Abstract: In order to study the crossability of wheat with H. bulbosum a series of wheat varieties from various sources and their F1 hybrids as well as tetraploid H. bulbosum from different countries were used as parents in this experiment. The main results of the experiment are showed as follows: 1. Twenty-one wheat varieties from Europe, West Asia, America, China, Australia etc. 11 countries and regions respectively as famele parents were crossed with four tetraploid H. bulbosum from Hungary, USSR, Canada and Germany. The seed set percentages in the intergeneric cross combinations ranged from 0.00% to 49.93%. Statistical analysis revealed that there were significant differences between the seed set percentages of wheat varieties. The crossability, with H. bulbosum might differed in different varieties of wheat from same country. 2. Various F1 hybrids resulting from 13 and 26 intervarietal cross combinations of wheat and their parents were crossed with H. bulbosum from Hungary and USSR respectively in different years. The mean seed set percentages of F1 hybrids, their male and female parents were 26.53%, 15.38%, 20.30% and 39.1%, 34.8%, 26.7% respectively. The results indicated that when some wheat varieties having poor-crossability with H. bulbosum were hybridized with other varieties especially with those varieties having high- crossability, the crossability of their F, hybrids probably had higher crossability than their parents having poor-crossability. Six F1 hybrids of wheat obtained from six com- binations of reciprocal crosses, in which the completely non-crossable varieties Hope, Xiao- Bai-Mang and high-crossable varieties Chinese Spring, Fortunate were used as male or female parent alternately, were crossed as female parents with H. bulbosum. All of 6 F1 hybrids were crossable and gave the percentage of seed set from 7.00% to 42.57%, although they ought to carry the dominant Kr genes responsible for non-crossability, which were passed on to F1 hybrids by non-crossable varieties, the parent Hope or Xiao-Bai- Mang. Clearly that is due to the gene interaction between female and male parents. Be- sides Kr loci in wheat, probably other genes can influence the crossability. 3. There were significant differences between clones of H. bulbosum in the crossa- bilities with wheat. In conclusion F1 hybrids of wheat have higher crossability with H. bulbosum than their parents having poor-crossability. This could be advantageous for exploitation of this technique. By selecting even more efficient clones of H. bulbosum and improving embryo culture techniques, the H. bulbosum technique will be used in wheat breeding program- mes probably.

Key words: Wheat, Barley, Horducm bulbosum, Crossability