Nectar secretion strategy in three Japanese species: changes in nectar volume and sugar concentration dependent on flower age and flowering order

Botany ◽  
2008 ◽  
Vol 86 (4) ◽  
pp. 337-345 ◽  
Author(s):  
Shinya Kato ◽  
Satoki Sakai
Keyword(s):  
Reproductive Success ◽  
Early Flowering ◽  
Sugar Concentration ◽  
Nectar Secretion ◽  
Floral Nectar ◽  
Japanese Species ◽  
Nectar Volume ◽  
Flower Age ◽  
Nectar Sugar ◽  
The Mean

We explored how changes in nectar volume and nectar sugar concentration depend on flower age and flowering order in Gentiana triflora Pallas var. japonica (Kusnez.) Hara, Lobelia sessilifolia Lamb., and Hemerocallis middendorffii Trautv. et Mey. var. esculenta (Koidz.) Ohwi. In G. triflora var. japonica and H. middendorffii var. esculenta, change in nectar volume was small, whereas larger changes in nectar sugar concentration occurred depending on flower age. In L. sessilifolia, both the mean nectar volume and nectar sugar concentration clearly decreased with flower age. In all species, the mean nectar volume of the early-flowering group per plant was high. In terms of the change in sex allocation, the investment in male and female organs of the early-flowering group was high in G. triflora var. japonica and L. sessilifolia. We suggest that plants of G. triflora var. japonica and H. middendorffii var. esculenta secrete floral nectar for up to several days to sustain nectar volume to keep attracting pollinators while simultaneously reducing resource usage. Greater nectar secretion in the early-flowering group, in which flowers have more pollen and ovules, may contribute to greater reproductive success and may be effective for pollinators in learning the location of the plants and flowers. In addition, learning by pollinators should result in increased reproductive success of the later blooming flowers.

Nectar secretion pattern and removal effects in three species of Solanaceae

1993 ◽  
Vol 71 (10) ◽  
pp. 1394-1398 ◽  
Author(s):  
Leonardo Galetto ◽  
Luis Bernardello
Keyword(s):  
Sugar Production ◽  
Nectar Secretion ◽  
Nicotiana Glauca ◽  
Time Intervals ◽  
Nectar Production ◽  
Nectar Volume ◽  
Significant Difference ◽  
Flower Age ◽  
Nicotiana Longiflora ◽  
Nectar Sugar

Nectar secretion pattern and effects of nectar removal were compared in three Argentinean Solanaceae: Nicotiana glauca, which is hummingbird pollinated, and Nicotiana longiflora and Petunia axillaris, which are sphinx moth pollinated. Nectar volume, concentration, and sugar production were measured at different time intervals according to the species' flower life span. Nectar volume and total sugar production increased as a function of flower age in both species of Nicotiana analyzed; however, these parameters were quite stable in P. axillaris. This species produced less nectar and nectar sugar than the other two. When all sets with nectar removal were compared with the controls, significant differences were found in nectar volume and quantity of nectar sugar in N. longiflora, and in sugar concentration in P. axillaris. In the latter, the observed difference did not affect the total amount of sugar secreted. Nicotiana glauca did not show any significant difference in the parameters analyzed. Total nectar production was inhibited by periodic removal in N. longiflora, while in N. glauca and P. axillaris it was unaffected. Key words: nectar secretion pattern, nectar removal, Nicotiana, Petunia, Solanaceae.

scholarly journals Salvage of floral resources through re-absorption before flower abscission

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Graham H. Pyke ◽  
Zong-Xin Ren ◽  
Judith Trunschke ◽  
Klaus Lunau ◽  
Hong Wang
Keyword(s):  
Floral Resources ◽  
Floral Nectar ◽  
Nectar Volume ◽  
Flower Colours ◽  
Nectar Concentration ◽  
Nectar Sugar ◽  
Biochemical Mechanisms ◽  
Floral Resource ◽  
Almost All

