tenellaSoland. ex Baker 1871, Drège 3509 (K, S!) from Witbergen (,3027CA, Lady Grey) in the Eastern Cape in combination with the study of a living seedling leaf from a second locality confirmed our cautious earlier suggestion (U. & D. Müller-Doblies 1997) that it is a new species. Massonia wittebergensis U.Müll.-Doblies & D.Müll.-Doblies has a unique leaf indument in Massonieae of laterally compressed curved emergences in Drège's herbarium specimen. Living emergences of a seedling leaf are less laterally compressed. Living and herbarium emergences share a further unique detail: the rounded tip is uneven with projecting cells. As to the distribution, M. tenella is only known from the Bokkeveld escarpment (Western Cape, Baker 1897), whereas M. wittebergensis occurs in the Drakensberge eight degrees longitude further east in the Eastern Cape. As to the second species treated here, a closer investigation of a leaf and a withered fresh inflorescence showed that it is a new species too: Masso- nia sempervirens U.Müll.-Doblies, G.Milkuhn & D.Müll.-Doblies. The retired horticulturist, Gottfried Milkuhn (Dresden), had received this enigmatic remarkable evergreen Massonia species in 2007 from a Dutch succulent grower as "Whiteheadia jasminiflora " from Prince Albert (Western Cape) (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Geranium jaramilloi (Geraniaceae), a new species from ColombiaFEDDES REPERTORIUM, Issue 5-6 2009C. Aedo A new species of Geranium L. (Geraniaceae), Geranium jaramilloi Aedo, sp. nova, is described and illustrated. The new species is morphologically most similar to G. santanderiense and G. lainzii. Geranium jaramilloi is easily distinguished by its leaves with entire segments (3-lobed in G. santanderiense), and with abundant, patent, long and stout, eglandular hairs on both surfaces, although restricted to nerves abaxially (usually glabrous, and with a noticeable ciliate margin in G. santanderiense). Leaves also distinguished very well G. jaramilloi from G. lainzii, having the latter subtruncate leaves with 3-lobed segments and scattered hairs near leaf margin. The new species belongs to sect. Gracilia, a group endemic to Colombia and Venezuela, characterized by its herbaceous and well developed stem, 2-flowered cymules and inflorescence with dichasial branching. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Notes on South American Valerianaceae I,FEDDES REPERTORIUM, Issue 7-8 2003F. Weberling Professor Dr. A new species of Belonanthus, Belonanthus theodorici sp. nova, is described. It is characterized by spathulate foliage leaves, the ovate blades of which are rather distinctly contracted into a long and narrow sheathing petiole and bear a dense covering with long hairs, giving the surface of the rosette a silvery sheen. In the monothyrsoid inflorescence the peduncles (hypopodia) of the lower partial inflorescences are considerably elongated. , Valeriana micropterinaWedd., V. poterioidesGraebn., V. thalictroidesGraebn. and V.aspleniifoliaKillip are included into Valeriana microptera. , For Valeriana fonkiiPhil. and V. radicalisClos reliable distinctive characters are named. , For Valeriana decussataRuiz & Pav. virescent calices with green sepals are described and illustrated. Anmerkungen zu südamerikanischen Valerianaceae I Es wird eine neue Belonanthus -Art aus Peru, Belonanthus theodorici sp. nova beschrieben. Diese ist gekennzeichnet durch ihre silberhaarigen Laubblätter und den Bau ihrer Infloreszenzen, deren cymöse Partialinfloreszenzen teilweise mit langgestreckten Hypopodien ausgestattet sind. Valeriana micropterinaWedd., V. poterioidesGraebn., V. thalictro-idesGraebn. und V. aspleniifoliaKillip sind unter dem Namen der erstgenannten vereinigt. Für Valeriana fonkiiPhil. und V. radicalisClos werden verlässliche Unterscheidungsmerkmale genannt. Vergrünte, mit sepaloiden Kelchblättern ausgestattete Kelche werden für Valeriana decussataRuiz & Pav. beschrieben und abgebildet. [source] Essential oil composition of Pimpinella affinis Ledeb. from two localities in IranFLAVOUR AND FRAGRANCE JOURNAL, Issue 5 2006F. Askari Abstract Essential oils were isolated by hydrodistillation from the stems plus leaves, inflorescences and seeds of Pimpinella affinis Ledeb. individually. The plants were collected from Khojir and Chaloos (north-east and north of Tehran province, respectively). The yields of stem plus leaf, inflorescence and seed oils for the Khojir samples were 0.04%, 1.98% and 5.33% w/w and for the Chalous samples were 0.37%, 1.74% and 4.05% w/w, respectively. Limonene is a major constituent in the inflorescence and seed oils of the Khojir (47.9% and 90.5%, respectively) and Chalous samples (37.8% and 70.8%, respectively), whereas it was found in the stem plus leaf oil of the Khojir and the Chalous samples in low amounts (1.4% and 0.8%, respectively). , -Terpinen-7-al