Using SSR markers to understand the mechanism of powdery mildew disease resistance in Cornus florida
M. Mmbaga (1), L. PARIKH (2). (1) Tennessee State University School of Agriculture & Consumer Science, McMinnville, TN, U.S.A.; (2) Tennessee State University, Nashville, TN, U.S.A.
Powdery mildew is one of the most devastating diseases in nursery production of flowering dogwoods <i>C. florida</i> across the Southern U.S. Effective fungicides for powdery mildew control have been identified; however, routine applications required for effective control have increased production costs and forced small growers out of dogwood production. While efforts in powdery mildew resistance breeding are being taken, only a few cultivars have displayed an acceptable level of powdery mildew resistance; understanding the underlying mechanism of powdery mildew resistance will facilitate breeding strategies. The aim of this research project was to study the inheritance of the powdery mildew resistance in previously selected powdery mildew resistant plant (R14) that has consistently exhibited resistance at multiple locations. Controlled crosses from hand pollination were carried out between susceptible (Cherokee Princess) and resistant selection (R14). Progeny seedlings were exposed to powdery mildew and rated for disease reaction, but only a few plants out of hundreds displayed powdery mildew resistance. Genome wide analysis of the parents and the progeny was done using Simple Sequence Repeat markers (SSR’s). The polymorphism pattern was studied in an effort to identify markers that are linked with powdery mildew resistance. Results from this study will facilitate marker assisted breeding (MAB) in flowering dogwood.
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