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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Research Project #425023

Research Project: Genetic Improvement of Prunus and Vitis Scions and Rootstocks for Fruit Quality and Pest Resistance

Location: Crop Diseases, Pests and Genetics Research

Project Number: 2034-21220-006-000-D
Project Type: In-House Appropriated

Start Date: Jun 14, 2013
End Date: May 8, 2018

The overall goal of the proposed research is the development and introduction of new high quality and disease resistant cultivars of almonds, grapes and stone fruits that will sustain American agriculture and supply high quality, nutritious fruits and nuts to US consumers and international markets. This goal was validated, and ranked as a high-priority ‘researchable objective’ by stakeholders attending the 2011 Program Visioning Conference held at the San Joaquin Valley Agricultural Sciences Center. Specifically, over the next five years we will focus on the following objectives: Objective 1: Evaluate table and raisin grape germplasm with putative resistance to powdery mildew for superior fruit quality and field resistance to powdery mildew under commercial conditions. Objective 2: Evaluate fruit quality of dry-on-vine (DOV) raisin selections and of “teinturier” type table and raisin selections. Objective 3: Develop superior Prunus rootstocks with resistance to economically important soilborne pests and excellent graft compatibility, desirable scion vigor, and excellent production potential. Objective 4: Select and evaluate new high quality scion cultivars of Prunus (almond, apricot, peach, and plum) from currently available breeding crosses.

Classical breeding techniques have been used to create segregating populations where the expression of quantitative traits has been concentrated and newly available characters have been transferred into adapted Prunus and Vitis germplasm. Seedlings in existing segregating populations of Prunus and Vitis will be selected and propagated for new cultivar development. Greenhouse and field screening will proceed to select Vitis seedlings with resistant to powdery mildew. Molecular markers will be used to identify those Vitis seedlings with multiple sources of powdery mildew resistance. Resistance to powdery mildew and Pierce’s Disease will be combined through hybridization of appropriate vines. Hybridizations will continue for production of both dry on the vine and red flesh color in grapes. Apricots will be selected for drying ability and for late maturity season from all remaining segregating progenies. New self-compatible almonds will be selected from segregating populations that have kernel qualities similar to Nonpareil, and four high kernel quality self-compatible almond selections will be trialed in three locations in the San Joaquin Valley. Hybridization will be repeated if necessary, to achieve population sizes necessary for identifying and selecting elite germplasm or for the development of molecular markers linked to traits of interest.