is the major constituent in the stem plus leaf and inflorescence oils of the Khojir (69.9% and 37.6%) and Chalous samples (72.8% and 49.1%), but was not found at all in the seed oils. Caryophyllene oxide (9.1%) was found in the stem plus leaf oil of the Khojir sample, and methyl eugenol (9.7%) and (E)-nerolidol acetate (9.1%) in the seed oil of the Chalous sample. Copyright © 2006 John Wiley & Sons, Ltd. [source] Thermogenesis and respiration of inflorescences of the dead horse arum Helicodiceros muscivorus, a pseudo-thermoregulatory aroid associated with fly pollinationFUNCTIONAL ECOLOGY, Issue 6 2003R. S. Seymour Summary 1In central Corsica, Helicodiceros muscivorus (Schott ex. K. Koch) produces a protogynous inflorescence that resembles the anal area of a dead mammal and produces a foetid scent during the few hours after sunrise. Flies enter the floral chamber, pollinate the female florets and become trapped until the next morning, when pollen is shed from the male florets and the flies are released. 2The exposed appendix exhibits a strong, unimodal episode of thermogenesis associated with scent production, reaching a maximum of 30 °C at 15 °C ambient temperature. The male florets in the floral chamber are highly thermogenic throughout the second night and generally maintain stable floret temperatures of about 24 °C at ambient temperatures down to 13 °C. 3Maximum respiration rates of the appendix (0·45 µmol CO2 s,1 g,1) and the male florets (0·82 µmol s,1 g,1) may be the highest recorded for plant tissue. 4Thermogenesis of the appendix does not depend on ambient temperature, but that of the male florets increases with decreasing ambient temperature in most cases. However, the pattern of heat production by the males appears related more to time than to ambient temperature, hence the term ,pseudo-thermoregulation'. 5The behaviour and thoracic temperatures of flies emerging from captivity suggests that male floral warming does not enhance their activity. [source] Nectar ,theft' by hummingbird flower mites and its consequences for seed set in Moussonia deppeanaFUNCTIONAL ECOLOGY, Issue 1 2001Lara C. Summary 1,Mites (Acari: Mesostigmata: Ascidae) that live and feed in the flowers of about 100 plant species are transported in the nares of hummingbirds (Trochilidae). Mites may compete with hummingbirds for nectar secreted by the host plants, and this could affect the dynamics and reproductive outcomes of the mutualism between plants and their pollinating hummingbirds. 2,Here we combined field observations and experimental manipulations to assess the role of hummingbird flower mites (Tropicoseius sp. nov.) on nectar secretion and reproductive output of protandrous Moussonia deppeana (Schlecht. & Cham.) Hanst. (Gesneriaceae) during their flowering period in a cloud forest remnant. 3,During the 4 days that the flowers of M. deppeana last, flowers were visited exclusively by hummingbirds (Lampornis amethystinus). Bud production per inflorescence peaked in December. There were few open flowers per inflorescence in November, but numbers increased as the flowering season progressed (December and January). 4,The availability of each flower phase differed over the flowering season. Staminate-phase flowers were more abundant over the flowering season than pistillate-phase flowers. These differences were statistically significant over time. 5,Nectar availability was reduced by up to 50% in the presence of hummingbird flower mites. Over the 4 days of observation, significantly more nectar was secreted to flowers from which mites were excluded than to flowers with no mite exclusion. The same effect was observed during flowering, but mites consumed a greater percentage of the total nectar secreted in December. 6,Significantly more nectar was secreted during the staminate phase than in the pistillate phase, independent of time and treatment. 7,A manual pollination experiment suggested that mites act like secondary pollinators in this self-compatible, non-autogamous plant, at least in flowers that were not pollinated manually and had no access to pollinating hummingbirds. 8,Although seed production was not reduced significantly by flower mites, our results suggest that the presence of floral mites can affect pollen transmission, as the amount of nectar available to hummingbirds was reduced drastically. This can directly affect hummingbird foraging patterns and reduce the fitness of the host plants. [source] The effects of plant structure on the spatial and microspatial distribution of a bromeliad-living jumping spider (Salticidae)JOURNAL OF ANIMAL ECOLOGY, Issue 1 2005GUSTAVO Q. ROMERO Summary 1In several regions of South America, the neotropical jumping spider Psecas chapoda inhabits and reproduces strictly on the bromeliad Bromelia balansae. Previous studies reported that this spider is more frequent on bromeliads in grasslands than on those growing in forests, and on larger plants, but only when the bromeliads are without inflorescence. Upon blooming, B. balansae fold their leaves back, thereby changing the plant architecture from a tri-dimensional to a bi-dimensional flattened shape, and our hypothesis is that this alteration affects the spider's habitat-selection decisions. 