Genetical studies on a Tibetan semi-wild wheat, Triticum aestivum ssp. tibetanum.

A semi-wild wheat, Triticum aestivum ssp. tibetanum, collected in Tibet and taxonomically classified by Shao et al. (1980), was investigated for its phylogenetic relationship to common wheat. Ssp. tibetanum is a hexaploid spelt wheat showing wedge-type disarticulation of the ear, and it is assumed to be somewhat unstable genetically. F1 hybrids between ssp. tibetanum and other common wheats are fully fertile in both sexes, although three interchanges exist between them. The haploid genotype for hybrid necrosis and hybrid chlorosis is ne1ne2ch1ch2; the Ch2 allele, common in both Aegilops squarrosa and common wheat, including Chinese cultivars, is missing. The chloroplast genome is similar, and the mitochondrial genome is only slightly different from their counterparts in common wheats. Its cytoplasm does not induce male sterility in the all common wheat genotypes studied. These facts suggest that it is an offtype of Tibetan common wheat.