Seed and pollen flow and cline discordance among genes with different modes of inheritance

Abstract

The relationships between seed and pollen flow and cline discordance/concordance between cytoplasmic and nuclear genes, with the incorporation of the effects of natural selection, are formulated for one locus with two alleles, under assumptions of random mating, no drift and no mutation. Results show that under certain conditions, the relative roles of seed and pollen flow in shaping cline discordance/ concordance are very similar to their roles in influencing population differentiation for selectively neutral markers with different modes of inheritance. Where the disequilibria

Migration load in plants: role of pollen and seed dispersal in heterogeneous landscapes

“…, 2006). Few theoretical models exploring the effect of gene flow on genetic load and local adaptation explicitly deal with pollen and seed dispersal (Nagylaki, 1997; Hu & Li, 2001, 2002; Hu, 2005). The number of gene copies carried by a migrating seed is twice that carried by a migrating pollen grain.…”

Barriers to the Spread of Neutral Alleles in the Cytonuclear System

“…These theoretical predictions highlight the significance of cytonuclear disequilibrium as a biological barrier or the joint effects of biological and physical barriers in generating transient neutral clines. The results also help us to interpret the empirical studies with molecular markers when cytonuclear clines are jointly examined in the hybrid zone with a short history (Hu and Li 2002; Watano et al 2004).…”

“…A diallelic selective site is considered on each of two haploid organelle genomes, with the B and b alleles on the organelle genome of paternal inheritance, and the C and c alleles on the organelle genome of maternal inheritance. Effectiveness of seed and pollen dispersal in spreading these alleles is related to their modes of inheritance (Hu and Li 2002).…”

“…and indicate that the B and C alleles evolve independently although seed dispersal can generate disequilibrium between paternal and maternal organelle alleles (eq. [5f]; Hu and Li 2002). indicates that the evolution of the neutral nuclear allele is affected by the cytonuclear disequilibrium ( D QB and D QC ) produced by seed and pollen dispersal ( and ).…”

“…The biparentally inherited diploid nuclear genomes spread through both seeds and pollen dispersal. These contrasting modes of inheritance affect population genetic structure (Ennos 1994; Hu and Ennos 1997; Ennos et al 1999; Hu and Ennos 1999) and cline shapes in hybrid zones (Hu and Li 2001, 2002; Johansen and Latta 2003). Cytonuclear disequilibrium is not only related to the mode of genome inheritance (paternal, maternal, and biparental) but also to the vectors of diploid seeds and haploid pollen dispersal.…”