Tagged: fruit-set

Continuous variation in herkogamy in Mediterranean honeysuckle populations

Herkogamy, the spatial separation of sex organs in hermaphroditic plants, is thought to have evolved to reduce self-pollination and inbreeding within a population. Yet there has been little evidence to support these hypotheses. Much work in this field has focussed on heterostyly, in which two or three distinct and reciprocal herkogamy morphs are found in the same breeding population. The study of continuous variation in herkogamy, in which plants exhibit continuous variation in the separation of sex organs, has received far less attention. However, it warrants further attention, because the positions of plant sex organs can have profound implications for...

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toadflax Linaria cavanillesii

Mixed mating after the loss of self-incompatibility in a long-living perennial herb

Flowering plants display an extensive range of adaptive floral forms, which are often correlated with their mating systems. The maintenance of contrasting strategies such as those adopted by obligate outcrossers compared to populations that have evolved a selfing system is one of the most studied topics in reproductive evolution. Voillemot and Pannell study variation in mating systems in Spanish toadflax Linaria cavanillesii, a long-lived perennial species. Some unexpected features are reported, such as an absence of shift in flower morphology in the self-compatible population, together with the maintenance of outcrossing despite no apparent inbreeding depression.

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High male fertility in males of a subdioecious shrub

Female reproductive success in females versus hermaphrodites has been well documented. However, documenting a potential advantage in fertility of male versus hermaphrodite individuals in subdioecious species is also essential for understanding the evolutionary pathway from hermaphroditism toward dioecy via gynodioecy. In a recent study published by Wang et al. in AoB PLANTS, siring success in terms of fruit set, fruit mass, number of seeds, and mean seed mass was compared by hand-pollinated crosses in the subdioecious shrub Eurya japonica. Male individuals exhibited an advantage in male fertility in terms of both quantity and quality compared with hermaphrodites in hand-pollinated crosses...

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Lonicera etruscas superba

Effect of nectar robbing on a pollinator-dependent plant

Nectar robbing commonly has negative consequences for the reproductive success of plants. Because total plant fitness is the result of both female and male functions, Rojas-Nossa et al. studied the effect of nectar robbing on several variables used to characterize both sexual functions of Lonicera etrusca, a pollinator-dependent plant with long tubular flowers that produce abundant nectar. Although nectar robbing was very frequent, no negative consequence for plant reproductive success was found. They propose a combination of morphological and ecological mechanisms that allow plants to compensate for the energetic loss caused by robbers.

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Pollinator limitation on reproductive success in Iris tuberosa

Variation in plant and floral size can have conflicting effects on pollination and fruit production in flowering plants. In a new study published in AoB PLANTS, Pellegrino measured the effect of varying pollinator visits on fruit production in order to understand pollination strategy in Iris tuberosa, and assessed the effects of plant and floral display size on pollination to understand how these factors influence reproductive success. He found that I. tuberosa was pollinated exclusively by hymenopteran species, mainly during sunny days, and that plant and floral size did not affect fruit set and pollinator attraction. Thus, the sexual reproduction of...

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Ants mediate plant reproductive traits

Ants mediate plant reproductive traits

The selection of floral and reproductive traits is influenced by the plant’s abiotic environment, florivores and pollinators. Leroy et al.  show that mutualistic associations with ants can result in an enhanced reproductive allocation for the tank‐bromeliad Aechmea mertensii. They find that association with Camponotus femoratus results in more and larger inflorescences, more flowers and fruits, and more and larger seeds than for plants associated with Pachycondyla goeldii. Thus the different activities and ecological preferences of these two ant species may play a contrasting role in shaping the evolution and speciation of this bromeliad.

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