Abstract Plants invest floral resources, including nectar and pigment, with likely consequent reproductive costs. We hypothesized that plants, whose flowers abscise with age, reabsorb nectar and pigment before abscission. This was tested with flowers of Rhododendron decorum, which has large, conspicuous white flowers that increasingly abscise corollas as flowers age. As this species is pollinated by bees, we also hypothesized that nectar concentration would be relatively high (i.e., > 30% wt/vol) and petals would contain UV-absorbing pigment. Floral nectar volume and concentration were sampled on successive days until abscission (up to ten days old, peak at five days) and for sub-sample of four-day-old flowers. Flowers just abscised were similarly sampled. Flower colours were measured using a modified camera, with recordings of spectral reflectance for abscised and open non-abscised flowers. Pigment content was summed values of red, green, blue channels of false color photos. As expected, flowers reabsorbed almost all nectar before abscission, separately reabsorbing nectar-sugar and nectar-water, and petals contained UV-absorbing pigment. However, flowers did not reabsorb pigment and nectar-concentration was < 30% wt/vol. That flowers reabsorb nectar, not pigment, remains unexplained, though possibly pigment reabsorption is uneconomical. Understanding floral resource reabsorption therefore requires determination of biochemical mechanisms, plus costs/benefits for individual plants.

Nectar collected with microcapillary tubes is less concentrated than total nectar in flowers with small nectar volumes

2011 ◽  
Vol 59 (6) ◽  
pp. 593 ◽  
Author(s):  
Sophie Petit ◽  
Nadia Rubbo ◽  
Russell Schumann
Keyword(s):  
Regression Analysis ◽  
Large Volume ◽  
Standing Crop ◽  
Total Sugar ◽  
Sugar Concentration ◽  
Nectar Volume ◽  
Nectar Sugar ◽  
Total Sugar Concentration ◽  
Pollination Systems ◽  
Feeding Behaviours

Previous research indicated that microcapillary tubes greatly underestimated sugar present in flowers with low nectar volumes, but it was unclear whether tubes missed liquid nectar or whether sugar concentration in nectar they collected did not represent total sugar concentration in a flower. We determined the suitability of microcapillary tubes to estimate the energetic value of Acrotriche patula R.Br. (Ericaceae) nectar from total sugar mass. We collected a standing crop of nectar from individual flowers with microcapillary tubes and subsequently washed the flowers to recover putatively any residual sucrose, glucose, and fructose. We assessed microcapillary nectar volume as a predictor for total sugar mass in a flower by regression analysis, identified the percentage of sugar missed by microcapillary tubes, and compared sugar ratios between microcapillary samples and total nectar. Nectar volume collected with microcapillary tubes cannot be used to predict total nectar sugar contents in a flower. Microcapillary tubes missed 71% of the floral sugar on average, but not a large volume, indicating that sugar is not evenly distributed in a flower’s nectar. Proportions of different sugars did not differ significantly between microcapillary samples and total samples. Animals with different tongue morphologies and feeding behaviours may obtain different energetic rewards from the same flower with low nectar volume. Variation in a flower’s nectar at one point in time is likely to favour the generalisation of pollination systems.

Rewards 2: The Biology of Nectar

2011 ◽  
Author(s):  
Pat Willmer
Keyword(s):  
Chemical Composition ◽  
Nectar Secretion ◽  
Water Reward ◽  
Floral Nectar ◽  
Nectar Production ◽  
Nectar Volume ◽  
Floral Reward ◽  
Nectar Concentration

This chapter examines the biology of nectar, the main secondary floral reward in an evolutionary sense. As a commodity, nectar is easy for plants to produce and easy for animals to handle; its sugars are simple to metabolize and thus to use as a readily available fuel for an animal’s activities. Nectar is a crucial factor in determining the interactions of flowers and their visitors. The chapter first provides an overview of how floral nectar is produced in a nectary before discussing nectar secretion, the chemical composition of nectar, and nectar volume. It then considers nectar concentration and viscosity, nectar as a sugar and energy reward, and nectar as a water reward. It also explores daily, seasonal, and phylogenetic patterns of nectar production, how flowers control their nectar and their pollinators, and problems in measuring and quantifying nectar. The chapter concludes with an analysis of the costs of nectar gathering.