2In the present study, we examined experimentally the effects of inflorescence, plant size and blockade of the axil of the leaves (spider shelters) of forest bromeliads on the colonization of a bromeliad by P. chapoda. By using sticky traps, we also compared prey availability in grassland and forest. 3Plants with simulated inflorescence were colonized at a lower frequency than those without inflorescence simulation. Grassland bromeliads in which the rosettes were blocked with dry leaves were colonized less frequently than open bromeliads, whereas forest bromeliads from which dry leaves had been removed were not colonized. Spiders generally abandoned bromeliads in which three-quarters of the length of the leaves had been removed, although females with eggsacs remained on these plants. Prey availability (biomass and number) was up to 18 fold higher in the grassland than in the forest. These results suggest that microhabitat structure and prey availability shape the spatial distribution of P. chapoda populations. 4Our findings suggest that Psecas chapoda can evaluate, in fine detail, the physical state of its microhabitat, and this unusual spider,plant association is readily destabilized by changes in the microhabitat (i.e., it is strictly dependent on the size and morphology of the host plant). This study is one of the few to report a strict association between a spider species and its host plant, and also one of the few to examine the effects of habitat and microhabitat structure on the spatial distribution of active hunters on plants. [source] What does the male function hypothesis claim?JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 5 2000Burd Paternal, rather than maternal, fitness consequences of reproductive traits are the lynchpin in many hypotheses about reproductive evolution in hermaphroditic angiosperms. These hypotheses often differ in their predictions, so that supporting or contradictory evidence for one hypothesis may not reflect similarly on another, even though both may be referred to as ,the male function hypothesis'. We provide graphical representations of four male function hypotheses from the recent literature in order to highlight their differences. We offer and explain two recommendations to reduce ambiguity in terminology: (1) male function hypotheses should address the evolution of excess flowers per se, rather than total flower number, which is usually highly plastic in modular organisms with open growth form; and (2) attention must be given to whole plant fitness, rather than fitness per flower or per inflorescence. In empirical studies, we recommend the use of path analysis to dissect the multiple pathways (through both male and female function) by which selection may act on excess flower number. [source] Variation in Floral Sex Allocation and Reproductive Success in Sequentially Flowering Inflorescence of Corydalis remota var. lineariloba (Fumariaceae)JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 3 2009Yan-Fei Zeng Abstract In hermaphroditic plants, female reproductive success often varies among different positions within an inflorescence. However, few studies have evaluated the relative importance of underlying causes such as pollen limitation, resource limitation or architectural effect, and few have compared male allocation. During a 2-year investigation, we found that female reproductive success of an acropetally flowering species, Corydalis remota Fisch. ex Maxim. var. lineariloba Maxim. was significantly lower in the upper late developing flowers when compared with the lower early flowers. Supplementation with outcross pollen did not improve female reproductive success of the upper flowers, while removal of the lower developing fruits significantly increased female reproductive success of the upper flowers in both years, evidencing resource limitation of the upper flowers. Female production in upper flowers was greatly improved by simultaneous pollen supplementation of the upper flowers and removal of the lower fruits, suggesting that, when resources are abundant, pollen may limit the female reproductive success of the upper flowers. The less seed mass in the upper flowers didn't increase in all treatments due to architecture. In the upper flowers, ovule production was significantly lower and the pollen : ovule ratio was significantly higher. These results suggest that male-biased sex allocation in the upper flowers may lead to increased male reproductive