A test site for material proposed to have enhanced HLB resistance has been maintained at the USDA/ARS USHRL Picos Farm in Ft. Pierce, and has been open to requesting researchers for experimental plantings. As space is needed and experiments conclude, trees are pushed and replaced. Dr. Jude Grosser of UF has provided hundreds of transgenic citrus plants expressing genes expected to provide HLB/canker resistance, which have been planted in the test site. Dr. Grosser has planted an additional 100 tress including preinoculated trees of sweet orange on a complex tetraploid rootstock that appeared to confer HLB resistance in an earlier test. USHRL has a permit approved from APHIS to conduct field trials of their transgenic plants at this site, with several hundred transgenics in place. An MTA is in place to permit planting of Texas A&M transgenics produced by Erik Mirkov and he has trees expressing lectins under a USDA-ARS permit. Discussions have been ongoing with Eliezer Louzada of Texas A&M to plant his transgenics which have altered Ca metabolism to target canker, HLB and other diseases. Answers have been provided to numerous questions from regulators to facilitate field testing approval. APHIS BRS has visited the site on several occasions and confirmed that plantings are in compliance. We have provided permit details to assist plantings by other groups. A number of plants have been pushed as the analysis has been completed and new plantings made. A trial of more than 85 seedling populations from accessions of Citrus and citrus relatives (provided as seeds from the US National Clonal Germplasm Repository in Riverside, CA) has been underway for 7 years in the Picos Test Site. P. trifoliata, Microcitrus, and Eremocitrus are among the few genotypes in the citrus gene pool that continue to show substantial resistance to HLB (Ramadugu et al., 2016), and P. trifoliata also displayed reduced colonization by ACP (Westbrook et al., 2011). Tolerance to HLB was studied, with citron-derived material showing special promise within the genus Citrus (Miles et al., 2016). A new UF-Gmitter led association mapping study is nearing completion using the same planting, to identify genes associated with HLB- and ACP-resistance. A collaboration between UF, UCRiverside and ARS is well-underway with more than 1000 Poncirus-hybrid trees (including 100 citranges replicated) being evaluated to map genes for HLB/ACP resistance. Marked differences in initial HLB symptoms and Las titer were presented at the 2015 International HLB conference (Yu et. Al., 2015). David Hall led an effort to characterize ACP colonization and while pure Poncirus had much lower colonization, all citranges were intermediate between Citrus and Poncirus. Several USDA citrus hybrids/genotypes with Poncirus in the pedigree have fruit that approach commercial quality, were planted within the citrange site. Several of these USDA hybrids continue to grow well, with dense canopies and good fruit set, while sweet oranges are stunted with very low vigor (Stover et al., unpublished). A Fairchild x Fortune mapping population has been planted in a collaboration between UCR and ARS to identify genes associated with tolerance. This replicated planting includes a number of related hybrids (among them our easy peeling remarkably HLB-tolerant 5-51-2) and released cultivars. An additional trial, led by ARS Riverside is assessing HLB response in a broad array of Poncirus-derived accessions.