Interspecific hybridisation and interaction with cultivars affect the genetic variation of Ulmus minor and U. glabra in Flanders

Interspecific hybridisation and gene flow from cultivated plants may have profound effects on the evolution of wild species. Considering the cultural history and past use of U. minor and U. glabra trees in Flanders (northern Belgium), we investigated the extent of human impact on the genetic variation of the remaining, supposedly indigenous elm populations. We therefore examined the rate of interspecific hybridisation, which is expected to be higher under human influence, the occurrence of clones within and among locations, the presence of cultivars and their possible offspring. Based on results produced using 385 Amplified Fragment Length Polymorphic (AFLP) markers, 46% of the 106 investigated Flemish elms appeared to be F1 hybrids or backcrosses to one of the parent species, while no F2 hybrids (F1 x F1 progeny) were found. Clonality was mainly found among U. minor and hybrids, which are more likely to form root suckers or sprouts as opposed to U. glabra. The majority of the studied l...

种间杂交与栽培植物的基因流可能对野生物种的演化产生深远影响。鉴于比利时北部佛兰德斯地区U. minor与U. glabra榆树的栽培历史及既往应用情况，我们探究了人类活动对现存疑似原生榆属种群遗传变异的影响程度。为此，我们分析了种间杂交率——预期在人类活动影响下该比率会升高——、不同地点内及地点间的克隆株出现情况，以及栽培品种及其可能后代的存在情况。基于385个扩增片段长度多态性（AFLP）标记的分析结果，在被调查的106株佛兰德斯榆树中，有46%为F1杂交种或回交到其中一个亲本物种的回交后代，未发现F2杂交种（F1×F1子代）。克隆性主要见于U. minor与杂交株中，相较于U. glabra，这两类植株更易产生根蘖或萌条。本研究的多数