Locating QTL for Various Drought Tolerance Traits in Creeping Bentgrass.

Several physiological drought tolerance indicators have been identified in creeping bentgrass but have yet to be fully genetically characterized. Most are known to be controlled by multiple genes and therefore are quantitative traits. Identification of quantitative trait loci (QTLs) associated with drought tolerance would significantly improve the selection efficiency of drought-tolerant germplasm and varieties of creeping bentgrass. QTL analysis of phenotypic data collected from several drought studies in different environments (field, greenhouse, and growth chamber) and years was performed. Plants within the populations exhibited significant variation in drought symptom expression and tolerance traits when exposed to drought stress. QTL analysis was conducted on several phenotypic traits associated with drought tolerance (turf quality, electrolyte leakage, relative water content, water use efficiency, leaf area index, green leaf biomass, chlorophyll content, and osmotic adjustment). Minor and major QTLS will be discussed and the results indicate that some QTL markers associated with drought tolerance could be useful in marker-assisted selection of drought-tolerant turfgrasses.