EVALUATION OF HLB/ACP RESISTANCE IN PONCIRUS TRIFOLIATA HYBRIDS AND ASSESSMENT OF DNA MARKERS AND POSSIBLE RESISTANCE GENES
Subtropical Insects and Horticulture Research
2013 Annual Report
1a.Objectives (from AD-416):
Evaluate array of Poncirus hybrids and standard cultivars to ultimately identify which genes are associated for use in conventional and transgenic plant improvement.
1b.Approach (from AD-416):
Plant replicated trial with 8 plants of each of numerous citranges (from a well-characterized mapping population), other poncirus hybrids and standard cultivars. Material will be at USDA/ARS Picos Farm where HLB and ACP are rampant and will be screened in response to natural exposure.
This project is related to Objective 1: Create new genetic combinations of citrus, Objective 2: Screen germplasm for important traits and select superior individuals, Sub objective 1 D: Create new scions and rootstocks with potential resistance to huanglongbing (HLB) and citrus bacterial canker (CBC) by genetic transformation.
More than 120 citranges, from a well-characterized mapping population, and other trifoliate hybrids (+ sweet orange standards) have been planted in a replicated trial in collaboration with University of Florida and University of California/Riverside. Plants are being monitored for Liberibacter development and HLB symptoms. A USDA/ARS advanced selection which is 1/16th Poncirus, with commercial quality fruit, is performing extremely well. Data from this trial should provide information on markers and perhaps genes associated with huanglongbing (HLB) resistance, for use in transgenic and conventional breeding. The University of California-Riverside has genotyped these plants by sequencing.