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Exceptions from dioecy and sex lability in genus Salix

100%

Mirski P.

Dendrobiology

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2014

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tom 71

Bisexualism (and its derivatives) is a rare exception in species which already acquired the dioecious breeding system. Although it occurs in some tree species, it is still rather uncommon, except for willows, in which bisexualism occurs in at least 18 species. In most willows such unusual individuals are subdioecious, hermaphroditic or monoecious, or produce intersexes (staminate flowers transform into pistillate flowers or the other way round). The frequency of non-dioecy can vary from a single individual to whole populations, but is in principle rare. Its possible causes are both environmental and genetic. In Salix sex lability is known to be affected by parasites and anthropogenic habitat change. In interspecific willow crosses there are numerous exceptions from dioecy that are mostly caused by polyploidization. Since sex determination in willows is genetic, environmental factors are expected to determine exclusively phenotypic sex traits.

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Histology of reproductive systems of goat hermaphrodites

100%

Dabrowski T., Szatkowska I., Sysa P.

Annals of Animal Science

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2002

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tom 02

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nr 1

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Development of reproductive organs of Helix lutescens Rossm. [Gastropoda, Pulmonata]

84%

Koralewska-Batura E.

Biological Bulletin of Poznań

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1994

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tom 31

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Gonad development and reproduction in the monoecious species Chlorophthalmus agassizi (Actinopterygii: Aulopiformes: Chlorophthalmidae) from the Sardinian waters (central-western Mediterranean)

67%

Cabiddu S., Follesa M. C., Porcu C., Cau A.

Acta Ichthyologica et Piscatoria

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2010

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tom 40

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nr 2

Background. The shortnose greeneye, Chlorophthalmus agassizi Bonaparte, 1840, is a species with a circumglobal distribution and is among the most abundant commercial fishes in some Mediterranean areas. The knowledge of the biology and ecology of this species is poor and geographically limited, then the aim of this study is to provide a contribution to the knowledge on the reproductive biology of this monoecious deep-sea fish in Sardinian waters. Materials and Methods. In this paper the morphology and the development of the gonads, the mean size at maturity, the monthly evolution in the percent frequency of the maturity stages, and of the indices related to reproduction of the shortnose greeneye were examined. Individuals were caught by trawls, between 270 and 504 m of depth in the Sardinian seas. Results. The ovarian pattern is of an asynchronous type, characterized by releasing of eggs in successive batches. Seven stages of development for the ovary and four for the testis were identified on the basis of macroscopic and histological features. The female portion is the most evident component and shows a later maturation than the male portion. The spawning period is unique and takes place from May to September. Conclusion. The identification of spawning period and the adopted reproductive strategy is essential to obtain a better understanding of its biology and a good management of its fisheries.

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Cases of hermaphroditism in the Ukrainian populations of Unionidae

67%

Yanovych L. M., Pampura M. M., Vasilieva L. A.

Folia Malacologica

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2012

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tom 20

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nr 1

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Are hermaphrodites better adapted to the colonization process in trioecious populations of Salix myrsinifolia?

67%

Mirski P., Brzosko E.

Acta Societatis Botanicorum Poloniae

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2015

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tom 84

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nr 2

In trioecious plant populations, the role of hermaphroditism is often uncertain. We investigated the advantages of hermaphroditism in the dioecious shrub Salix myrsinifolia. The sex ratio of 30 S. myrsinifolia populations in northeastern Poland (secondary range) and Lithuania (primary range) was investigated in 2010-2011. Measures of reproductive (number of catkins, number of flowers in catkins) and vegetative traits (height, diameter, number of shoots, vitality) were taken and compared among sexual morphs. In two populations, measurements collected 14 years prior on marked individuals were used to determine the rate of changes in height, crown diameter and survivorship rates. We found trioecy mostly in the secondary part of the range with an average share of hermaphrodites reaching 21% in the trioecious populations. The sex ratio varied between populations, but tended mostly towards female domination. Several traits differed significantly among sexes. The characteristics of hermaphrodites were often intermediate between males and females and provided no evidence for the higher competitive abilities of hermaphrodites. We concluded that the possible gain of hermaphroditism in the colonization process is restricted to reproduction. We consider hermaphroditism in S. myrsinifolia as an equilibrium between the allocation of resources for growth and reproduction in unstable conditions on the margins of the range.

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Postembryonal development of reproductive organs of the selected species of families Lymnaeidae and Succineidae [Gastropoda, Pulmonata]

67%

Jackiewicz M., Zboralska H.

Bulletin de la Societe des Amis des Sciences et des Lettres de Poznan. Seria D: Science Biologiques

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1994

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tom 30

Ograniczanie wyników

1 Acta Ichthyologica et Piscatoria

1 Acta Societatis Botanicorum Poloniae

1 Annals of Animal Science

1 Biological Bulletin of Poznań

1 Bulletin de la Societe des Amis des Sciences et des Lettres de Poznan. Seria D: Science Biologiques

1 Dendrobiology

1 Folia Malacologica

2 Mirski P.

1 Brzosko E.

1 Cabiddu S.

1 Cau A.

1 Dabrowski T.

1 Follesa M. C.

1 Jackiewicz M.

1 Koralewska-Batura E.

1 Pampura M. M.

1 Porcu C.

1 Sysa P.

1 Szatkowska I.

1 Vasilieva L. A.

1 Yanovych L. M.

1 Zboralska H.

1 2015

1 2014

1 2012

1 2010

1 2002