A new system of transfer of genetic information from Hordeum to Triticum

The efficiency of a tetraploid hybrid from H. bulbosum x H. vulgare as the pollinator in hybridization with varieties from T. aestivum (5), T. turgidum (3), triticale (2) and S. cereale (1) was tested. The chromosomal constitutions of the hybrid genotypes were revealed by 11 isoenzyme markers (ER, AAT, EST, NDH, PGM, MDH, PER, 6-PGDH, LAP, NAD-AADH, and NADP-AADH) of all 7 barley chromosomes (without distinguishability between H. bulbosum and H. vulgare) and cytologically studied by checking the chromosome number in mitosis and meiosis. Hybrid plant production of pollinated florets (in percent) ranged from 0.0 (triticale and rye) to 27.0 (7o. aestivum). Incomplete elimination of barley chromosomes occurred in crosses with T. aestivum. The degree of elimination varied with the wheat genotype and accounted for up to a maximum of 30 % of produced hybrid plants. The other plants were eu- or hypohaploid wheats (e.g., lacking chromosome 1B or 3A). Isoenzyme analysis of plants of the first backcross generation with wheat marked, in single plants, the meiotic transmission of added barley chromosomes from primary hybrids. Usability of this system of crossing the tetraploid H. bulbosum X H. vulgare hybrid with wheat is discussed with regard to genetic introgression and haploid production in wheat.