Grant Information

DEVELOPMENT OF HUANGLONGBING RESISTANT/TOLERANT CITRUS THROUGH GENOMIC APPROACHES

Sponsoring Institution Agricultural Research Service/USDA
Status ACTIVE
Funding Source USDA INHOUSE
Reporting Frequency Annual
Project Director ROSSKOPF E N
Accession Number 435031
Project Number 6034-21000-019-003R
Dates 2019-06-01 - 2024-05-31
Recipient Organization AGRICULTURAL RESEARCH SERVICE
219 SOUTH ROCK ROAD
FT PIERCE,FL 34945
Keywords asiaticus
breeding
candidatus
citrus
genetics
greening
huanglongbing
liberibacter
resistance
tolerance
Research Effort Applied (30%)
Basic (70%)
Developmental (0%)
Classification Parameters
Knowledge AreaSubject of InvestigationField of SciencePercent
203 - Plant Biological Efficiency and Abiotic Stresses Affecting Plants 920 - Orange 1000 - Biochemistry and biophysics 50%
204 - Plant Product Quality and Utility (Preharvest) 999 - Citrus, general/other 1080 - Genetics (excludes breeding) 50%
Goals / Objectives

Through traditional breeding, we have generated populations of novel citrus hybrids with Huanglongbing (HLB) resistant Australian citrus parentage. The hybrids segregating for resistance traits will be used for association of genetic markers with disease resistance. Candidate genes identified as valuable will be used to transform elite citrus cultivars to incorporate resistance traits. Specific objectives are:

  1. to generate reference sequences of three HLB resistant citrus relative species
  2. identification of genetic differences between resistant and susceptible hybrids by low depth whole genome sequencing of 100 hybrid lines
  3. transcriptome study of selected individuals

Combination of these techniques will enable identification of candidate genes associated with resistance.

Methods (unparsed)

Genes conferring HLB resistance/tolerance will be identified in citrus relative genera and incorporated into commercial citrus types. We have already generated hybrid populations exhibiting a range of phenotypes from complete HLB resistance to tolerance and susceptibility. The resistant parents have now been in the field for ten years in Florida, and the resistant hybrids are under continued monitoring for over two years after HLB challenges in the greenhouses. We propose using genomic tools to identify disease resistance genes from these hybrids and transfer these genes into cultivated citrus through biotechnology methods.

Methods
Genes conferring HLB resistance/tolerance will be identified in citrus relative genera and incorporated into commercial citrus types. We have already generated hybrid populations exhibiting a range of phenotypes from complete HLB resistance to tolerance and susceptibility. The resistant parents have now been in the field for ten years in Florida, and the resistant hybrids are under continued monitoring for over two years after HLB challenges in the greenhouses. We propose using genomic tools to identify disease resistance genes from these hybrids and transfer these genes into cultivated citrus through biotechnology methods.