The self-incompatibility (SI) system is genetically controlled by a single polymorphic locus known as the S-locus in the Brassicaceae. Pollen rejection occurs when the stigma and pollen share the same S-haplotype. Recognition of S-haplotype specificity has recently been shown to involve at least two S-locus genes, S-receptor kinase (SRK) and S-locus protein 11 or S locus Cysteine-rich (SP11/SCR...

Many hermaphrodite plant species have evolved mechanisms to prevent self-fertilization. One such mechanism is self-incompatibility (SI), which is defined as the inability of a fertile hermaphrodite plant to produce zygotes after self-pollination. SI prevents self-fertilization by rejecting pollen from plants with the same genotype. The SI system in Brassica is controlled sporophytically by mult...

Gametophytic self-incompatibility (GSI) is a mechanism in flowering plants, to prevent inbreeding and promote outcrossing. GSI is under the control of a specific locus, known as the S-locus, which contains at least two genes, the RNase and the SFB. Active S-RNases in the style are essential for rejection of haploid pollen, when the pollen S-allele matches one of two S-alleles of the diploid pis...

Many plants have a genetically determined self-incompatibility system in which the rejection of self pollen grains is controlled by alleles of an S locus. A common feature of these S loci is that separate pollen- and style-expressed genes (pollen S and style S, respectively) determine S allele identity. The long-held view has been that pollen S and style S must be a coevolving gene pair in orde...

to assess the genetic relationships between 72 cultivated and 65 wild grapevines in west azerbaijan and in kurdistan, 19 ssr markers were employed. microsatellitic primer pairs amplified, a total of 163 alleles with an average of 8.6 alleles/locus (for cultivars) and 153 alleles with an average of 8.05 alleles/locus (for wild samples). the expected heterozigosity varied from 0.7 in cultivars to...

Gametophytic self-incompatibility in plants involves rejection of pollen when pistil and pollen share the same allele at the S locus. This locus is highly multiallelic, but the mechanism by which new functional S alleles are generated in nature has not been determined and remains one of the most intriguing conceptual barriers to a full understanding of self-incompatibility. The S(11) and S(13) ...

Drawing on examples from S-RNase-based self-incompatibility (SI), Slocus genealogies are used to infer the demographic history of lineages, the history of mating-system transitions in entire plant families and aspects of the evolution of the S-locus itself. Two lineages of Solanaceae suffered severe restrictions of S-locus diversity evident after millions of years. Broadly shared ancestral S-lo...