Grant Information

HIGH-THROUGHPUT INOCULATION OF CITRUS GERMPLASM FOR HLB RESISTANCE SCREENING

Sponsoring Institution Agricultural Research Service/USDA
Status ACTIVE
Funding Source USDA INHOUSE
Reporting Frequency Annual
Project Director STOVER E W
Accession Number 435976
Project Number 6034-22320-007-006R
Dates 2019-01-01 - 2021-12-31
Recipient Organization AGRICULTURAL RESEARCH SERVICE
219 SOUTH ROCK ROAD
FT PIERCE,FL 34945
Keywords asian
citri
citrus
diaphorina
greening
huanglongbing
liberibacter
plant
psyllid
resistance
Research Effort Applied (30%)
Basic (45%)
Developmental (25%)
Classification Parameters
Knowledge AreaSubject of InvestigationField of SciencePercent
211 - Insects, Mites, and Other Arthropods Affecting Plants 910 - Grapefruit 1040 - Molecular biology 40%
215 - Biological Control of Pests Affecting Plants 920 - Orange 1130 - Entomology and acarology 40%
211 - Insects, Mites, and Other Arthropods Affecting Plants 1131 - Wine grapes 1130 - Entomology and acarology 10%
216 - Integrated Pest Management Systems 1130 - Table grapes 1040 - Molecular biology 10%
Goals / Objectives
  1. To inoculate new transgenic and conventional citrus developed for huanglongbing (HLB) tolerance or resistance.
  2. Support other projects targeting Asian citrus psyllid (ACP), Candidatus Liberibacer asiaticus (Clas) or vector and host relations by providing (as available) to researchers psyllids infected by the huanglongbing (HLB) pathogen.
Methods (unparsed)

The basic huanglongbing (HLB) inoculation program is as follows. Psyllids for inoculations are obtained from psyllid colonies maintained on HLB-affected citrus in cages. Each cage of infected psyllids is considered a colony, and these colonies are regularly assessed to verify they contain infected psyllids, to estimate percentages of psyllids infected, and to assess levels of Candidatus Liberibacter asiaticus (CLas) present using quantitative polymerase chain reaction (qPCR) analyses. We maintain up to individual colonies in walk-in environmental chambers). To screen citrus for resistance to HLB, plants replicated for individual transgenic events or other genotypes of interest are caged individually and 20 psyllids from an infected colony are introduced into each cage. Multiple replicated sets of control plants are included in each trial to provide a baseline for identifying resistant types. The caged plants are maintained in one of two laboratories under ambient conditions beneath LED illumination (14 hours). After two weeks, the cages are removed and the plants are transferred to the breeders to be monitored for the disease and disease resistance/tolerance. The plants are transplanted to larger pots and moved to a psyllid-free hoop house to be evaluated for growth, HLB-symptoms and titer of the HLB pathogen. Eventually the trees are transplanted to the field for continued assessments.