Wednesday, November 7, 2007 - 11:15 AM
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Comparative Genome Analysis of Snow Mold Resistance and Winter Hardiness in Creeping Bentgrass.

Geunhwa Jung, 206 French Hall, University of Massachusetts, University of Massachusets, Dept. of Plant, Soil, & Insect Sciences, Amherst, MA 01003, Young-Ki Jo, Plant, Soil, and Insect Sciences, Unversity of Massachusetts, 230 Stockbridge Road, Amherst, MA 01003, Michael Casler, USDA-ARS, USDA/ARS U.S. Dairy Forage Res.Ctr., 1925 Linden Drive West, Madison, WI 53706-1108, and Suleiman Bughrara, Michigan State University, Dept. of Crop & Soil Sciences, 488 Plant & Soil Sci. Msu, East Lansing, MI 48824-1325.

Snow molds caused by Typhula spp. are the most economically important winter diseases of turfgrass in the northern and alpine regions of the United States and Canada. During winter, these psychrophilic pathogens take advantage of the weakened host plants at low temperatures under persistent snow cover. Snow molds significantly decrease turf quality and delay turf recovery. Fungicide application in fall is only option to have acceptable control of the disease. The most environmentally sound strategy for managing snow molds is breeding for disease resistance. However, genetics information on snow molds resistance in turfgrass is limited. Therefore, QTL mapping experiment was conducted to estimate location, number and effect of QTL for snow mold field resistances in creeping bentgrass (Agrostis stolonifera). To meet this objective, a full sib mapping population (549 x 372) of creeping bentgrass previously used for QTL mapping of dollar spot resistance was planted at two different locations in Michigan and Wisconsin and was evaluated for snow mold severity and recovery in 2004 and 2005. Snow mold resistance was inherited quantitatively. Fourteen QTLs for snow mold resistance and recovery were identified on nine out of 14 linkage groups (LGs). We detected a genomic region on LG5 contained QTL for snow mold resistance over two locations for two years and also found some QTL dependent on location or year. Through comparative approach, the LG5 QTL appeared to be in syntenic region where QTLs for cold tolerance in ryegrass were previously detected. A cluster of C-repeat binding factor (CBF)/dehydration-responsive element-binding protein 1 (DREB1) previously mapped in perennial ryegrass was also in the syntenic region. Markers tightly linked to snow mold resistance QTLs can be very useful for marker-assisted selection in future creeping bentgrass breeding programs.