Characterization of different provenances of Slavonian pedunculate oaks (Quercus robur L.) in Münsterland (Germany) with chloroplast DNA markers: PCR-RFLPs and chloroplast microsatellites

Abstract

Late flushing pedunculate oaks ("slawonische Stieleiche"; Quercus robur L.) have been introduced into Germany especially in the region around Munster (Munsterland) in the second half of the 19(th) century from the lowlands of the rivers Save and Drava between Zagreb and Belgrade. They are characterized by comparatively late bud burst but also by accelerated growth and a sparsely ramnified and upright stem. We analysed twelve selected oak stands in the Munsterland approved for the harvest of forest reproductive material at chloroplast DNA markers. The analysed material included one indigenous stand and eleven stands of late flushing Slavonian oaks that have been established in the Munsterland at the end of the 19th century according to historic documents. In total, we distinguished five genetic variants (haplotypes) by PCR-RFLP of chloroplast DNA (cpPCR-RFLPs) and four by chloroplast microsatellites (cpSSRs). Four out of these haplotypes represent nearly all haplotypes (haplotype 2, 5, 7-26, 17) so far observed in Croatia. The fifth haplotype (haplotype 1) was found in all samples of the indigenous oak stand but also in low frequencies (about 10%) in four out of eleven Slavonian stands. Haplotype I has a center of distribution in Central Europe; it is predominant in the Munsterland but absent from the Balkan region. Since the analysed cpDNA markers show predominant or fixed haplotypes within stands and discriminate between stands, they are useful for the identification of adult trees and reproductive material of Slavonian oak stands in Germany. The haplotype composition in the stands of the Munsterland is in accordance with their origin in the lowlands of the rivers Save an Drava. In total five informative cpSSR markers are described. Marker ucd4 is sufficient to distinguish unambiguously between the indigenous and Slavonian haplotypes. With this fast and reliable marker system is will be possible to identify chloroplast haplotypes in a high-throughput assay. In order to obtain appropriate tools for the identification of reproductive material of Slavonian oaks we plan to characterize all well-known Slavonian oak stands in North-Rhine Westphalia (Germany) at cpDNA markers.