A M O N G the mechanisms restricting the flow of genes between discrete populations of plants, unilateral incompatibility (UI) is unique in that one of the reciprocal crossing combinations succeeds whereas the other fails. The term unilateral incompatibility is generally restricted to a phenomenon thought to be closely related to self-incompatibility (SI), for it occurs in matings of self-ferti...

Many flowering plants are unable to set seeds with their own pollen because a system known as gametophytic self-incompatibility is operating. The basis of this system is a single multiallelic locus S, and if the S allele carried by a pollen grain matches one of the two S alleles carried in the style, as it is certain to do upon self-pollination, then pollen tube growth is inhibited. Should one ...

Recently, an S haplotype-specific F-box (SFB) gene has been proposed as a candidate for the pollen-S specificity gene of RNase-mediated gametophytic self-incompatibility in Prunus (Rosaceae). We have examined two pollen-part mutant haplotypes of sweet cherry (Prunus avium). Both were found to retain the S-RNase, which determines stylar specificity, but one (S3' in JI 2434) has a deletion includ...

In Brassica species, self-incompatibility has been mapped genetically to a single chromosomal location. In this region several closely linked genes have been identified. One of them, S-locus receptor kinase (SRK), determines S haplotype specificity of the stigma and it's the key protein for SI reaction. The role of the S locus glycoprotein (SLG) gene remains unclear. In the last decade approxim...

For a system of n self-incompatibility alleles, neglecting mutation and random drift, it is shown that the completely symmetric equilibrium is locally stable, and any allelic frequency less than q equals 1 + a minus the square root of 1 + a-2, where a equals [2(n minus 1)]- minus 1, will increase. For all n, q greater than (2n)- minus 1, but if n greater than 1, q is approximately equal to (2n)...

There has been much discussion recently of what has been labeled the “Brown-Boghossian-McKinsey”, “Brown-McKinsey” or sometimes just “McKinsey” arguments for the incompatibility of externalism and self-knowledge. However, while the three author’s arguments have been treated as interchangeable, they are not identical. In particular, Brown’s and Boghossian’s arguments have a fairly serious flaw t...

Non-self recognition is a common phenomenon among organisms; it often leads to innate immunity to prevent the invasion of parasites and maintain the genetic polymorphism of organisms. Fungal vegetative incompatibility is a type of non-self recognition which often induces programmed cell death (PCD) and restricts the spread of molecular parasites. It is not clearly known whether virus infection ...