Role of Cell Wall Degrading Enzymes in Interaction of Poplar and Melampsora laricipopulina Poplar rust resistance study A NUMERICAL TAXONOMIC STUDY OF POPLAR RUSTS(MELAMPSORA SPP.) ANALYSIS OF THE GENETIC SPECIALIZATION OF MELAMPSORA LARICI-POPULINA WITH RAPD MARKERS Dynamic Changes of Active Oxygen and Related Enzymes of the Host in Interaction between the Poplar and Melampsora larici-populina A New Species of Melampsora CYTOLOGICAL STUDIES ON THE HOST-PATHOGEN RELATIONSHIP IN THE COURSE OF POPLAR LEAF INFECTION BY MELAMPSORA LARICI-POPULINA Morphology of uredospores and infecting structure of Melampsora pruinosae in Populus euphratica and P. pruinosa Identification of a Rust Fungus on Populus alba Collected in Jilin, China and Its Spermogonial and Aecial Stages HISTOPATHOLOGY STUDIES ON INTERACTION OF POPLARS AND LEAF RUST WITH DIFFERENT COMPATIBILITIES