success, whereas the lower flowers have higher female reproductive success. [source] Tremacron aurantiacum var. weiningense (Gesneriaceae) var. nov. from Guizhou, ChinaNORDIC JOURNAL OF BOTANY, Issue 2 2010Shun-Zhi He Tremacron aurantiacum var. weiningense (Gesneriaceaea), a new variety of Tremacron aurantiacum found in northwest Guizhou, China, is described and illustrated. This new variety differs from T. aurantiacum K. Y. Pan var. aurantiacum in the following respects: it has appressed pubescence and tomentum on the lower surface of its leaves, inflorescence is 4,8-flowered, 5,10 cymes, peduncles and pedicels are covered with glandular pubescence, the corolla is thin with tube-like upper lips indistinct and cut-like, the stigma is 1, capitate. [source] Teucrium ramaswamii sp. nov. (Lamiaceae) from IndiaNORDIC JOURNAL OF BOTANY, Issue 2 2009M. B. Viswanathan A new species of Lamiaceae, Teucrium ramaswamii M. B. Viswan. & U. Manik. is described from the Kalakkad-Mundanthurai Tiger Reserve (KMTR) in the Agastyamalai hills of the southwestern Ghats in peninsular India. It is allied to T. tomentosum Heyne ex Benth. but differs by stem, leaves and inflorescence being glandular strigose; leaves being deltoid,ovate, crenate,dentate or doubly crenate,dentate at margin, subcoriaceous, sparsely strigose above, densely strigose beneath; bracts being oblong,deltoid, ca 9.4×2.6 mm; calyx with uppermost teeth being lanceolate, ca 2.8×1.9 mm, lateral teeth being broadly triangular, lower teeth being oblong,lanceolate; corolla being glandular strigose outside below lateral lobes and ovary being glandular strigose. Using the IUCN criteria, conservation status of the species is assigned as Critically Endangered based on the field data (2000,2002). Life history studies, population ecology, genome resource banking and wild population management are recommended for conserving this species. [source] Flufenacet herbicide treatment phenocopies the fiddlehead mutant in Arabidopsis thalianaPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2003Christa Lechelt-Kunze Abstract In order to study the mode of action of herbicides we conducted a pilot study analysing phenotype and gene expression of flufenacet- and benfuresate-treated Arabidopsis thaliana (L) Heynhoe plants. Treatments with either herbicide caused phenocopies of the known Arabidopsis mutant fiddlehead, displaying fused organs and the typical fiddlehead-like inflorescence. Herbicide treatments of other plant species, including monocots, also gave rise to analogous organ fusions, indicating the presence of the target in a broad range of plants. Furthermore, many other herbicides with a proposed similar mode of action, eg chloroacetanilides, produced comparable fusion phenotypes in plants. The fiddlehead gene encodes a putative very-long-chain fatty acid elongase (VLCFAE), which corroborates earlier biochemical results pointing to the inhibition of VLCFA synthesis as mode of action of flufenacet. Gene expression profiles of herbicide-treated plants using the first 8247 gene Arabidopsis gene array of Affymetrix provided additional clues in support of inhibition of VLCFA synthesis. We discuss fiddlehead -like elongases as plant specific targets for flufenacet and many other herbicides. Copyright © 2003 Society of Chemical Industry [source] Pattern of Flower and Fruit Production in Stryphnodendron adstringens, an Andromonoecious Legume Tree of Central BrazilPLANT BIOLOGY, Issue 6 2003P. L. Ortiz Abstract: Patterns of flower and fruit production in racemes of Stryphnodendron adstringens, an andromonoecious Brazilian savanna tree species, were studied in two natural areas near Uberlândia-MG. Racemes were divided in three parts: apex, centre, and base. Number of flowers, gender, and nectar and pollen production were analyzed for each section. Frequency of visitors to each part of the inflorescence was also quantified. Hand self- and cross-pollinations were performed in complete racemes and fruit set used to determine breeding system. The racemes produced a mean of 329 flowers, more densely packed in the central portion. Hermaphrodite and male flowers occur along the inflorescence but hermaphrodite flowers are more common in the centre. Fruit set was markedly low but does not seem to be limited by pollination service, since free open-pollinated racemes and hand cross-pollinated ones do not differ in fruit production rates. Fruits resulted mostly from cross-pollinated flowers and fruit production was biased to the central portion of the raceme. Nectar yield was higher in the central portion of the raceme and visitors arrived more commonly on this portion of the inflorescence. However, most flowers did not produce nectar. The pattern of fruit production seems to be a consequence of the hermaphrodite flower distribution in the raceme and it is not constrained by