Early root and aboveground biomass development of hybrid poplars (Populus spp.) under drought conditions

Currently, the genus Populus is one of the favourite objects for research of molecular genetics of woody plants. A high growth rate and the broadly applicable timber as raw material for different types of products made of wood make poplar attractive for industrial usage. Despite the positive aspect of its growth capacity and wood composition, one major problem in cultivating fast-growing tree species in a forestry plantation system is the comparably high water demand of the plants. In this context, a rapid development of an efficient adventitious root system from dormant hardwood cuttings is an essential requirement for the successful establishment of short-rotation cultures. It reduces the establishment costs of plantations, and the developing plant can be transferred into favourable conditions due to varying environmental conditions. Results of greenhouse pot and soil-column experiments on the development of shoots and adventitious roots from hardwood cuttings of seven hybrid poplar cultivars and the reaction of the plants performance on varying water availability will be presented. We estimated root and shoot length, root and shoot growth and biomass accumulation over time, root-to-shoot length ratio, and root morphological traits.