Triticale - results and problems
Hybrids between wheat and rye were first produced and described. During the period 1918 to 1934 Meister and coworkers in Saratov in Russia, were active in the field of wheat-rye hybridization. A large number of spontaneous hybrids were all male-sterile but "balanced hybrids", intermediate between wheat and rye, were later observed and found to be fertile and true breeding. They were therefore suspected to be a new polyploid species. During the period 1929-1931 this was verified who found that the fertile hybrids had 56 chromosomes and thus were amphiploids of bread wheat and rye. They also observed irregularities at meiosis caused by the presence of univalent chromosomes. Bread wheat is a typical selffertilizer and consequently homozygous and true-breeding. In most cases cultivated rye is a heterozygous wind pollinated crossfertilizer with a special incompatibility mechanism. As triticales are mainly selffertilizing like wheat, the rye component in a primary triticale becomes homozygous immediately. Since the great majority of inbred lines of rye die before reaching the inbreeding minimum, it is somewhat surprising that triticales can be produced at all. Evidently, however, the two or three wheat genomes are strong enough to make the alloploid triticale viable, and by means of crosses and other measures more balanced and vigorous amphiploids can be obtained. The wheat genomes also suddenly and strikingly influence the rye component in another way.