pollen flow or flower opening sequence. [source] Variation in fruit- and seed set among and within inflorescences of Melampyrum roseum var. japonicum (Scrophulariaceae)PLANT SPECIES BIOLOGY, Issue 1 2002Kayako Hiei Abstract Variations in fruit set and seed set among and within inflorescences of the annual herb, Melampyrum roseum var. japonicum, were studied. Under natural conditions, although the mean fruit set was slightly different among inflorescences, the mean seedset was not significantly different among inflorescences within the plants. In constrast, within the inflorescences, the flowers located at a lower position of the inflorescence and which opened earlier showed higher fruit set than those at a higher position and which opened later. However, the seed set of matured capsules were not significantly different from each other, regardless of the position of flowers within the inflorescences. Patterns of the fruit- and seed set under open pollination indicated that variation in seed reproduction of M. roseum is due to variation in fruit production. The results of clipping experiments of flowers revealed that there was no functional limitation in seed production among flowers located at various positions within the inflorescence. It seemed that the variation in the fruit set within the inflorescences of M. roseum was not attributable to ,architectural effects'. Reduction of the number of flowers within the inflorescences resulted in an increase of fruit set and seed weight, indicating that the flowers in an inflorescence compete for resources. This phenomenon supports the ,resource competition hypothesis', and variation in fruit set within the inflorescence is attributable to competition among flowers within the inflorescence for limited resources. Consequently, it was concluded that, under natural conditions, the early blooming flowers located at lower positions of the inflorescences obtain more resources and produce more fruits than the late blooming flowers located at higher positions in M. roseum. [source] A morphological study of the development of the second inflorescences in strawberry (Fragaria×ananassa Duch.)ANNALS OF APPLIED BIOLOGY, Issue 4 2005T KUROKURA Summary To clarify the timing of the differentiation of the first and second inflorescences in strawberry (Fragaria × ananassa Duch.), morphological changes on shoot apices during short day and low night temperature treatments were observed by scanning electron microscopy (SEM) and optical microscopy. Axillary buds just below the first inflorescence (axillary bud 1) became visible when sepal primordia of the primary flower were differentiated. By this time, other axillary buds had already developed. Axillary bud 1 developed four leaf primordia, and then a differentiated inflorescence at its summit. The phase transition of shoot apices from the vegetative to the reproductive phase may therefore trigger the differentiation of axillary bud 1 which is destined to develop into extension crowns. [source] Habitat protection, cattle grazing and density-dependent reproduction in a desert treeAUSTRAL ECOLOGY, Issue 8 2009VALERIA ASCHERO Abstract Anthropogenic activities usually trigger changes in the population density of plants. Thus, land management practices can influence density-dependent demographic parameters and species interactions. We investigated plant-pollinator interactions and reproduction in Prosopis flexuosa, the largest tree species in the Central Monte desert of Argentina, an important economic and cultural resource for humans and a functionally prominent species. We hypothesized that reproductive output of P. flexuosa would be limited at low densities, and that exclusion of catle grazing would enhance population density and consequently interaction frequency with pollinators and reproductive success. The study was conducted in and around Ñacuñán Biosphere Reserve (Mendoza, Argentina), where cattle grazing has been excluded for over 35 years. Working in five pairs of protected and cattle grazed 1-ha plots, we recorded density of adult trees, pollinator visitation frequency to inflorescences and seeds per inflorescence in focal trees. Adult tree density was higher in protected plots than in cattle grazed plots. Density of reproductive trees was positively correlated with seed production, suggesting positive density dependence for reproduction (Allee effect). Pollinator visitation to inflorescences and seed production was higher in protected plots compared with plots under cattle grazing. Suppression of anthropogenic degradation has resulted in higher adult tree density in protected plots, indirectly higher pollinator visitation to inflorescences and higher reproductive success of trees. Increased frequency of plant-pollinator interactions and tree reproduction suggest success of management practices aimed at protecting