The genetics and gliadin protein characteristics of a wheat–alien translocation that confers resistance to colonization by the wheat curl mite
The wheat curl mite (Eriophyes tulipae Keifer) is the vector of both wheat streak mosaic virus and the wheat spot mosaic agent, which cause damaging diseases of wheat (Triticum aestivum). A spontaneous translocation between chromosome 6A of the hard spring wheat cultivar 'Cadet' and a group 6 chromosome (6Ag) from decaploid Agropyron elongatum (Host) Beauv. resulted in a transfer of resistance to colonization by the wheat curl mite from 6Ag to a wheat chromosome. Transmission of resistance was 50.2% through the egg and 28.2% through the pollen. In segregating progenies, 64.1% of the plants were resistant, and 25.5% of the resistant plants were homozygous resistant. Meiotic pairing of hybrids from crosses between the translocation line and ditelocentrics for chromosome 6A suggested that the translocated chromosome consisted of the short arm of 'Cadet' 6A and the p or short arm of chromosome 6Ag of A. elongatum that confers mite resistance. This postulation was confirmed by electrophoretic patterns of seed endosperm proteins; the translocation line produced α-gliadins coded by genes on the short arm of 'Cadet' 6A as well as β-gliadins coded by genes on the short arm of A. elongatum chromosome 6.Key words: electrophoresis, gliadins, wheat streak mosaic virus, Agropyron elongatum, Robertsonian translocation.