Quantitative trait loci controlling vegetative propagation traits mapped in European pear (<Emphasis Type="Italic">Pyrus communis</Emphasis> L.)

The ease of vegetative propagation by hardwood cuttings is a critical trait for consideration by breeders of woody perennial rootstocks. This is especially so for Pyrus, because most Pyrus rootstock are known to be difficult to propagate. This report presents progress on the identification of loci controlling rooting of hardwood cuttings in European pear (Pyrus communis L.). Quantitative trait loci (QTLs) controlling the development of adventitious roots on hardwood cuttings were identified in both parents of a mapping population developed by crossing “Old Home” and “Louise Bonne de Jersey,” with the goal of investigating the genetic control of several rootstock related traits, which would be useful for rootstock breeding. A QTL for root development was identified on chromosome 7, co-located in both parents and exhibiting male and female additive and dominance effects. These results will assist in developing genetic markers that can be utilized by rootstock breeders for marker-assisted selection for this complex trait.