II. 9. Haploids from barley x rye crosses.
G. Fedak, Research Branch, Agricultural Canada, Ottawa, Ontario, Canada.
As a plant breeder, one cannot help but be impressed by some outstanding characteristics in rye, such as a high level of winterhardiness, straw strength, and outcrossing habit. The barley crop could be greatly improved with the incorporation of any of these factors to any degree. The pollination of barley, H. vulgare L. (2n=14) by rye, S. cereale L. (2n=14) results in a surprisingly high seed set; in the order of 30%. Unfortunately, this is not accompanied by embryo development. In the initial attempts, embryo sacs were dissected from 400 seeds, three hundred of which contained only water sacs in the place of embryos. The remaining 100 embryo sacs contained tiny undifferentiated spheres, all of which were cultivated on an artificial medium. Four embryos grew to produce haploids of barley. Preliminary observations indicated that the rye chromatin was selectively and sequentially eliminated through fragmentation at mitotic divisions as previously has been reported for the bulbosum technique. There are some indications that amount of seed set in barley following pollination by rye was cultivar specific, so that strains may be found in the two species that will hybridize.