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Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals ( dioecy ), and their various modes of spatial ( herkogamy ) and temporal ( dichogamy ) separation.
For this reason, most plants have genetic mechanisms to prevent fertilization from pollen grains that are too closely related to the stigma (self-incompatibility). The mechanisms of breeding systems occur at the molecular level through a biochemical reaction on the stigma that recognizes genetic differences in pollen grains.
The transition to self-compatibility in Arabidopsis thaliana and evolution within S-haplotypes over 10 million years. Molecular Biology and Evolution 23: 1741–1750. Asher D. Cutter, Scott E. Baird and Deborah Charlesworth. 2006 Patterns of nucleotide polymorphism and the decay of linkage disequilibrium in wild populations of Caenorhabditis ...
In essence, self-incompatibility mechanisms are highly specific self/nonself mate recognition systems which confer on cells of the pistil the ability to discriminate between pollen grains that are defined as “self” and “nonself” on the basis of genetic identity at self-incompatibility loci, resulting in specific inhibition of “self ...
Distyly is a type of heterostyly in which a plant demonstrates reciprocal herkogamy.This breeding system is characterized by two separate flower morphs, where individual plants produce flowers that either have long styles and short stamens (L-morph flowers), or that have short styles and long stamens (S-morph flowers). [1]
A doubled haploid (DH) is a genotype formed when haploid cells undergo chromosome doubling. Artificial production of doubled haploids is important in plant breeding.. Haploid cells are produced from pollen or egg cells or from other cells of the gametophyte, then by induced or spontaneous chromosome doubling, a doubled haploid cell is produced, which can be grown into a doubled haploid plant.
Certain restrictions caused the mechanisms for self-fertilization (partial and full self-fertilization) to develop in a number of plant species. Some of the reasons why a self-fertilizing method of reproduction is so effective are the efficacy of reproduction, as well as decreasing genetic variation and thus the fixation of highly adapted ...
Cryptic self-incompatibility (CSI) is the botanical expression that's used to describe a weakened self-incompatibility (SI) system. [1] CSI is one expression of a mixed mating system in flowering plants. Both SI and CSI are traits that increase the frequency of fertilization of ovules by outcross pollen, as opposed to self-pollen.