Sexual Dimorphism and between-Year Variation in Flowering, Fruit Set and Pollinator Behaviour in a Boreal Willow

Oikos ◽  
1988 ◽  
Vol 53 (1) ◽  
pp. 58 ◽  
Author(s):  
Thomas Elmqvist ◽  
Jon Ågren ◽  
Anders Tunlid ◽  
Jon Agren
Keyword(s):  
Sexual Dimorphism ◽  
Fruit Set ◽  
Pollinator Behaviour

scholarly journals A comparative study on the reproductive success of two rewarding Habenaria species (Orchidaceae) occurring in roadside verge habitats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wenliu Zhang ◽  
Jiangyun Gao
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Plant Density ◽  
Flowering Plant ◽  
Floral Display ◽  
Pollinator Behaviour ◽  
Factors Affecting ◽  
Nectar Sugar ◽  
Viable Seeds ◽  
Viable Embryo

Abstract Background Most orchid species have been shown to be severely pollination limited, and the factors affecting reproductive success have been widely studied. However, the factors determining the reproductive success vary from species to species. Habenaria species typically produce nectar but exhibit variable fruit set and reproductive success among species. Here, we investigated the influence of the flowering plant density, inflorescence size, breeding system, and pollinator behaviour on the reproductive success of two rewarding Habenaria species. Results Our observations indicated that Habenaria limprichtii and H. petelotii co-occur in roadside verge habitats and present overlapping flowering periods. Both species were pollination limited, although H. limprichtii produced more fruits than H. petelotii under natural conditions during the 3-year investigation. H. petelotii individuals formed distinct patches along roadsides, while nearly all H. limprichtii individuals clustered together. The bigger floral display and higher nectar sugar concentration in H. limprichtii resulted in increased attraction and visits from pollinators. Three species of effective moths pollinated for H. limprichtii, while Thinopteryx delectans (Geometridae) was the exclusive pollinator of H. petelotii. The percentage of viable seeds was significantly lower for hand geitonogamy than for hand cross-pollination in both species. However, H. limprichtii may often be geitonogamously pollinated based on the behaviours of the pollinators and viable embryo assessment. Conclusions In anthropogenic interference habitats, the behaviours and abundance of pollinators influence the fruit set of the two studied species. The different pollinator assemblages in H. limprichtii can alleviate pollinator specificity and ensure reproductive success, whereas the more viable embryos of natural fruit seeds in H. petelotii suggested reducing geitonogamy by pollinators in the field. Our results indicate that a quantity-quality trade-off must occur between species with different breeding strategies so that they can fully exploit the existing given resources.

scholarly journals Temporal dynamics of sexual dimorphism in a dioecious species

2020 ◽  
Vol 126 (3) ◽  
pp. 471-480
Author(s):  
L Moquet ◽  
L Lateur ◽  
A-L Jacquemart ◽  
I De Cauwer ◽  
M Dufay
Keyword(s):  
Sexual Dimorphism ◽  
Plant Species ◽  
Temporal Dynamics ◽  
Flower Size ◽  
Flowering Plant ◽  
Floral Traits ◽  
Flower Number ◽  
Pollinator Behaviour ◽  
Flower Production ◽  
Flowering Season

Abstract Background and Aims Sexual dimorphism for floral traits is common in dioecious plant species. Beyond its significance for understanding how selection acts on plant traits through male vs. female reproductive function, sexual dimorphism has also been proposed as a possible risky characteristic for insect-pollinated plants, as it could drive pollinators to forage mostly on male plants. However, even though most flowering plant species spread their flowering across several weeks or months, the temporal variation of floral phenotypes and sexual dimorphism have rarely been investigated. Methods We performed a survey of male and female plants from the dioecious generalist-pollinated Silene dioica (Caryophyllaceae) in a common garden experiment, over two consecutive flowering seasons. Flower number and floral size were measured each week, as well as pollen quantity and viability in male plants. Key Results Sexual dimorphism was found for all investigated floral traits, with males showing an overall higher investment in flower production and flower size. Males and females showed a similar temporal decline in flower size. The temporal dynamics of daily flower number differed between sexes, with males showing a peak in the middle of their flowering season, whereas flower production by females was quite stable over time. At the scale of the experimental population, both individual and floral sex ratios appeared to vary across the flowering season. Moreover, because the onset of flowering varied among plants, the magnitude of sexual dimorphism in floral size also fluctuated strongly through time. Conclusions Capturing male/female differences with only one temporal measurement per population may not be informative. This opens stimulating questions about how pollinator behaviour and resulting pollination efficiency may vary across the flowering season.

