Development of Next Generation Rootstocks for California Vineyards

We are making strong progress in streamlining the assay’s for nematode, salt and phylloxera screening to test new germplasm, existing breeding populations to single out best rootstock selections, and test breeding and mapping populations. We have dynamic duo of Becky Wheeler and post-doc Daniel Pap to greatly accelerate nematode screening efforts. We have built up inoculum to carry out germplasm screening for the dagger nematode. Salt screening of germplasm that was promising in earlier screens was initiated at higher concentrations (75mM) to select optimum accessions that we could use in crosses. At the same time, we are initiating salt screening of breeding populations with different accessions of V. longii and 140Ru to look for segregation in order to carry out marker development process. We are making good progress in better understanding of root architecture in multiple rootstock species including Vitis berlandieri. The key point from different drought screens is that specific root length and root diameter is key features that could be used to test rootstock selections. Trials of selected accessions that pass the screening for horticultural features, nematode, phylloxera and salt tolerance are in pipeline for 2018-2019 funding cycle.