P. flexuosa woodlands. [source] Causes of spatial patterns of fruit set in waratah: Temporal vs. spatial interactions between flowers on an inflorescenceAUSTRAL ECOLOGY, Issue 1 2009ROBERT J. WHELAN Abstract Spatial patterns of fruit set within inflorescences may be controlled by pollination, nutrient allocation, or inflorescence architecture. Generally, flowers that have spatial and/or temporal precedence are more likely to set fruits. We sought to separate these factors by comparing patterns of fruit set on inflorescences of two species of Telopea (Proteaceae); one that flowers from the tip to the base of the rachis, the other from base to tip. In both species, most fruits were set at the top of the inflorescence (the last flowers to open for T. speciosissima) and this was extreme for T. mongaensis, where the top flowers open first. Fruit set was not generally limited by inadequate pollination for either T. mongaensis or T. speciosissima, as hand pollinations did not increase fruit set and many abscised flowers contained pollen tubes. In T. speciosissima, we tested whether removal of developing topmost fruits would ,release' those that had initiated but not yet aborted lower down. There was no significant effect. Plant hormones can increase the degree to which a developing fruit is a sink for nutrients, so we applied cytokinin to the developing lower fruits on some inflorescences. There was no significant effect of the hormone treatment. We conclude that temporal precedence may contribute to the skewed pattern of fruit set in T. mongaensis, because there was an extreme concentration of fruit set on the distal part of the inflorescences, but it cannot explain this pattern of fruit set in T. speciosissima, where the distal flowers are the last to open. Some other process must therefore constrain fruit set to the topmost flowers in an inflorescence. While cytokinin application had no significant effect, the power of this experiment was low and we consider that the hypothesis of hormonal control is worth further exploration. [source] Classification of reproductive performance of ten winegrape varietiesAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2010P.R. DRY Abstract Background and Aims:, Flowering and fruitset are principal determinants of grapevine yield. Poor fruitset is said to limit the yield of many varieties in most regions in Australia; however, there is a lack of knowledge of the reproductive performance of most varieties under Australian conditions. Methods and Results:, The reproductive performance of Vitis vinifera winegrape varieties , Cabernet Sauvignon, Chardonnay, Merlot, Nebbiolo, Pinot Noir, Sangiovese, Sauvignon Blanc, Shiraz, Tempranillo, and Zinfandel , was studied in four consecutive growing seasons (commencing in 2004/05) across a range of climatic regions from cool (Adelaide Hills) to warm (Adelaide Plains). Measures of reproductive performance included flower number per inflorescence, fruitset (%), berry number per bunch, coulure index (CI), and millerandage index (MI). Principal component analysis and agglomerative hierarchical classification were used to group the varieties into three classes of reproductive performance. Conclusions:, Certain varieties have a reputation of having ,poor fruitset' that has been inferred from relatively low berry number per bunch; however, for some of these varieties, it is ,low flower number per inflorescence' rather than ,poor fruitset' that is the cause of low berry number. Significance of the Study:, An improved understanding of the reproductive performance of winegrape varieties has been achieved. [source] From bud to berry, with special reference to inflorescence and bunch morphology in Vitis vinifera L.AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2 2000PETER MAY Abstract A brief review of the reproductive system of the grapevine is presented. Phases discussed include floral induction and initiation during early spring, inflorescence primordium growth during summer to dormancy, flower formation at budburst in the subsequent growing season, and finally flowering and berry development. Difficulties in clearly defining and describing some of these developmental stages will be outlined, especially the complex bud system, the morphology of buds at budburst, and the course of flowering. The course of floral development during dormancy and at the time of budburst requires further attention, especially the reported effect that low temperature at budburst leads to increased numbers of flowers. Also, the recent finding that ,intercarpellar' floral organs can be induced by applying auxin is of particular interest and will be described. Case studies from Burgundy vineyards with Chardonnay, Pinot Noir and Gamay ovaries and berries will be included. A detailed analysis of what constitutes a grape bunch will be presented