Dr. James J. Luby

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    100 Years of Fruit Crops Breeding at the University of Minnesota
    (Department of Horticultural Science, University of Minnesota, 2009) Luby, James
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    Evaluation of Avena sativa L./A. fatua L. crosses
    (1982) Luby, James J.
    The use of micronuclei frequency/microspore quartet (MF) has been proposed to indicate relative reduction in chromosome homology among interspecific oat (Avena L.) hybrids. Hybrids with lower MF presumably undergo greater genetic recombination, providing greater opportunity for breaking linkages contributing to association, or coherence, of desirable and undesirable characters in progenies. Progeny lines from eight A. sativa L./A. fatua L. crosses were evaluated with parents and check cultivars to determine whether A. fatua might contribute useful variation for improving agronomic and grain quality characters in cultivated oats and whether a relationship exists between MF and character coherence. Differential emergence among progeny lines due to seed dormancy accounted for some variability in grain yield in 1980. In 1981, five crosses had population means for grain yield equal to their A. sativa parents. All crosses contained lines that equalled or exceeded A. sativa parents or check cultivars for grain yield. High groat oil in A. fatua parents and progenies indicated A. fatua could be used to increase oil levels in cultivated oats. Though parents did not differ from groat protein all crosses had variation among lines, indicating fatua may have different genes than A. sativa. Progeny lines with dark seed color or shattering habit were higher for harvest index, earlier, shorter, and lower in groat oil, groat protein and groat percentage than light-colored or nonshattering lines. Character coherence was examined in progenies from four A. sativa/L. fatua hybrids with high MF and four hybrids with low MF. The degree of coherence of seed disarticulation and color with quantitative traits that distinguish the parental species was not related to differences in MF among these crosses. Likewise, the degree of coherence among the quantitative characters studied, as measured by coefficients of concordance, was not associated with differences in MF among the crosses. The analyses used could detect only character coherence and not genetic recombination, per se. Accurate genotypic measurements of characters controlled by genes on potentially abnormally pairing chromosomes are necessary to determine a relationship of MF with recombination and character coherence.