1a.Objectives (from AD-416):
To determine mode of inheritance of beet curly top ("BCT") disease and conduct molecular genetic analysis using DNA markers using seed supplied by Cooperator SESVanderHave. To investigate BCT virus accumulation in populations using ELISA.
1b.Approach (from AD-416):
The cooperator will provide seeds for two sugar beet populations segregating for beet curly top. The ARS will grow the two populations in the greenhouse and individually inoculate the plants with viruliferous hoppers. The cooperator and ARS will collect leaf samples for DNA analysis and ELISA. The ARS and the cooperator’s scientist will collect phenotypic data. Data analysis will be conducted by both parties.
This agreement supports objectives 1 and 2 of the in-house project with the goal to evaluate segregating populations for beet curly top disease using three methods; phenotyping, DNA genotyping, and virus titer. Seed of two genetic mapping populations were planted in the greenhouse. At the appropriate growth stage the populations were inoculated artificially with the three curly top viruses using viruliferous beet hoppers (using clip-cage)from the Beet Sugar Development Foundation insectory. The populations were segregated for disease severity and visually evaluated by ARS scientists. The cooperator’s scientists visited the greenhouse and collected leaf samples for DNA genotyping and ARS scientists collected leaf samples for virus titer analysis. The phenotypic and virus titer data were provided to the cooperator. The ELISA and phenotypic data were analyzed and confirmed a correlation between greenhouse evaluation and virus titer. The results are beneficial to understanding inheritance and genetic mapping of the curly top resistance genes. The research objectives were fully met and the research was completed.