scholarly journals Cryptic dioecy in Mussaenda pubescens (Rubiaceae): a species with stigma-height dimorphism

2010 ◽  
Vol 106 (4) ◽  
pp. 521-531 ◽  
Author(s):  
Ai-Min Li ◽  
Xiao-Qin Wu ◽  
Dian-Xiang Zhang ◽  
Spencer C. H. Barrett
Keyword(s):  
Cryptic Dioecy

Cryptic dioecy in Actinidia polygama: a test of the pollinator attraction hypothesis

2004 ◽  
Vol 82 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Tetsuhiro Kawagoe ◽  
Nobuhiko Suzuki
Keyword(s):  
Fruit Production ◽  
Sexual System ◽  
Dioecious Species ◽  
Pollinator Attraction ◽  
Cryptic Dioecy ◽  
Actinidia Polygama ◽  
Unisexual Flowers ◽  
Sterile Pollen ◽  
Female Flowers

Female flowers of some dioecious species are known to develop stamens with sterile pollen, a sexual system known as cryptic dioecy. A convincing hypothesis explaining this phenomenon is that stamens in female flowers attract pollinators and so ensure seed production. However, because this hypothesis has rarely been tested experimentally, we tested it in a cryptically dioecious species, Actinidia polygama (Sieb. et Zucc.) Planch. ex Maxim. Our findings show that pollinators do not show a consistent preference based on the sex of the flowers, and that the removal of stamens from female flowers results in a significant reduction in the frequency of insect visits and fruit production. These results strongly support the pollinator attraction hypothesis in A. polygama. Given the evident role of stamens in female flowers in A. polygama reproduction, we discuss why cryptic dioecy is a rare phenomenon.Key words: Actinidia polygama, cryptic dioecy, pseudopollen, pollinator attraction, unisexual flowers.

Floral development of Rosa setigera

1993 ◽  
Vol 71 (1) ◽  
pp. 74-86 ◽  
Author(s):  
James R. Kemp ◽  
Usher Posluszny ◽  
Jean M. Gerrath ◽  
Peter G. Kevan
Keyword(s):  
Key Words ◽  
Floral Development ◽  
Functional Approach ◽  
Floral Meristem ◽  
Cryptic Dioecy ◽  
Congenital Fusion ◽  
Postgenital Fusion

The development of the flower of Rosa setigera from initiation to the onset of anthesis is described. Rosa setigera is the only known member of the genus Rosa to exhibit dioecy. Flowers of functionally staminate (male) and functionally carpellate (female) plants appear identical, a condition referred to as cryptic dioecy. Discrete sepals and petals are formed on the floral meristem. As the hypanthium forms, stamens are initiated in alternating whorls on the wall of the hypanthium and continue to develop as the hypanthium extends. Carpel primordia arise individually on the remainder of the floral meristem and show neither adnation to the hypanthial wall nor coalescence to one another as they give rise to the styles and stigmas that are exserted above the hypanthium lip. The only observable fusion in this species appears to be the postgenital fusion of the margins of the carpel primordia to form the enclosed locule. Although historically the hypanthium has been variously interpreted as either axial and (or) appendicular in nature, resulting from congenital fusion of sepals, petals, and stamens, this paper uses a more realistic, testable and functional approach to the development of the hypanthium that is in keeping with current concepts such as process morphology. Key words: Rosa setigera, dioecy, floral development, fusion, hypanthium.

scholarly journals Paternal effects on functional gender account for cryptic dioecy in a perennial plant

2004 ◽  
Vol 271 (1552) ◽  
pp. 2017-2023 ◽  
Author(s):  
Miguel Verdú ◽  
Ana I. Montilla ◽  
John R. Pannell
Keyword(s):  
Paternal Effects ◽  
Perennial Plant ◽  
Cryptic Dioecy

Cryptic dioecy in flowering plants

1991 ◽  
Vol 6 (10) ◽  
pp. 320-325 ◽  
Author(s):  
S.S. Mayer ◽  
D. Charlesworth
Keyword(s):  
Flowering Plants ◽  
Cryptic Dioecy

Cryptic dioecy in Mammea (Clusiaceae)

2004 ◽  
Vol 249 (3-4) ◽  
pp. 191-196 ◽  
Author(s):  
M. Dunthorn
Keyword(s):  
Cryptic Dioecy

scholarly journals Cryptic dioecy and leaky dioecy in endemic species of Dombeya (Sterculiaceae) on La Re´union

1999 ◽  
Vol 86 (10) ◽  
pp. 1437-1447 ◽  
Author(s):  
Laurence Humeau ◽  
Thierry Pailler ◽  
John D. Thompson
Keyword(s):  
Endemic Species ◽  
Cryptic Dioecy

Dioécie cryptique chez Geniostoma borbonica, espèce pionnière endémique de La Réunion

2003 ◽  
Vol 81 (9) ◽  
pp. 897-904 ◽  
Author(s):  
Laurence Humeau ◽  
Dominique Strasberg ◽  
Thierry Pailler
Keyword(s):  
Breeding System ◽  
Natural Populations ◽  
Pollen Grains ◽  
Floral Biology ◽  
Breeding Systems ◽  
Plant Succession ◽  
General Context ◽  
Cryptic Dioecy ◽  
Unisexual Flowers ◽  
Evolution Of Dioecy

In the general context of conservation of insular habitats, the floral biology, natural fecundity, and breeding system of Geniostoma borbonica (Lam.) Spreng. was studied in natural populations. The species, which was initially assumed to be gynodioecious, presents two kinds of individuals, both with morphological hermaphroditic but functionally unisexual flowers. Some individuals produce pollen grains, but neither ovules nor fruit, whereas other fructiferous individuals have anthers without pollen grains. Geniostoma borbonica is the first species in this genus to be reported as dioecious; its floral morphology illustrates an example of cryptic dioecy. This species combines an apomictic breeding system, assuring a fast installation without reproductive constraints, and a reproductive breeding system assuring maintenance of genetic variability in the population. These two breeding systems allow adaptation to evolution of the habitat during plant succession. This point is discussed in the colonization context of pioneer habitats, where herma- phro ditic species are recognized to be advantageous, as well as in the context of the evolution of dioecy in this genus.Key words: cryptic dioecy, pioneer habitat, oceanic island, Geniostoma.

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