2012 Annual Report
1a.Objectives (from AD-416):
Our contribution to this proposal is in pehnotyping powdery mildew resistance and fruit quality traits in 4 breeding populations in order to develop markers linked with resistance and fruit quality loci.
1b.Approach (from AD-416):
(1) Phenotype the parents and progeny of four powdery mildew resistant families (maintained in Parlier field) for resistance segregation.
(2) Phenotype parents and progeny of the same four powdery mildew resistant families for segregation of fruit traits.
The agreement was established in support of Objective 2A, of the in house project, the goal being to evaluate existing table grape and raisin populations for powdery mildew (PM) resistance and select vines that combine host-plant resistance with high fruit quality.
This research contributes to development, maintenance and phenotyping of PM resistant grape seedling populations. This project also provides support for evaluation of seedlings and advanced selections with SSR markers for PM resistance and fruit traits. This will build confidence in the use of marker assisted selection.
Leaf tissue from four populations created at Parlier, Califoornia, that combine Vitis (V). vinifera with V. cinerea, V. romanetii, V aestivalis, and V. rotundifolia has been provided to Cornell University genotyping center to determining their genetic makeup by sequencing. Characterizing PM resistance and fruit quality traits for these four populations will begin in July and continue through the summer at Parlier, California. Leaves from 95 plants of the V. vinifera x V. aestivalis population have been provided to the Cornell University phenotyping center for determination of PM resistance. Over 900 PM and red flesh grape seedlings and selections have been developed at Parlier, California. Leaf tissue samples from these 900 individuals were sent to Cornell University genotyping center to verify SSR molecular markers used to aid selection of plants with desirable traits.