Evaluation of reliable sampling tissue and seasonality for consistent detection of CLas by qPCR
Principal Investigator Affiliation:
Central California Tristeza Eradication Agency
- Lucita Kumagai
- Raymond Yokomi
Cryptic infection, low titer and uneven distribution of CLas in the tree is a major hurdle in selecting the best sample for early detection. Regulatory testing of CLas by qPCR stipulates sampling of one-season-old mature leaves. Such leaves are good for visual inspection of HLB symptoms, but can be unreliable tissue for early detection. Phloem-limited plant pathogens move in a source-to-sink fashion along with photoassimilates. Identifying the reliable sink tissue matched with its ideal season is critical for early detection. Citrus Pest Detection Program would implement the collection of appropriate sink-tissue for large-scale HLB survey in commercial settings. Testing the right tissue sample at the right time of the year would help in confirming the suspect trees identified by indirect EDTs.