Heterozygosity of wheat or rye genomes in triticale F1 hybrids: consequences for their cytological and agronomic behavior
1991
Martin, J. | Hesemann, C.U. (University of Hohenheim, (GERMANY). Institute of Genetics)
Four hexaploid primaries served for the production of triticale crosses. From the resulting genotypes, two with heterozygous wheat genomes and another two with heterozygous rye genomes were chosen for extensive cytological and agronomic investigations. The advanced inbred generations were observed up to F5. In F1 heterosis was meager, but in F2 heterotic effects were more evident, particularly in two genotypes. The degree of cytological aberrations drastically increased in F1 but diminished in further generations. Heterozygosity of the rye genome resulted in a significantly higher percentage of disturbed microspores compared with heterozygous wheat genomes. Agronomic characters were not affected in the same way, except for kernel shrivelling. This negative effect of F1 heterozygosity resulted in a delay of cytological stability even in advanced generations. As a result, heterotic effects which cover meiotic disturbances bear the risk of failure during selection of early generations. Moreover, the after effect of heterozygosity of the rye component may have consequences for selection and breeding strategies
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