Nectar Sugars in Proteaceae: Patterns and Processes

1998 ◽  
Vol 46 (4) ◽  
pp. 489 ◽  
Author(s):  
Susan W. Nicolson ◽  
Ben-Erik Van Wyk
Keyword(s):  
Diagnostic Value ◽  
Floral Nectar ◽  
Ecological Processes ◽  
Generic Level ◽  
Plant Phylogeny ◽  
Physiological Processes ◽  
Pentose Sugar ◽  
Flower Age ◽  
Nectar Sugar ◽  
Patterns And Processes

The nectar sugar composition is presented for 147 species from 16 genera of South African and Australian Proteaceae. Patterns associated with flower age, different plants and populations, plant phylogeny and pollination have been examined. In addition to the usual three nectar sugars (sucrose, fructose and glucose), the nectar of Protea and Faurea contains the pentose sugar xylose at concentrations of up to 39% of total sugar. Xylose has not previously been reported from floral nectar and is absent from the nectar of Adenanthos, Banksia, Brabejum, Dryandra, Grevillea, Hakea, Lambertia, Leucospermum, Macadamia, Mimetes, Orothamnus, Paranomus, Stenocarpus and Telopea. Most genera and species have hexose-dominant nectar, but within the large genera Banksia, Grevillea, Leucospermum and Protea some of the seemingly more derived species have sucrose-dominant nectar. This interesting dichotomy of low versus high sucrose is of diagnostic value at the species level and indicative of phylogenetic relationships within the larger genera. At the generic level, the presence of xylose is a convincing synapomorphy for Protea and Faurea. Studies of physiological processes (e.g. enzyme activities) and ecological processes (e.g. pollination) may help to explain some of the conservative and taxonomically interesting nectar sugar patterns.

scholarly journals Floral Phenology, Nectar Secretion Dynamics, and Honey Production Potential, of Two Lavender Species (Lavandula Dentata, and L. Pubescens ) in Southwestern Saudi Arabia

2015 ◽  
Vol 59 (2) ◽  
pp. 135-144 ◽  
Author(s):  
Adgaba Nuru ◽  
Ahmad A. Al-Ghamdi ◽  
Yilma T. Tena ◽  
Awraris G. Shenkut ◽  
Mohammad J. Ansari ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Early Morning ◽  
Nectar Secretion ◽  
Flowering Pattern ◽  
Honey Production ◽  
Species Overlap ◽  
Floral Phenology ◽  
Efficient Resource ◽  
Nectar Sugar ◽  
The Mean

AbstractThe aim of the current study was to determine the floral phenology, nectar secretion dynamics, and honey production potentials of two naturally growing lavender species (L. dentata and L. pubescens), in southwestern Saudi Arabia. In both species, flowering is continuous. This means that, when open flowers on a spike are shaded, new flowers emerge. Such a flowering pattern might be advantageous to the plant to minimise competition for pollinators and promote efficient resource allocation. The flowering periods of the two species overlap. Both species secreted increasing amounts of nectar from early morning to late afternoon. The mean maximum volumes of accumulated nectar from bagged flowers occurred at 15:00 for L. pubescens (0.50 ± 0.24 μL/flower) and at 18:00 for L. dentata (0.68 ± 0.19 μL/flower). The volume of the nectar that became available between two successive measurements (three-h intervals) varied from 0.04 μL/flower to 0.28 μL/flower for L. pubescens and from 0.04 μL/flower to 0.35 μL/ flower for L. dentata, This variation reflects the differences in the dynamics of nectar secretion by these species, and indicates the size of the nectar that may be available for flower visitors at given time intervals. The distribution of nectar secretions appears to be an adaptation of the species to reward pollinators for longer duration. Based on the mean amount of nectar sugar secreted by the plants, the honey production potentials of the species are estimated to be 4973.34 mg and 3463.41 mg honey/plant for L. dentata and L. pubescens, respectively.

scholarly journals Biology of flowering and nectar production in the flowers of the beauty bush (Kolkwitzia amabilis Graebn.)

2012 ◽  
Vol 65 (4) ◽  
pp. 15-20
Author(s):  
Marta Dmitruk
Keyword(s):  
Life Span ◽  
Pollen Grains ◽  
Sugar Concentration ◽  
Bud Break ◽  
Nectar Production ◽  
The Third ◽  
Nectar Sugar ◽  
The Mean

Nectar production and the morphology of the nectary and pollen grains of <em>Kolwitzia amabilis </em>Graebn. were studied during the period 2008–2009 and in 2011. The blooming of beauty bush flowers started in the third decade of May and ended in the middle of June; flowering lasted 22–23 days. The flower life span was 4–5 days. Nectar production began at the bud break stage. The tube of the corolla in beauty bush flowers forms a spur inside which the nectary is located. The secretory surface of the nectary consists of two layers of glandular epidermal outgrowths: unicellular trichomes, with their length ranging 54.6 μm – 70.2 μm, and papillae with a length of 13.0 μm – 20.6 μm. The mean weight of nectar per 10 flowers, determined for the three years of the study, was 8.6 mg, with a sugar concentration of 50.8%. The weight of nectar sugar was on average 4.4 mg. In terms of the size, beauty bush pollen grains are classified as medium-sized. These are tricolporate grains.

