Development, selection and characterization of summer patch (Magnaporthe poae Landschoot and Jackson) resistant somaclones of Kentucky bluegrass (Poa pratensis L.) genotypes
To develop a somatic embryogenic system for Kentucky bluegrass, crowns, embryo axes, leaf, and endosperm tissues of twelve genotypes were cultured on Murashige and Skoog medium containing various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP). Callus induction and shoot regeneration varied significantly by genotype and type of explant. In all genotypes leaf and endosperm tissues were recalcitrant. Embryo axes and crown pieces regenerated an average of two shoots per culture on medium containing 0.3 mg/l 2,4-D and 0.2 mg/l BAP. The effects of growth regulators and dark incubation on regeneration of cultured explants were studied using two genotypes. Increasing the concentration of 2,4-D and BAP to 0.6 mg/l and 0.3 mg/l, respectively, plus incubating the cultured explants for three weeks, significantly increased both somatic embryogenesis (from 29% to $\ge$90%) and the average number of shoots per culture regenerated (from 2 to $\ge$5). Regenerated plants varied in growth characteristics, chlorophyll pigmentation, resistance to powdery mildew (Erysiphe graminis), and summer patch (Magnaporthe poae). Variants highly resistant to powdery mildew and summer patch were selected, and the resistance was expressed through several cycles of vegetative propagation. There was no relationship between resistance to summer patch and that of powdery mildew.
Biology, Cell, Agriculture, Plant Culture, Agriculture, Plant Pathology
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign