Location: Floral and Nursery Plants Research
Project Number: 8020-22000-052-001-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Sep 1, 2022
End Date: Aug 31, 2026
The overall objective of the proposed research is to develop sustainable rose systems based on cultivars resistant to Rose Rosette Disease (RRD) and black spot disease. The research will include work to: 1) Characterize the host plant interaction with the virus, vector mite and rootstock; 2) Develop adapted and commercially acceptable RRD and black spot-resistant roses; 3) Develop comprehensive research demonstration and education programs about RRD management; and 4) Assess the socioeconomic impact of RRD management approaches in four rose production systems. ARS Scientists will concentrate on the first objective, through the examination of sequence diversity between isolates of rose rosette virus (RRV), the causal agent of RRD; examination of the interactions between RRV and cultivars and breeding lines of roses having differential levels of resistance to RRD; determining the mechanisms of resistance to RRV infection or disease through effects on mite development, growth and fecundity; and use of various microscopy techniques to examine features of the host plant such as thickness of the epidermal layer, numbers and localization of feeding sites, and production of trichomes in response to RRV infection.
ARS scientists will perform full rose rosette virus genome amplification and sequencing of RRV isolates from evaluation sites and other locations to assess the extent of virus diversity, and interactions between RRV and other rose-infecting viruses. Genome segments of diverse RRV isolates predicted to differ biologically will be substituted into an infectious RRV system developed by a collaborating scientist at Texas A&M University, in order to evaluate effects on RRV pathogenicity, titer, and mite transmission, ARS scientists will also examine aspects of the biology of the eriophyid mite vector, including reproductive efficiency and longevity, movement, and environmental effects, to include differentiation of mite biotypes and differences in RRV transmission efficiency.