Aim 1 assesses inter-annual phenotypic variation in a common scion (‘Chambourcin’) by growing it ungrafted and grafted to three different rootstocks (‘1103P,’ ’3309C,’ and ’SO4’) in an experimental vineyard at The University of Missouri Southwest Center Agricultural Experiment Station in Mount Vernon, MO. The scion ‘Chambourcin’ is one of the top five Missouri cultivars, and the rootstocks ’1103P,’ ’3309C,’ and ’SO4’ are derived from commonly used North American species in rootstock breeding (V. rupestris x V. berlandii, V. rupestris x V. riparia, and V. riparia x V. berlandii, respectively.) Check out the slideshow (below) for photos of the vineyard and fieldwork progress.
This aim quantifies the extent to which shoot system phenotypes vary as a function of rootstock, including the effect of irrigation on root-shoot communication and the inter-annual variability of graft-transmissible phenotypes. We will test how water availability influences the modulation of scion phenotypes by the rootstock, and how rootstock-modulated scion phenotypic variation is stable over the course of three years. The full factorial experiment with varied rootstock and irrigation regimes includes 288 vines. Leaf and berry tissue are collected from the plants at different phenological stages (50% anthesis, veraison, and harvest) throughout Years 1-3. Measurements taken include estimates of vegetative growth, leaf shape, ion concentration, gene expression, vine physiology, leaf metabolomics, and berry chemistry. We are also sampling a subset of 60 plants for RNA-seq analysis.