Low level of genetic variation and signs of isolation in the native Hungarian sea buckthorn population compared to cultivated specimens

Abstract

Sea Buckthorn population from újpest Nature Reserve, the only one assumed to be native in Hungary sustains at the periphery of Budapest city on the sandy substrate deposited by the Danube river. The study aims to characterize the gene stock preserved on this small edaphic habitat by comparing with the genetic material of planted specimens of known origin used in horticultural and gardening practice. Fragment length variations of seven nuclear microsatellite markers were evaluated and a phylogenetic tree was constructed based on sequence variation of an intron from nuclear gene encoding the chalcone synthase enzyme. Gender rate was evaluated by female specific SCAR marker. Microsatellite analysis pointed out the extremely low variation of the natural sea buckthorn population from újpest Nature Reserve compared to the cultivated specimens, while the phylogenetic tree revealed that the natural population belongs to the genetic lineage distributed mostly in Western and Middle-Europe, and in Romania, region, which has strong links to the Balkan and the Black Sea. The analysis clearly separated the genetic material of the native újpest population from the planted individuals from the vicinity that proved to be of allochthonous origin. The HrX2 SCAR marker revealed the dominance of the males (1:1.42). The study provides support for the autochthonous origin of the Hungarian remnant population being in reproductive isolation that suggest for its long persistence and relict status. Ex situ conservation and nature protection measures are highly recommended to maintain one of the last native sea buckthorn populations of the Pannonian region.