Location: Grape Genetics Research
Title: QTL analysis of fruit cluster abundance in grape (Vitis sp.) Authors
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 17, 2014
Publication Date: N/A
Interpretive Summary: Maximizing yields of grapevines is of major importance to grape growers and grape breeders. In this study, one major yield component was studied with an experimental genetic population. The specific traits that were evaluated were the number of clusters per shoot, and whether or not the particular vines produced fruit clusters in greater numbers than is typical for a grape shoot. The results were that there was one specific region of the genome that was consistently associated with the number of fruit clusters per shoot of grapevines within this population. Also, a different genetic region was associated with the ability of a vine to produce fruit clusters further along the shoot than is typical for most grapes. This information will be useful in understanding the genetics for yield variation in grape and assisting in the breeding of higher yielding grape vines.
Technical Abstract: Sustainably maximizing yield or productivity of fruit over time is a major goal of modern viticulture. One major yield component is the number of fruit or flower clusters present on a single shoot of the current year’s growth. A quantitative trail loci (QTL) study was conducted on both average number of fruiting clusters per shoot and for the presence/absence of adventitious cluster development beyond those normally produced at the basal nodes of the current season’s shoots in a segregating population of 190 seedlings derived from a cross between an inter-specific hybrid grape (‘St Pepin’) and a wine grape (‘Cabernet franc’). One QTL was identified on chromosome 7 for average clusters per shoot that explained 12.1% and 12.5 % of the phenotypic variation in two separate growing seasons. Also, a single genetic locus was identified on chromosome 2 that was significantly associated with the presence of adventitious cluster formation. The prospects are discussed for the potential interest in use of these results for marker-assisted selection for cluster abundance.