Colonial Bentgrass Genetic Linkage Mapping and Identification of the Chromosomal Location of Genes Responsible for Dollar Spot Resistance.

Creeping bentgrass (Agrostis stolonifera L.) and colonial bentgrass (Agrostis capillaris L.) are important turfgrass species commonly used on golf courses.  Creeping bentgrass is highly susceptible to the fungal disease dollar spot (Sclerotinia homoeocarpa F.T. Bennett).  In contrast, colonial bentgrass has good resistance to dollar spot .  This study was conducted to determine if dollar spot resistance from colonial bentgrass could be introduced into creeping bentgrass.  A dollar spot resistant colonial bentgrass x creeping bentgrass interspecific hybrid was backcrossed with an unrelated creeping bentgrass plant and the resulting progeny were field tested for dollar spot resistance.  The results of the field test suggest that three colonial bentgrass genes may be required for the observed resistance.  Dollar spot resistance in colonial bentgrass is likely a qualitative trait and all three proposed genes may be required for resistance to dollar spot.  The backcross population was also used as a mapping population to generate the first genetic linkage map of colonial bentgrass.  The linkage map covers 1156 cM and consists of 212 AFLP markers and 110 gene-based markers.