EVALUATION OF DONOR ABILITIES OF DURUM WHEAT IMMUNE INTROGRESSIVE LINES DERIVED FROM <i>TRITICUM TIMOPHEEVII</i> ZHUK
The evaluation of the donor abilities of stem rust resistant durum wheat lines created by hybridization of Triticum durum Desf. with T. timopheevii Zhuk. has been carried out. Two introgressive immune lines (HT-7, HT-10) were studied. They have been tested in the experimental field under artificial inoculation of plants at tillering stage with a set of the most aggressive stem rust races from the local populations in Western Siberia for many years. To determine their donor abilities, the lines were crossed with four durum wheat varieties. F<sub>1</sub>BC<sub>1</sub> - F<sub>3</sub>BC<sub>1</sub>, F<sub>1</sub>BC<sub>2</sub> - F<sub>3</sub>BC<sub>2</sub> as well as F<sub>2 </sub>progenies were investigated. Resistance to stem rust of introgressive tetraploid lines derived from T. timopheevii can be transferred to the offspring both in self-pollination hybrids and in backcrossing programmes. Each additional backcrossing requires increasing several times a sample size due to polygenic control of resistance to stem rust. The observed and expected frequencies of immune recombinants were approximately equal when they were infected with one race and a set of pathogen races. This fact gives reason to use the results of genetic analysis in a breeding programme to create immune wheat varieties. The introgressive lines could be considered as donors of stem rust resistance in breeding for immunity.