The effect of wheat cytoplasm on the synthesis of wheat x rye hybrids.

Four nuclear genotypes of Triticum aestivum L., each substituted into the cytoplasm of T. timococcum Kostoff, Aegilops ventricosa Tausch and T. timopheevi Zhuk., were crossed with four homozygous Secale cereale L. inbred lines to produce 48 alloplasmic octoploid primary triticales. Crossability, embryo differentiation, amphihaploid plantlet recovery in vitro, and response to colchicine treatment were investigated. It was found that in general the effects of the wheat cytoplasm on the characteristics studied were of equal importance as those of the wheat and the rye nuclear genotypes. Cytoplasm can be regarded as an additional source of variation in the synthesis of primary triticales. Cross-compatibility in wheat x rye hybrids appeared to be determined by specific parental genotypes and their nucleo-cytoplasmic interactions rather than by any general compatibility of particular nuclear genotypes and/or cytoplasms.