scholarly journals Effects of sexual dimorphism on pollinator behaviour in a dioecious species

2021 ◽  
Author(s):  
Laura Moquet ◽  
Anne-Laure Jacquemart ◽  
Mathilde Dufay ◽  
Isabelle De Cauwer
Keyword(s):  
Sexual Dimorphism ◽  
Bombus Terrestris ◽  
Male Flower ◽  
Pollen Grains ◽  
Flower Size ◽  
Pollination Efficiency ◽  
Flower Number ◽  
Pollinator Behaviour ◽  
Number Of Visits ◽  
Female Flowers

Floral traits often display sexual dimorphism in insect-pollinated dioecious plant species, with male individuals typically being showier than females. While this strategy is theorized to be optimal when pollinators are abundant, it might represent a risk when they become scarce, because the disproportionately high number of visits on the most attractive sex, males, might preclude efficient pollen transfer from males to females. Here, the effect of sexual dimorphism on pollination efficiency was assessed in experimental arrays of dioecious Silene dioica that were exposed to one frequent visitor of the species, Bombus terrestris, and that differed in the magnitude of sexual dimorphism for either flower number or flower size. While flower size dimorphism did not impact pollination efficiency, we found that flower number dimorphism negatively affected the number of visits on female plants, on female flowers and on the number of female flowers visited after a male flower. However, flower number dimorphism had no effect on the number of pollen grains deposited per stigma, presumably because the decrease in the number of visits to female flowers was compensated by a higher number of pollen grains deposited per visit.

scholarly journals Ants visit nectaries of Epidendrum denticulatum (Orchidaceae) in a Brazilian rainforest: effects on herbivory and pollination

2003 ◽  
Vol 63 (4) ◽  
pp. 551-558 ◽  
Author(s):  
A. M. Almeida ◽  
R. A. Figueiredo
Keyword(s):  
Fruit Set ◽  
Reproductive Organ ◽  
Extrafloral Nectaries ◽  
Pollinator Behaviour ◽  
Pollination Success ◽  
Reproductive Structures ◽  
The Family ◽  
Ectatomma Tuberculatum ◽  
And Behavior ◽  
Brazilian Atlantic Rainforest

Epidendrum denticulatum (Orchidaceae) produces nectar on the petioles of buds, flowers, and fruits (extrafloral nectaries) but no nectar is found on its flowers, and it is probably a deceptive species. In the Brazilian Atlantic rainforest, some aspects of both the ecology and behavior of Camponotus sericeiventris (Formicinae) and Ectatomma tuberculatum (Ponerinae), two ant species foraging on E. denticulatum extrafloral nectaries, were investigated. Both experiments, using termites as baits and field observations, suggest that these ant species are able to prevent reproductive organ herbivory, without affecting pollinator behaviour. Since a low fruit set is often cited as a characteristic of the family, especially for deceptive species, ants attracted to orchid inflorescences protect reproductive structures and increase the probability of pollination success. Epidendrum denticulatum flowers were visited and probably pollinated by Heliconius erato (Nymphalidae) and Euphyes leptosema (Hesperiidae).

Pollinator behaviour, mate choice and the realised mating systems of Grevillea mucronulata and Grevillea sphacelata

2000 ◽  
Vol 48 (3) ◽  
pp. 357 ◽  
Author(s):  
Matthew B. G. Richardson ◽  
David J. Ayre ◽  
Robert J. Whelan
Keyword(s):  
Mate Choice ◽  
Mating System ◽  
Mating Systems ◽  
Fruit Set ◽  
Electrophoretic Analysis ◽  
Population Variation ◽  
Pollinator Behaviour ◽  
High Level ◽  
Almost All ◽  
Pollination Systems

