Influence of floral visitation on nectar-sugar composition and nectary surface changes in Eucalyptus

Davis, Arthur R.

doi:10.1051/apido:19970104

Cited by 50 publications

(45 citation statements)

References 28 publications

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“…It should be noted that in the European Fritillary, all nectar sugar constituents were resorbed to a similar degree, because the proportion of individual sugars at the final stage of anthesis remained almost unchanged. This result compares well with that obtained for Eucalyptus (Davis 1997).…”

Section: Nectar Secretion and Resorptionsupporting

confidence: 91%

Secretion and composition of nectar and the structure of perigonal nectaries in Fritillaria meleagris L. (Liliaceae)

2012

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The structure of perigonal nectaries, nectar production and carbohydrate composition were compared at various stages in the lifespan of the flower of Fritillaria meleagris L. The six nectaries each occupied a groove that is located 2-4 mm above the tepal base. The average nectary measured 11.0 mm long and 1.0-1.2 mm wide. The structure of nectaries situated on both inner and outer tepal whorls was identical, and at anthesis they were equally accessible to potential pollinators. However, secretion from nectaries associated with inner tepals tended to exceed that produced by nectaries located on the outer tepals. On average, regardless of flower stage, one flower secreted 10.87 ± 12.98 mg of nectar (mean and SD; N = 182). The nectar concentration ranged between 3 and 75%, with average concentration of sugars exceeding 50%. Both nectar production and concentration were dependent on the stage of anthesis, with the highest scores being recorded during full anthesis (21.75 ± 16.08 mg; 70.5%, mass and concentration, respectively) and the lowest at the end of anthesis (1.32 ± 2.69 mg; 16.9%, mass and concentration, respectively). A decline in both mass of nectar secreted and nectar concentration during the final stage of anthesis indicates nectar resorption. Nectar was composed of sucrose, glucose and fructose in approx. equal quantities, and its composition did not change significantly during subsequent stages of flowering. The nectaries comprised a single-layered secretory epidermis and several layers of subepidermal parenchyma. The nectariferous cells did not accumulate starch during any of the investigated stages. The nectary was supplied with one large and several smaller vascular bundles comprising xylem and phloem. Transport of assimilates and nectar secretion by protoplasts of secretory cells (and probably also nectar resorption) were facilitated by cell wall ingrowths present on the tangential walls of epidermal cells and subepidermal parenchyma. Epidermal cells lacked stomata. Nectar passed across the cell wall and through the cuticle which was clearly perforated with pores.

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Section: Nectar Secretion and Resorptionsupporting

confidence: 91%

Secretion and composition of nectar and the structure of perigonal nectaries in Fritillaria meleagris L. (Liliaceae)

2012

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“…Nectar sugar composition remains constant in the long-lived flowers of three species of Eucalyptus, in spite of continual exposure to visitors (Davis, 1997). In Combretum fruticosum (Combretaceae), there is no decrease in sucrose with flower age (Bernardello et al, 1994).…”

Section: Constancy Of Sugar Composition Within Speciesmentioning

confidence: 99%

Nectar chemistry

Nicolson

Thornburg

2007

Nectaries and Nectar

398

513

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“…The Eucalyptus genus overall outcrossing-rate is estimated to be up to 73% (Moran 1992). Typical of the Myrtaceae, E. grandis nectar preferentially attracts Apis mellifera (Davis 1997). In some countries, A. mellifera has been introduced into Eucalyptus seed-production areas to enhance seed production (Moncur et al 1995).…”

Section: Introductionmentioning

confidence: 99%

Gene flow estimation with microsatellites in a Malagasy seed orchard of Eucalyptus grandis

Chaix

Gerber²,

Razafimaharo³

et al. 2003

Theor Appl Genet

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Eucalyptus grandis has a mixed-mating reproductive system. Malagasy Eucalyptus seed orchards were established 15 years ago with two aims both based on panmixia: open-pollinated seed production and genetic improvement. The panmixia hypothesis has never been confirmed in the seed orchard. From a seedling seedorchard stand comprising 349 trees and using data obtained with six selected microsatellite markers, paternity analysis was performed for 724 offspring collected on 30 adult trees. Paternity assignment, based on exclusion procedures and likelihood-ratio method, was achieved with high accuracy; the exclusion probability value was 0.997. The outcrossing rate was very high (96.7%). More than 50% of potential male trees (199 out of 349) in the seed orchard contributed to pollination for 440 offspring of 30 progenies (8.6% of the basic population). The pollination rate from outside the seed orchard was high (39.2%), but might be due to the small size of this seed orchard. This study showed that "panmixia-like pollination" can be assumed.

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Influence of floral visitation on nectar-sugar composition and nectary surface changes in Eucalyptus

Cited by 50 publications

References 28 publications

Secretion and composition of nectar and the structure of perigonal nectaries in Fritillaria meleagris L. (Liliaceae)

Secretion and composition of nectar and the structure of perigonal nectaries in Fritillaria meleagris L. (Liliaceae)

Nectar chemistry

Gene flow estimation with microsatellites in a Malagasy seed orchard of Eucalyptus grandis

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