Tuesday, November 6, 2007 - 2:30 PM
168-7
Identification of Quantitative Trait Loci (QTL) Associated with Drought Tolerance in Creeping Bentgrass.
Loss of turf quality due to limited water availability is a major concern in turfgrass management. Therefore, there is an urgent need to develop turfgrasses that are able to provide high quality turf with limited irrigation. Several different drought tolerance mechanisms have been identified that are utilized by turfgrasses but have yet to be fully genetically characterized. Most drought tolerance traits are known to be controlled by multiple genes; thus, identification of QTLs associated with drought tolerance would improve the selection efficiency of drought-tolerant germplasm and varieties. The objectives of this study were 1) to evaluate genetic variations in drought tolerance of a mapping population of bentgrass; and 2) identify QTL markers associated with drought tolerance in creeping bentgrass. The mapping population with both parents (‘L-93’ and 7418-3) and 102 F2 progenies varied significantly in physiological parameters, leaf relative water content (RWC), and osmotic adjustment (OA), when exposed to drought stress under greenhouse conditions. QTL analysis was conducted on the phenotypic traits associated with drought tolerance (electrolyte leakage, relative water content, and osmotic adjustment) evaluated in the controlled environment study in one mapping population. Two QTLs associated with electrolyte leakage, three QTLs associated with relative water content, and one QTL associated with osmotic adjustment were identified. The results indicate that some QTL markers associated with drought tolerance could be useful in marker-assisted selection of drought-tolerant turfgrass.
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