Successful long-term conservation and management of populations of plants requires successful management of the suite of factors that determine their ‘realised’ mating systems. Within the genus Grevillea, mating systems are potentially complex. They may vary among species and among populations within a species, reflecting variation in pollinator behaviour and diversity (‘potential’ mating systems) and in breeding system (the ‘preferred’ mating system). We used a combination of pollinator observations, pollination experiments and electrophoretic analysis of seed from open pollinations, to examine variation in potential and preferred mating systems in two populations of each of two ‘spider-flowered’ Grevillea species: G. mucronulata (visited by honeyeaters and honeybees, although only birds effected pollen removal and transfer) and G. sphacelata (visited only by honeybees, which made frequent contact with pollen and stigmas). Almost all observed bird and insect foraging bouts on either species involved movements among inflorescences within plants or among inflorescences on closely neighbouring plants. On the basis of these data, the mating system was predicted to involve a high level of selfing or inbreeding. However, the pollination experiment revealed that both species were highly self-incompatible and showed a clear preference for outcross pollen in mate-choice experiments. For both species, fruit set through autogamy was lower than 0.7% and fruit set from self-pollinations was always significantly lower than for outcross pollinations (0–11% cf. 25–33% for G. mucronulata and 0% cf. 4.2–8.8% for G. sphacelata). Allozyme studies revealed that genotypes in open-pollinated seeds on 20 G. mucronulata and 20 G. sphacelata plants were surprisingly uniform, best explained by outcrossed matings between close neighbours. We found little between-population variation in any aspect of the mating system for either species. These studies reveal that the preferred mating system of the plant and the pattern of pollinator behaviour interact to determine the mating system in a population, emphasising the need for a multifaceted investigation of mating systems, especially in predicting the fates of populations that have pollination systems altered by disturbance, small size, isolation and introduced species such as the honeybee.

Self-compatibility, autonomous self-pollination, and insect-mediated pollination in the clonal species Iris versicolor

1993 ◽  
Vol 71 (11) ◽  
pp. 1503-1509 ◽  
Author(s):  
Paul Kron ◽  
Steven C. Stewart ◽  
Allison Back
Keyword(s):  
Reproductive Biology ◽  
Fruit Set ◽  
Pollen Grains ◽  
Clonal Plants ◽  
Pollinator Behaviour ◽  
Self Pollination ◽  
Self Compatibility ◽  
Three Stages ◽  
Pass Through ◽  
Clonal Species

In clonal species, sexual and asexual systems interact to create a hierarchy of reproduction. For example, self-pollination can occur within pollination units, flowers, ramets, or clones. We investigated the reproductive biology of a natural population of Iris versicolor using pollination manipulations and observations of pollinator behaviour. We found that (i) individuals were completely self-compatible, (ii) selfing rates were close to 100%, (iii) autonomous self-pollination can occur through stigma–anther contact or wind action, (iv) most seed and fruit set can be accounted for by insect pollination, and (v) facilitated self-pollination likely occurs because pollinators frequently visit more than one pollination unit within a flower. Our observations showed that flowers pass through three stages: (i) a male stage (in which pollen is freely available, but stigmas are inaccessible, preventing autogamy); (ii) a female stage (in which stigma flaps have reflexed and are receptive, but pollinators may have already removed most pollen grains, structuring opportunities for geitonogamy); and (iii) a strongly autogamous stage (in which stigma flaps have curled back to contact anthers, leading to delayed autonomous self-pollination). This hierarchy of relatedness among mates determines the genetic consequences of vegetative and sexual reproduction in clonal plants and influences their evolution. Key words: Iris, self-incompatibility, reproductive biology, clonal, pollination.

scholarly journals Effects of sexual dimorphism on pollinator behaviour in a dioecious species

Oikos ◽  
2021 ◽  
Author(s):  
Laura Moquet ◽  
Anne‐Laure Jacquemart ◽  
Mathilde Dufay ◽  
Isabelle De Cauwer
Keyword(s):  
Sexual Dimorphism ◽  
Dioecious Species ◽  
Pollinator Behaviour

RHYNCHOLITES AND THE PROBLEM OF NARROW AND BROAD CONCEPTION OF TAXONS

2018 ◽  
pp. 12-17 ◽  
Author(s):  
I. R. Khuzina ◽  
V. N. Komarov
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Characteristics ◽  
Mass Scale ◽  
Individual Variability ◽  
Point Of View ◽  
The Other ◽  
New Taxon ◽  
Artificial System ◽  
Broad Understanding

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

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