Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 10/4/2018
Publication Date: 11/24/2018
Citation: Lin, H., Nwugo, C.C., Shi, X. 2018. Screening and identification of Pierce’s disease and powdery mildew dual resistance grapevines from an advanced back cross breeding population. CDFA Pierce's Disease Control Program Research Symposium. p. 137.
Technical Abstract: A backcross (BC) made in 2015 combined Pierce's disease (PD) resistance PdR1 from V. arizonica with powdery mildew (PM) resistance from V. romanetii. This advanced BC population was derived from BC3 population (F8909-08 x b42-26) previously developed by USDA-ARS. Seeds were obtained and germinated; of those, 120 seedlings were grown in a greenhouse. Pathogenicity tests identified 46 resistant progeny with no foliar PM symptoms, while 44 progeny showed severe PM symptoms. Thirty plants were moderately susceptible to PM. Dormant cuttings have been prepared from 46 PM-resistant progeny for PD resistance screening. To further identify the molecular basis of dual resistance, a genotyping by sequence approach has been implemented to facilitate mapping resistance loci linked to resistant traits.