Breakdown of self-incompatibility in tetraploid Lycopersicon peruvianum: inheritance and expression of S-related proteins

A novel mating system analysis for modes of self-oriented mating applied to diploid and polyploid arctic Easter daisies (Townsendia hookeri)

“…The transition from diploidy to tetraploidy may either directly cause a shift towards greater selfing, through breakdowns in systems of selfincompatibility (Chawla et al, 1997;Stone, 2002), or indirectly cause an increase in selfing, through selection for increased selfing during the establishment of a neopolyploid undergoing a minority cytotype disadvantage (Ramsey and Schemske, 1998). As well, in tetraploids, it is predicted that inbreeding depression should be reduced (Husband and Schemske, 1997), although this has been rarely tested.…”

“…Polyploidy, the possession of more than two complete chromosome sets, is a common class of genome change throughout plants and animals (reviewed in Otto and Whitton, 2000). Polyploidy is known to impact selfing ability in some organisms (Stebbins, 1950;Levin, 1983;Cook and Soltis, 2000; but see Mable, 2004), may lead to a breakdown of self-incompatibility (Chawla et al, 1997;Stone, 2002) and may be accompanied by relaxed inbreeding depression (Husband and Schemske, 1997) although increased inbreeding depression may also occur depending on the mode of gene action (Ronfort, 1999). Polyploidy is also associated with asexual reproduction, in fact, 99% of all known apomictic plants are polyploid but usually for asymmetric or odd ploidy levels (Nogler, 1984;Asker and Jerling, 1992).…”

Inheritance and dominance of self-incompatibility alleles in polyploid Arabidopsis lyrata

“…These regions are often referred to as S-loci, with variants referred to as S-alleles or S-haplotypes. In one of the best-characterized systems, gametophytic SI (GSI: where the recognition phenotype of the pollen is determined by its own haploid genotype), polyploidization has been reported to disrupt the process, via competition among alleles in diploid pollen (eg, Lewis, 1947;Chawla et al, 1997;Stone, 2002). This is apparently a genotype-dependent effect in at least some species (reviewed in Mable, 2004b), but there are a relatively large number of tetraploid GSI species with increased potential for self-compatibility compared to their diploid relatives (Miller and Venable, 2000).…”

Unreduced 2n Pollen Production in ‘Nishiuchi Konatsu’ Hyuganatsu as Inferred by Pollen Characteristics and Progeny Ploidy Level

“…The breakdown of self-incompatibility accompanying polyploidy in S-RNase-based GSI species of Solanaceae, and the subfamily Maloideae of Rosaceae is a result of "competitive interaction" (e.g. Golz et al, 2001;Sassa et al, 2010;Yamane and Tao, 2009) in which pollen grains containing two copies of the same pollen-S allele (homoallelic pollen) are arrested if the cognate S-RNase is present in the style, while pollen grains containing two different pollen-S alleles (heteroallelic pollen) are compatible, regardless of the S-RNase composition of the style (Chawla et al, 1997;Kao and Tsukamoto, 2004;Luu et al, 2001). Since the selfincompatibility of the genus Citrus is assumed to be GSI type (Ollitrault et al, 2007), although it is so far unclear whether the mechanism is governed by S-RNase or not, the breakdown of incompatibility by 2n pollen of 'Nishiuchi Konatsu' seems to be attributed to a system like the competitive interaction.…”