Temperature-sensitive adult plant leaf rust resistance in bread wheat (triticum aestivum L.)

Abstract

Temperature sensitivity of the adult plant resistance shown by 16 bread wheat lines against race 77-5 of Puccinia recondita (the most common and virulent) on the Indian sub-continent was studied. The infection types on these 16 lines were also compared with those of the known adult plant resistance genes Lr12, Lr13, Lr22a, Lr22b, Lr34 and Lr37. Frontana, CIM25 (a leaf-rust resistant breeding line), Pavon 76, Pari 73 and Flinders carried lowtemperature adult plant resistance (LTAP) which was expressed only at 14.5°C. The adult plant resistance of Chris, Arz, Mukta, WW15(R) and VL421 was best expressed at 30°C, and these 5 wheats carried high temperature adult plant resistance (HTAP). The adult plant resistance of WH291 was expressed equally at 14.5, 20 and 30°C. The infection pattern of Mentana, WL410, IWP72, HD2204 and Son-Kl-Rend was similar to that of Thatcher near-isogenic lines carrying the genes Lr22a and Lr37 and their adult plant resistance was expressed only at 20°C. The Thatcher near-isogenic lines carrying the genes Lr12, Lr13, Lr22b and Lr34, and WL711 having the gene Lr13 did not show resistance against race 77-5.