Development and identification of new syntheticT. turgidum–T. monococcumamphiploids

Abstract

AbstractTriticum monococcumssp.monococcumhas useful traits for bread wheat improvement. The synthesis ofTriticum turgidum–T. monococcumamphiploids is an essential step for transferring genes fromT. monococcuminto bread wheat. In this study, 264 wide hybridization combinations were done by crossing 60T. turgidumlines belonging to five subspecies with 83T. monococcumaccessions. Without embryo rescue and hormone treatment, from the 10,810 florets pollinated, 1983 seeds were obtained, with a mean crossability of 18.34% (range 0–89.29%). Many hybrid seeds (90.73%, 923/1017) could germinate and produce plants. A total of 56 new amphiploids (AABBAmAm) were produced by colchicine treatment ofT. turgidum×T. monococcumF1hybrids. The chromosome constitution of amphiploids was characterized by fluorescencein situhybridization using oligonucleotides probes with different chromosome and sub-chromosome specificities. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis indicated that theGlu-A1m-b,Glu-A1m-c,Glu-A1m-dandGlu-A1m-hproteins ofT. monococcumwere expressed in some amphiploids. Despite resistance reduction in several cases, 45 out of 56 amphiploids exhibited resistance to the current predominant Chinese stripe rust races at both the seedling and adult plant stage. These novel amphiploids provide new germplasm for the potential improvement of bread wheat quality and stripe rust resistance.