M. van Kleunen ([email protected]) and S. D. Johnson, Centre for Invasion Biology, School of Biological and Conservation Sciences, Univ. of KwaZulu-Natal, P. Bag X01 Scottsville, Pietermaritzburg 3209, South Africa. M. Fischer and present address for MvK: Inst. of Plant Sciences, Univ. of Bern, CH-3013 Bern, Switzerland. MF also at: Inst. for Biochemistry and Biology, Univ. of Potsdam, Maul...

Many plant species have been introduced from their native ranges to new continents, but few have become naturalized or, ultimately, invasive. It has been predicted that species that do not require the presence of compatible mates and the services of pollinators for reproduction will be favored in establishment after long-distance dispersal. We tested whether this hypothesis, generally referred ...

Sexual reproduction shuffles genetic variation, potentially enhancing the evolutionary response to environmental change. Many asexual organisms respond to stress by generating facultative sexual reproduction, presumably as a means of escaping the trap of low genetic diversity. Self-fertilizing organisms are subject to similar genetic limitations: the consistent loss of genetic diversity within ...

In Paramecium, age is defined as the number of mitotic divisions which have elapsed since the previous cross-fertilization (conjugation) or self-fertilization (autogamy). As the mitotic interval between fertilizations increases, the percentage of nonviable progeny clones increases. In the current study, resolution of conflicting previous reports on the pattern of increase of death and reduced v...

The evolution of predominant self-fertilization from cross-fertilization in plants is accompanied by diverse changes to morphology, ecology and genetics, some of which likely result from regulatory changes in gene expression. We examined changes in gene expression during early stages in the transition to selfing in populations of animal-pollinated Eichhornia paniculata with contrasting mating p...

Sexual selection is often quantified using Bateman gradients, which represent sex-specific regression slopes of reproductive success on mating success and thus describe the expected fitness returns from mating more often. Although the analytical framework for Bateman gradients aimed at covering all sexual systems, empirical studies are biased toward separate-sex organisms, probably because impo...

Global food security demands the development and delivery of new technologies to increase and secure cereal production on finite arable land without increasing water and fertilizer use. There are several options for boosting wheat yields, but most offer only small yield increases. Wheat is an inbred plant, and hybrids hold the potential to deliver a major lift in yield and will open a wide rang...

If the competitive ability of plants produced by self-pollination differs from that of plants derived by outcrossing, then the magnitude of inbreeding depression may be influenced by the composition of the competitive environment (i.e., the frequency of plants that have arisen from selfing and outcrossing in the neighborhood of "target" plants in which inbreeding depression is expressed). Here,...

HE paper “Ana1ys.k of models with homozygote x heterozygote matings“ was devoted to the complete mathematical analysis of the equilibrium behavior of some models proposed by SCUDO (1964) and FINNEY (1952) and some of their qualitative implications for population genetics in general. In this paper we repeat this process with certain models described by WORKMAN ( 1964), NAYLOR (1962) and others. ...

almond is one of the most important prunus species. most almond cultivars and genotypes are self-incompatible and some others are cross-incompatible. however, recently self-incompatible cultivars developed by breeding are available. therefore self-incompatible cultivars for pollination, fertilization and production require compatible pollen of other cultivars. in this regard the study of pollen...