Germination, reproduction and interference in the amphicarpic annual Emex spinosa (L.) Campd

Weiss, P. W.

doi:10.1007/bf00346465

Cited by 95 publications

(94 citation statements)

References 16 publications

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“…These fruits co-develop with vegetative growth along the shoot internodes. In contrast, subterranean achenes are produced at the base of the plant, lack spines, are never shed from the mother plant (Evenari et al 1977), and produce seedlings that are more competitive compared to aerial achenes (Weiss 1980). After germination, the plant grows into a rosette, at which stage subterranean flowering occurs.…”

Section: Natural Historymentioning

confidence: 94%

“…After germination, the plant grows into a rosette, at which stage subterranean flowering occurs. As far as conditions allow (Weiss 1980), the plant continues to grow, while maturing subterranean fruit and developing a shoot that carries aerial flowers on the internodes.…”

Section: Natural Historymentioning

confidence: 99%

“…Adopting Philippi and Seger's (1989) terminology of phenotypes, between years subterranean fruit represent a ''bad'' year, low-risk phenotype, germinating in a proven site, and facilitated by the mother plant (Weiss 1980). On the other hand, following rainy seasons, numerous new patches become available for colonization, making the dispersible aerial fruit a ''good'' year phenotype.…”

Section: Introductionmentioning

confidence: 99%

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Plastic bet-hedging in an amphicarpic annual: an integrated strategy under variable conditions

et al. 2007

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Amphicarpy is a form of diversified bet-hedging expressed mostly in annual plants, where two types of offspring are produced with two distinct ecological roles: longrange aerial dispersers and highly competitive subterranean, sedentary fruit. Emex spinosa is a semi-arid, amphicarpic annual, inhabiting habitats with different levels of environmental variation. We tested the hypothesis that, in E. spinosa, bet-hedging may be ''finetuned'' by plasticity in the phenotype ratio (aerial/subterranean fruit mass) as a function of environmental conditions. We conducted a greenhouse experiment, manipulating nutrient availability and intraspecific density, to determine the pattern of ratio shifts. In order to determine whether the integrated strategy is an adaptation to variable habitats, a similar common garden experiment was conducted, comparing two natural populations differing in environmental variability. The offspring ratio shifted in response to both nutrient availability and plant density. In pots containing single plants the ratio increased steeply with nutrient availability, while in pots containing eight plants a more moderate increase occurred. These shifts were the result of plasticity in allocation to both achene types, as well as ontogenetic effects on aerial achene production. The degree of response increased with the heterogeneity of the habitat of origin. We found evidence for an adaptive integrated strategy, with bet-hedging ''fine-tuned'' by phenotypic plasticity. Strenuous conditions tended to shift the offspring ratio towards securing subterranean reproductive success, while favorable conditions resulted in a shift towards dispersible achenes.

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Section: Natural Historymentioning

confidence: 94%

Section: Natural Historymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Plastic bet-hedging in an amphicarpic annual: an integrated strategy under variable conditions

et al. 2007

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“…Amphicarpaea bracteata is a classical example (Schnee & Wailer 1986). At the further stage plants produce cleistogamous flowers and fruits only below the ground, like in Emex spinosa (Weiss 1980) and Cardamine chenopodifolia (Cheplick 1983). At last, an intriguing form of amphicarpy has evolved, called pessimistic by Zeide (1978).…”

Section: Hypothetical Evolution Of Amphicarpy and Its Ecological Consmentioning

confidence: 99%

On the ecology and evolution of annual plants in disturbed environments

Symonides

1988

Vegetatio

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This paper is concerned with the effect of disturbance on some crucial characteristics of annual plants. The theoretically optimal life-history traits that maximize individual fitness in disturbed environments are described and critically evaluated. It seems that none of them holds for all annual species.Self-pollination and especially seed polymorphism are considered important adaptations to life in unpredictable environments. The thesis is put forward that amphicarpic annuals, which exhibit both self-pollination and extreme seed polymorphism, are best adapted to life in hazardous habitats. The hypothetical course of the evolution of amphicarpy is demonstrated on the grounds of the comparison of contemporary annual species producing chasmogamous and cleistogamous flowers on a single individual.Nomenclature: follows Flora Europaea (Tutin et al. 1964(Tutin et al. -1980, except for non-European species where the nomenclature used in the papers cited has been followed.

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“…In this study we analyze flower production and sex ratio in response to light intensity of 2 populations of Emex spinosa (L.) Campd., a Mediterranean amphicarpic annual that occurs in habitats with different levels of environmental variation (Weiss, 1980;Ortiz et al, 2009;Sadeh et al, 2009). Architectural effects have been previously found to affect reproductive traits of Emex spinosa (Ortiz et al, 2009), and we postulate that architecture may also be affected by environmental conditions; in particular, we could expect a different degree of phenotypic plasticity at different architectural levels.…”

mentioning

confidence: 99%

Plasticity and within plant sex-ratio variation in monoecious Emex spinosa

Berjano

Arista²,

Talavera³

et al. 2014

Turk J Bot

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Understanding how phenotype trait expression varies at different levels of biological organization is crucial to understanding the fundamental ecological, evolutionary, and developmental issues that contribute to adaptive plasticity. This is particularly important in plants because of their modular organization. Here, we study plasticity in flower production in response to light intensity at 3 levels of biological organization (between populations, among individuals, and within individuals) in Emex spinosa (L.) Compd., a Mediterranean amphicarpic annual. Plants exposed to high light intensity grew faster and produced more flowers than plants at low light intensity. Female flower production was the most labile trait. Within individuals, the production of female and male flowers, and the floral sex ratio strongly varied along the stems. Light intensity only significantly affected flower production at central and terminal positions in the inflorescence, while sex ratio was invariable to light intensity in each position, reflecting a sexual specialization independently of light, from initial femaleness towards maleness at the end of flowering. In Emex spinosa, the production of selfing fruits seems not only to concern ground fruits, but also early aerial fruits.

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Germination, reproduction and interference in the amphicarpic annual Emex spinosa (L.) Campd

Cited by 95 publications

References 16 publications

Plastic bet-hedging in an amphicarpic annual: an integrated strategy under variable conditions

Plastic bet-hedging in an amphicarpic annual: an integrated strategy under variable conditions

On the ecology and evolution of annual plants in disturbed environments

Plasticity and within plant sex-ratio variation in monoecious Emex spinosa

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