Aim 3 gauges genotype x environment interactions by examining vegetative, reproductive, physiological, and transcriptomic traits of a single grapevine scion ‘Marquette’ grafted onto a segregating rootstock mapping population.
The unique ability to clone and graft grapevine allows us to perfectly replicate the mapping population and place them in four variant environments: experimental vineyards in Mount Vernon, Missouri, Geneva, New York, Brookings, South Dakota, and Parlier, California (see left.)
For Aim 3 we will conduct a multi-site QTL mapping study to detect and resolve additive genetic (G) and environmental (E) effects, as well as their interaction (GxE). This study will strictly isolate and measure the genetic basis and environmental sensitivity of graft-transmissible phenotypes originating from roots.
We generated a F1 mapping population (‘V. rupestris B38’ x ‘V. riparia HP-1’), and clonally propagated its young plants, producing a core set of 200 rootstock genotypes. These rootstocks will be grafted with ‘Marquette’ and grown for one year at Forrest Keeling Nursery in Elsberry, MO, prior to planting at each of the four vineyards (image, top left). The rootstock genotypes will also be grown own-rooted, for comparison.
Phenotypic measurements will be taken in subsequent years for a subsample of the rootstock/scion populations in addition to tissue collection for gene expression analysis.
Please see the photo collection below to follow the growth and progress of our grafted grapevines.