Characterization of wheat landraces for resistance to biotic and abiotic stresses

Abstract

This study covered genetic and molecular analyses of stripe rust and leaf rust resistance in common wheat landraces and investigation of response of drought and short term leaf temperature changes among a set of 20 durum wheat genotypes. Three all stage resistance genes (YrAW5 in Aus27430 and YrAW6 and YrAW7 in Aus27492) were identified. YrAW5 and YrAW7 were located on chromosomes 6AS and 5AL, respectively. The location of YrAW6 was inconclusive. While Aus27430 was concluded to carry Yr18, Aus27492 appears to carry an uncharacterized adult plant resistance gene. Four QTL for stripe rust resistance (QYr.sun-1BL, QYr.sun-2AL, QYr.sun-5AL and QYr.sun-3BS) were detected in Aus28166/AvS RIL population. QYr.sun-1BL and QYr.sun-5AL also conferred resistance to leaf rust in Aus28166. QYr.sun-1BL and QLr.sun-1BL corresponded to the pleiotropic locus Lr46/Yr29/Sr58/Pm39/Ltn. The co-located loci QYr.sun-5AL and QLr.sun-5AL appear to represent a new pleiotropic resistance locus. Durum wheat genotypes showed significant variation for mesophyll conductance in response to water stress and short-term variation of leaf temperature highlighting the potential for improving durum wheat for drought and heat stress.