from observations of Chardonnay inflorescences and bunches collected at random after set and at harvest in two seasons from spur-pruned, cane-pruned and hedged vines growing on two sites varying in climate and productivity (Adelaide Hills and Southern Vales of South Australia). This analysis covered variability in numbers of branches and flowers and in per cent berry set, as well as relationships between branch numbers and flower numbers. Relationships between flower numbers and per cent set, per cent set and berry size along the inflorescence, and berry size and seed complement are outlined. Likely implications of inter-bunch and intra-bunch variability for bunch compactness, berry composition and yield components are discussed. [source] Mining plant diversity: Gerbera as a model system for plant developmental and biosynthetic researchBIOESSAYS, Issue 7 2006Teemu H. Teeri Gerbera hybrida is a member of the large sunflower family (Asteraceae). Typical of Asteraceae, Gerbera bears different types of flowers in its inflorescence. The showy marginal flowers comprise elongate, ligulate corollas that are female, whereas the central and inconspicuous disc flowers are complete, with both male and female organs. As such, Gerbera offers great potential for comparative developmental research within a single genotype. Moreover, different Gerbera varieties show an impressive spectrum of color patterns, directly displaying responses to developmental cues at all important morphological levels (flower type, flower organ and within organs). Further, Gerbera harbors an arsenal of Asteraceae-type secondary metabolites, not present in other model plants. With powerful reverse genetics methods, a large collection of EST sequences and a new cDNA microarray, Gerbera has become a model plant of the sunflower family. BioEssays 28: 756,767, 2006. © 2006 Wiley Periodicals, Inc. [source] Plasticity, its cost, and phenotypic selection under water and nutrient stress in two annual grassesBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2009SERGEI VOLIS A comparative approach can prove to be a useful tool for studying phenotypic plasticity, if applied to specific traits involved in adaptation to particular environment in more than one species across co-located populations. The present study tested whether two annual grasses, Hordeum spontaneum and Avena sterilis, belonging to the same guild, having similar stature, seed dispersal mechanism, breeding system, and genetic variation, and sampled in exactly the same environmentally specific locations, differed with respect to: (1) plasticity in traits involved in adaptation, namely the onset of reproduction and maternal investment involving the number of inflorescences, spikelets per inflorescence, the weight of individual spikelets, and abortion rate; (2) the cost of this plasticity, and (3) the pattern of phenotypic selection on the above traits. The two species exhibited highly differing amounts of phenotypic plasticity in the onset of flowering and several reproductive traits (number of inflorescences, spikelets per inflorescence, abortion rate), but no plasticity costs in any experimental environment. The two species demonstrated a decreasing similarity in the regulation of reproduction in four experimental environments: benign, water, nutrients and water × nutrient deficient. Correlational selection appears to contribute, although not solely, to the observed species differences with respect to the regulation of reproduction. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 581,593. [source] Different Stimuli Reduce Attraction to Pollinators in Male and Female Figs in the Dioecious Fig Ficus hispidaBIOTROPICA, Issue 6 2009Hao-Yuan Hu ABSTRACT Fig trees (Ficus) and their obligate pollinating wasps (Hymenoptera, Chalcidoidea, Agaonidae) are a classic example of a coevolved mutualism. Pollinating wasps are attracted to figs only when figs are receptive. It has been shown that figs will lose their attraction to pollinators sooner in monoecious and male dioecious figs when multiple pollinators have entered the enclosed inflorescence. However, little is known about the nature of the stimulus inducing the loss of attraction. By conducting experiments on the functionally dioecious fig, Ficus hispida, we show that (1) different stimuli induce the loss of attraction in each sex, pollination in female figs, and oviposition in male figs; and (2) foundress number affects the loss of attraction in both sexes only when the prerequisites (i.e., pollination in female figs and oviposition in male figs) have been satisfied. In general, the more foundresses that enter, the earlier the fig will lose its receptivity. We argue that the stimuli in male and female figs are adaptations to the fulfillment of its respective reproduction. [source] | |||||||||||||||||||||||||||||||||||||