Selection of clones of Populus nigra L. ssp. nigra for resistance to Melampsora larici-populina Kleb. Rust

Abstract

A possibility of selection of clones of the species Populus nigra L. with higher resistance to the rust Melampsora larici-populina Kleb. was tested in a set of 29 clones of P. nigra originating from individuals selected in various localities of the CR. Clones were tested in three localities for four years. Rust infection was evaluated according to a five-point scale. The two most resistant (R<sub>1</sub>; R<sub>2</sub>) and two most sensitive (S<sub>1</sub>; S<sub>2</sub>) clones were tested in laboratory conditions. The results of this test confirmed to be consistent with those obtained under field conditions. Significant differences between the progenies of resistant (R<sub>1</sub> × R<sub>2</sub>) and sensitive (S<sub>1</sub> × S<sub>2</sub>) parents proved the genetic control of resistance. Intermediate inheritance of resistance was found in the progenies S<sub>1</sub> × R<sub>2</sub> and R<sub>1</sub> × S<sub>2</sub>. Genetic effect of the paternal component was also expressed. A possibility of selection for resistance to M. larici-populina rust in P. nigra was proved.