European European Regional Development fund agreement No. 2014/0025/2DP/2.1.1.1.0/14/APIA/VIAA/101
Salix species are fast growing trees or shrubs which readily hybridize, and are easily vegetatively propagated via root cuttings because of the high auxin content in willow bark, which makes these species suitable for rapid breeding processes. Poplars, like willows, can also be efficiently vegetatively propagated, which can be utilized in breeding programs. Many clones have been selected in breeding programs, but only some of them are actively used for biomass and timber production. Many of them are protected by plant variety rights, which increases their price and makes them less attractive to customers. Local germplasm is already adapted to the climatic and other growing conditions within a region or country, and therefore crosses between selected local and highly productive introduced clones could improve the productivity of local germplasm, while also retaining locally adapted traits. On the other hand, demand for raw material, harvesting and processing technologies are rapidly changing, and in recent years, the ecosystem services provided by tree plantations are increasingly valued, which is influencing the selection parameters used in breeding programs. Researchers at the LSFRI "Silava" have identified local willow germplasm for multifunctional utilization, which would be advantageous for commercialization in the limited market in Latvia and the Baltic states. Two clones of Salix burjatica Nasarow – 'Visvaldis' (male, registration No. 20133297) and 'Monika' (female, registration No. 20130683) – were selected from roadside ditches, pretested and registered in the Community Plant Variety Office (CPVO). Both clones have high rooting capacity, bright decorative shoots, very good regrowth after harvesting, their flowers are attractive to bees and other pollinators, and the twigs could be used for furniture making and other handicrafts. Both clones have medium yield and are suitable for mechanized harvesting with 'Bioballer type' machines. The hybrid poplar clone 'Auce' (P0114) Populus × woobstii (R. I. Schröd. ex Regel) Dode (registration No. 20142267) was initially planted in Latvia at the end of the last century and had good growth results (4.2–9.8 t of dry matter per year in both forest and agricultural conditions), and was approved as forest reproductive material in Latvia and registered in the CPVO, and tested for homogeneity.
The willow and poplar clones have been genetically fingerprinted using simple sequence repeat (SSR) markers in the Genetic Resource Centre laboratory of LSFRI "Silava" to enable rapid and unambiguous identification of these clones.