Natural hybridisation between Populus nigra L. and P. x canadensis Moench. Hybrid offspring competes for niches along the Rhine river in the Netherlands

Abstract

Black poplar (Populus nigra L.) is a major species for European riparian forests but its abundance has decreased over the decades due to human influences. For restoration of floodplain woodlands, the remaining black poplar stands may act as source population. A potential problem is that P. nigra and Populus deltoides have contributed to many interspecific hybrids, which have been planted in large numbers. As these Populus x canadensis clones have the possibility to intercross with wild P. nigra trees, their offspring could establish themselves along European rivers. In this study, we have sampled 44 poplar seedlings and young trees that occurred spontaneously along the Rhine river and its tributaries in the Netherlands. Along these rivers, only a few native P. nigra L. populations exist in combination with many planted cultivated P. x canadensis trees. By comparison to reference material from P. nigra, P. deltoides and P. x canadensis, speciesspecific AFLP bands and microsatellite alleles indicated that nearly half of the sampled trees were not pure P. nigra but progeny of natural hybridisation that had colonised the Rhine river banks. The posterior probability method as implemented in NewHybrids using microsatellite data was the superior method in establishing the most likely parentage. The results of this study indicate that offspring of hybrid cultivated poplars compete for the same ecological niche as native black poplars.

Biomass production of Populus nigra L. clones grown in short rotation coppice systems in three different environments over four rotations

“…(Bisoffi & Gullberg 1996) or P. nigra and P. maximowiczii Henry (Stanton et al 2010). Such hybrids are capable of successfully pollinating and breeding with wild populations of P. nigra, and consequently are a threat to the genetic purity of this indigenous species (Cagelli & Lefèvre 1995, Benetka et al 2002, Smulders et al 2008. The spread of these hybrids and the contamination of P. nigra gene pools has lead in certain places to restrictions being placed on their cultivation.…”

Phylogenetic relationships in Betula (Betulaceae) based on AFLP markers

“…Therefore, it is expected that the AFLP marker variation in our data set is a suitable indicator of Betula relationships. Arens et al (1998), Cervera et al (2005), Ziegenhagen et al (2008), and Smulders et al (2008) demonstrated in poplar that the AFLP pattern of hybrid offspring contains bands of both parental species. Therefore, the comparison of AFLP patterns of taxa may serve to identify hybrids.…”

Züchtung und Ertragsleistung schnellwachsender Baumarten im Kurzumtrieb

“…In der Generation '1' sind dem Schema nach in 25 % der Rückkreuzungen noch P. deltoides Allele in der Population zu finden. In der Generation '2' wird dieser Anteil auf 12,5 % reduziert und in Generation '7' beträgt der Anteil an P. (FOSSATI et al 2003, IMBERT u. LEFÈVRE 2003, TABBENER u. COTTRELL 2003, VANDEN BROECK et al 2006, so gibt es auch andere Untersuchungen, welche eben dieses gefunden hatten (AHRENS et al 1998, SMULDERS et al 2008a, ZIEGENHAGEN et al 2008. In diesen Studien wurde festgestellt, das eine enge räumliche Nachbarschaft von P. nigra und P. × canadensis wichtig für eine erfolgreiche Befruchtung ist.…”