COMPARISON OF THE CROSSABILITY OF RYE (<i>SECALE CEREALE</i>) AND <i>HORDEUM BULBOSUM</i> ONTO WHEAT (<i>TRITICUM AESTIVUM</i>)

Abstract

Fifty-six wheat (Triticum aestivum L.) lines representing a wide diversity of germplasm were screened for crossability with rye. Seed set values ranged from 0.0% to 95.4% of the florets pollinated. Twenty-eight of these wheat lines representing the range of crossability with rye were then pollinated with tetraploid Hardeum bulbosum L. Seed set ranged from 0.0% to 32.2%. Those wheats giving seed set with H. bulbosum generally had medium to high crossability with rye. A high correlation (r = 0.75) was obtained for crossability of rye and H. bulbosum on wheat, indicating that the main genetic system (Kr 1 and Kr 2 ) governing crossability with rye is also the main system operating in crosses with H. bulbosum. Evidence for additional factors influencing crossability and for differences between rye and H. bulbosum is provided. Hybrids between wheats having different crossability levels exhibited intermediate crossability levels with rye but very low crossability with H. bulbosum. Hordeum bulbosum genotypes differ in their ability to effect seed set.