نتایج جستجو برای: fertilization self

تعداد نتایج: 558042  

Journal: :Journal of evolutionary biology 2005
E Porcher R Lande

We model the evolution of plant mating systems under the joint effects of pollen discounting and pollen limitation, using a dynamic model of inbreeding depression, allowing for partial purging of recessive lethal mutations by selfing. Stable mixed mating systems occur for a wide range of parameter values with pollen discounting alone. However, when typical levels of pollen limitation are combin...

Journal: :Proceedings. Biological sciences 2002
Pierre-Olivier Cheptou Ulf Dieckmann

The evolution of selfing in hermaphrodites has been studied to reveal the demographic conditions that lead to intermediate selfing rates. Using a demographic model based on Ricker-type density regulation, we assume first that, independent of population density, inbred individuals survive less well than outbred individuals and second, that inbred and outbred individuals differ in their competiti...

Journal: :Molecular ecology 2004
Vincent Castric Xavier Vekemans

Self-incompatibility systems in plants are genetic systems that prevent self-fertilization in hermaphrodites through recognition and rejection of pollen expressing the same allelic specificity as that expressed in the pistils. The evolutionary properties of these self-recognition systems have been revealed through a fascinating interplay between empirical advances and theoretical developments. ...

Journal: :Evolution; international journal of organic evolution 2017
Diala Abu Awad Sylvain Billiard

Phylogenies indicate that the transition from outcrossing to selfing is frequent, with selfing populations being more prone to extinction. The rates of transition to selfing and extinction, acting on different timescales, could explain the observed distributions of extant selfing species among taxa. However, phylogenetic and theoretical studies consider these mechanisms independently, that is t...

Journal: :Genetics 2008
Badri Padhukasahasram Paul Marjoram Jeffrey D Wall Carlos D Bustamante Magnus Nordborg

We present an exact forward-in-time algorithm that can efficiently simulate the evolution of a finite population under the Wright-Fisher model. We used simulations based on this algorithm to verify the accuracy of the ancestral recombination graph approximation by comparing it to the exact Wright-Fisher scenario. We find that the recombination graph is generally a very good approximation for mo...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1973
R K Selander D W Kaufman

The pulmonate land snail Rumina decollata in its native Mediterranean range is a complex of monogenic or weakly polygenic strains generated by a breeding system of facultative self-fertilization. One strain colonized North America and now occupies much of the southern United States and northern Mexico. No genetic variation within or among populations in the United States was detected in an elec...

Journal: Journal of Nuts 2015
A. Ghanbari A. Kamareh Y. Sharafi

The almond, Prunus dulcis Miller which belongs to Rosaceae family, is one of the most important commercial and oldest cultivated tree nut crops. Almonds are classified as a ‘nut’ in which the edible seed is the commercial product. Therefore, pollination and fertilization are necessary in almond. The characteristic of cultivated almond to express gametophytic self- incompatibility discourages se...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1999
R Marino R De Santis P Giuliano M R Pinto

In the hermaphrodite ascidian Ciona intestinalis, the egg vitelline coat (VC) controls gamete self-nonself discrimination. Oocytes, after germinal vesicle breakdown, can be fertilized by both self and nonself sperm. However, a barrier to fertilization by self sperm progressively develops in the VC in the 3 hours after germinal vesicle breakdown. During this period, follicle cells attached to th...

Journal: :The International Journal of Developmental Biology 2008

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