The crossabilities of wheat varieties with Hordeum bulbosum

Abstract

Two experiments to investigate the crossabilities of varieties of bread wheat, Triticum aestivum, with Hordeum bulbosum are described. In the first a range of varieties having low and high crossability with rye, Secale cereale, were used. It was found that a strong positive correlation between the crossabilities of wheat varieties with H. bulbosum and with rye exists. In the second experiment the genetics of crossability was investigated using chromosome substitution lines of the non-crossable variety, Hope, into the cross-able variety Chinese Spring. Two chromosomes, namely 5A and 5B of Hope, were found to reduce markedly the crossability of Chinese Spring. These chromosomes were those identified by Riley and Chapman (1967) as being responsible for the crossability of Chinese Spring with rye, reinforcing the conclusion that the crossability of wheat with both species is governed, at least in part, by the same genetic system. However, other chromosomes were also shown to affect the crossability of Chinese Spring, although to a much lesser extent. The use of this interspecific cross to produce wheat dihaploid lines for breeding purposes is discussed.