Introgression of Asian soybean rust resistant genes into elite soybean lines from Uruguay

Soybean is the main agricultural crop in Uruguay. One of the diseases with the greatest damage potential is Asian soybean rust, with estimated grain yield losses up 80% in the region. Throughout history, different authors have stated the importance of genetic resistance as a fundamental tool to decrease the adverse effects of phytopathogens, leading to agriculture sustainability. The objective of this work was to introduce rust resistance genes into elite lines of INIA’s soybean breeding program and to evaluate the enhanced resistance. Introgression of resistant genes was carried out in a greenhouse, through three backcrosses from F1. Two donors: Py7-1-47 and No6-12-B handed by JIRCAS with two resistant genes combinations (Rpp1-b + Rpp5 and Rpp4 + Rpp5, respectively) and three elite lines: SJ10-122-040, SJ10-158-039, and SJ10-173-072 from INIA’s breeding program were used. After each backcross, plants carrying both genes were selected with marker assisted selection. Each third backcross was self-pollinated (BC3F2) and single plant families were inoculated in the greenhouse. Percentage of rust resistant plants within the introgressed families ranged from 42% to 98%, compared to fully susceptible recurrent parents.