TY JOUR TI Production technology of the planting material of the poplar grades which is turning gray by In Vitro method for creation of plantation crop KW varieties of poplar KW technology in vitro KW planting material KW specialized plantations JO Actual directions of scientific researches of the XXI century: theory and practice AU Sivolapov, A.. AU Tabatskaya, T.M. AU Mashkina, O.. AU Sivolapov, V.A. PY 2014 IS 2 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov