The objectives of this proposal are: 1) conduct a field trial using the selected grapefruit seedlings to ensure the productivity of the trees in Florida where HLB is endemic; and 2) evaluate the quality of the fruit produced. Achievement of these goals will produce a more resistant/tolerant variety that could be available in the near future since its use would not require the regulatory approval. Based on two year’s graft-inoculation assays in greenhouse and the performance of individual seedlings in the field, four lines of the seedlings (with greater HLB resistance/tolerance) were selected for further propagation on three different rootstock (commercial sour orange, newly selected USDA-sour orange and 942). All these propagates (ca. 250 trees) are growing well in greenhouse, and expected to go to field next month. These propagates will be tested by qPCR before going to fields. The fruit quality (Brix, sucrose, glucose and fructose, soluble solids, pH, % TA and total ascorbic acid) of the four selected seedlings showed no significant difference from their maternal trees. New propagations of the selections from the the Scott grove seedlings, including 245 Red Ruby and 51 white Marsh plants on three different rootstock and 38 Red Ruby cuttings were planted in our research farm on Nov.15, 2017. Before going to field, samples were taken from these plants, and processed for qPCR detection. We will monitor the disease incidence and Las titers if there is an infection. Meanwhile we will go second round of selection and propagations on Scott seedlings, and then plant them in Scott grove for field evaluation. Because of the limitation of our greenhouse, and the new development of bud sport selection with several commercial grapefruit varieties such as Flame and Star Ruby. The propagation of the selected seedlings for Scott grove trial was delayed. However, another 80 trees generated from the cutting of the seedlings will be planted next week at USHRL Picos Research Farm for further evaluation. It is worth noting that some of the bud sport grapefruit plants showed less than 10% HLB affection rate after two years at USHRL Picos Farm with high disease pressure.