GRAIN YIELD AND YELLOW RUST RESISTANCE IN POPULATIONS OF WHEAT OBTAINED BY SELECTION

Abstract

The purpose of this work was to evaluate the grain yield losses caused by yellow rust (Puccinia striiformis f. sp. tritici), as well as to evaluate the effectiveness of the recurrent visual selection to produce high yield and high resistance to yellow rust genotypes. The cycles C₀ to C₇ of recurrent visual selection generated by application of the MSFRS (Male Sterile Facilited Recurrent Selection) methodology alternated at Chapingo, México (Summer) and Roque, Guanajuato (Winter) during the 1992 to 1997 were evaluated. In the Autumn - Winter 1998-99 cycle four experiments were carried out in two planting dates (December 1 and 16): two of such experiments were conducted under yellow rust infection and the other two were yellow rust free by chemical treatment. The later yielded 30 % more than the treatment without protection. When considering the best five families of each selection cycle, it was observed that those families with highest grain yield were also the most susceptible to yellow rust; however, when considering the 240 families included in the study, it was possible to detect varieties with besth high yield potential and resistant to yellow rust.