scholarly journals Influence of microclimatic conditions on nectar exudation in Glechoma hirsuta  W. K

2005 ◽  
Vol 57 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Marina Macukanovic-Jocic ◽  
Lola Djurdjevic
Keyword(s):  
Secretion Rate ◽  
Sugar Concentration ◽  
Test Plot ◽  
Habitat Conditions ◽  
Nectar Secretion ◽  
Atmospheric Humidity ◽  
Nectar Production ◽  
Nectar Volume ◽  
Close Relationship ◽  
Microclimatic Conditions

The nectar production of Glechoma hirsuta W. K. grown under different microclimatic habitat conditions was evaluated by determining the total daily nectar quantity per flower, diurnal dynamics of nectar secretion, the nectar secretion rate, and sugar concentration. Comparative analyses of nectar production in Glechoma hirsuta grown in a forest and on a test plot confirmed that this process varied as a function of microclimatic parameters (atmospheric humidity and air temperature), but did not reveal a close relationship between these parameters and sugar concentration in nectar. More intensive nectar secretion, with a decreasing tendency during the day, and higher total daily nectar volume per plant (1.603 ml/flower) were measured in the forest habitat. Diurnal variation in nectar production with two secretion peaks was found at both localities, and the secretion patterns were rather similar. Regarding the nectar secretion rate, G. hirsuta is a slow producer secreting less than 0.07 ml/h.

scholarly journals Canopy Position, Defoliation, and Girdling Influence Apple Nectar Production

HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 531-532 ◽  
Author(s):  
Richard J. Campbell ◽  
Richard D. Fell ◽  
Richard P. Marini
Keyword(s):  
Sugar Concentration ◽  
Nectar Production ◽  
Nectar Volume ◽  
Canopy Position ◽  
Nectar Sugar

Flowering spurs located at interior and exterior canopy positions of `Stay-man' and `Delicious' apple (Malus domestics Borkh.) trees were girdled and/or defoliated to determine the influence on nectar production and composition. Nectar volume was less at exterior than interior canopy positions for `Delicious', but not for `Stayman'. Girdling suppressed nectar production by 92% and reduced the sugar concentration of the remaining nectar. Defoliation of nongirdled spurs had no effect on nectar sugar concentration, but defoliation of girdled spurs reduced nectar sugar concentration by 24%. Relative percentages of sucrose, glucose, and fructose, and the sucrose: hexose ratio were unaffected by any treatment. Nectar production of nongirdled spurs did not depend on the presence of spur leaves.

scholarly journals Nectar secretion and pollen production in Hyacinthus orientalis ‘Sky Jacket’ (Asparagaceae)

2019 ◽  
Vol 72 (4) ◽  
Author(s):  
Małgorzata Bożek
Keyword(s):  
Apis Mellifera ◽  
Early Spring ◽  
Sugar Concentration ◽  
Pollen Production ◽  
Nectar Secretion ◽  
Floral Reward ◽  
Se Poland ◽  
Hyacinthus Orientalis ◽  
Nectar Sugar ◽  
Flower Position

Flowering, nectar secretion, and pollen production in <em>Hyacinthus orientalis</em> ‘Sky Jacket’ (Asparagaceae) were studied between 2013 and 2015 in Lublin, SE Poland (51°16' N, 22°30' E). The flowering was weather-dependent. It started at the beginning of April or at the end of the month and lasted 14–24 days. The mass of nectar, sugar concentration in the nectar, nectar sugar mass, anther size, and pollen mass in flowers all depended on the flower position in the inflorescence and differed significantly between the years of study. The greatest mass of sugars and pollen was recorded in low-positioned flowers. On average, <em>H. orientalis</em> ‘Sky Jacket’ produced 1.63 mg of sugars and 3.51 mg of pollen per flower. The floral reward was attractive for <em>Apis mellifera</em> and <em>Bombus</em> spp., which indicate that the species should be propagated not only for its decorative value but also for supporting pollinators in early spring.

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