The general goal of this project is to rapidly propagate complex citrus rootstock material for field testing. The rootstock materials to be tested will be products of the Citrus Improvement Program at the UF-IFAS-CREC in Lake Alfred. Specifically, these materials will be selected based upon their performance in the �HLB gauntlet�: Promising rootstock genotypes will have already been evaluated in the greenhouse and field for their ability to grow-off citrus scions that have been exposed to CLas-positive budwood and CLas-positive Asian citrus psyllids. Once candidate rootstock materials have successfully passed through this gauntlet, they will be propagated via rooted cuttings en masse in a psyllid-free greenhouse at the UF-IFAS-IRREC in Fort Pierce. From there, rootstock materials will be budded with scion materials and planted in the field for further testing for their long-term performance. The original PI of this project Dr. Gruber has resigned, so Co-PI Dr. Jude Grosser is assuming responsibility for completing the project. Ms. Amy Dubois is the OPS assistant taking care of the trees at the IRREC, she will continue in this roll. All of the recovered cuttings and seedlings were evaluated and the inventories of liners that could make a good field tree are provided below. These will be grown to grafting size, grafted with selected scions (including a dark red grapefruit somaclone N11-15 showing possible tolerance/resistance to HLB) and planted in IR field trials. Viable cutting inventory: Rootstock # of liners recovered 1. A+HBPxCH+50-7-12-14 44 2. 46×31-00-S10x46x31-00-S11-S5 78 3. Orange 10 x Green 7-11-1 52 4. A+VolkxOrange19-11-5 90 5. A+HBJL2BxOrange14-09-7 71 6. A+HBJL2BxOrange19-09-31 14 7. A+HBJL1-09-14 25 8. A+FDxOrange19-11-11 50 Viable seedling inventory: 1. 46×20-04-S22 86 2. 46×20-04-42 94 3. 46×20-04-48 78 4. 46×20-04-S13 86