EVALUATING RYE INBRED LINES PER SE AND IN EUPLASMIC AND ALLOPLASMIC CROSSES FOR TRITICALE SUITABILITY

The production of primary triticales (x Triticosecale Wittmack) is lab orious and the performance of the resulting amphidiploids has been mos tly unsatisfactory. It is, therefore, desirable to have criteria to as sess wheat and rye lines as suitable triticale parents. This study inv estigated the genotypic variation and covariation caused by 15 rye (Se cale cereale L.) inbred lines per se and as parents of testcrosses, eu plasmic and alloplasmic (Triticum turgidum L. and T. aestivum L. cytop lasm) rye F2 populations, and hexaploid and octoploid primary tritical es in order to assess rye lines for their ''triticale suitability.'' A ll materials were evaluated in drilled yield trials at two locations a nd in 2 yr. Genotypic variances between rye lines were generally great er than those due to rye parents in testcrosses, F2 populations, and p rimary triticales. The variances of hexaploid and octoploid triticales , when significant, were of similar magnitude. Correlations between th e two ploidy levels were moderate to high for all traits. Relationship s between triticales and corresponding rye materials were inconsistent and frequently negative for yield and yield component traits. The pre diction of triticale performance based on rye line and cross performan ce was possible for days to heading, but was without prospect for the yield complex. Rye lines which proved favorable as parents of hexaploi d triticales were superior at the octoploid level as well.