Date: Saturday, January 14, 2012
Time: 8:45 AM
Time: 8:45 AM
Room: Pacific Salon 3
Improvement of flavor and nutritional quality is an important objective in current strawberry breeding programs. QTLs and candidate genes have been identified for yield and related traits, and fruit quality characters evaluated during 3 years using ‘functional’ linkage maps of strawberry. 33 QTLs were identified for 14 different traits and approximately 37% of them were stable over time. 1-5 QTLs were detected per trait, with individual effects ranging from 9.2 to 30.5% of the phenotypic variation. Candidate genes for QTLs controlling different traits were identified based in their co-location and predicted function. In addition, syntenic QTLs among strawberry and other Rosaceae are proposed. Besides sugars, acids and texture, strawberry flavor is determined by a complex balance of aroma compounds. More than 300 volatile compounds were detected by HS-SPME-GC-MS in the population and 87 of them were identified. Cluster analysis grouped the volatiles into distinct chemically related families and revealed a complex metabolic network underlying volatile production in strawberry fruit. Seventy QTLs covering 48 different volatiles were detected, with several of them being stable over time and mapped as major QTLs. Using a candidate gene approach we have assigned genes that are likely responsible for several of the QTLs. As a proof of concept we show that one homoeolog of FaOMT is the locus responsible for the natural variability of mesifurane content. Sequence analysis identified a polymorphism in the promoter of this FaOMT homoeolog that fully co-segregates with both the presence of mesifurane and the high expression of FaOMT during ripening.