Introgression of fitness genes across a ploidy barrier.

摘要: Gene flow from diploid to polyploid species could have significant effects on the morphology and ecology of polyploids. The potential such introgression for bringing about evolutionary change within polyploids has long been recognized, although there are few examples process in wild. Here, we focus between species, Senecio squalidus, tetraploid, S. vulgaris, which resulted origin a variant form vulgaris that produces radiate rather than nonradiate flower heads. is more attractive pollinators higher outcrossing rate. We review recent work isolated characterized two regulatory genes, RAY1 RAY2, control presence ray florets heads, introgressed into squalidus past. identify copy RAY2 (RAY2b) homeologous (RAY2a) previously isolated, thus providing further evidence allotetraploid. also show RAY2a-R allele, fixed occurs at intermediate frequency squalidus. Thus, based this result, it not possible distinguish whether originated once or multiple times following hybridization