Project Number: 6034-21000-018-07-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Aug 1, 2016
End Date: Jul 31, 2021
Accelerate development of improved citrus scion cultivars.
Hybridizations will focus on creating new hybrids which capitalize on advanced United States Horticultural Research Lab selections, especially with huanglongbing-tolerance, as seed parents and Kishu-Hybrids as pollen parents. Mandarin, sweet orange-like and grapefruit-like progeny are targeted. We propose to capitalize on citron- and Microcitrus-derived huanglongbing-tolerance to develop Florida-adapted acid-fruits of commercial quality and introgress citron genetics into more mandarin and grapefruit-like hybrids. Germinate and grow seeds of 500 plus mandarin hybrids, 500 plus orange-like hybrids produced in 2015 crosses many of which will segregate for genetic seedless from using Kishu hybrids as pollen parents. Bud or graft trees into screenhouse/juvenility trellis as soon as possible. Irradiate buds of most-grapefruit-like hybrid selections showing some huanglongbing-tolerance, and grow trees for field planting. Continue screening existing hybrids at both the Ft. Pierce and Leesburg farms. There are thousands of hybrids planted over the last few years. Select buds of priority selections (irradiated and conventional hybrids) and pass through Department of Plant Industry's (DPI's) shoot-tip grafting program and establish material in the parent-tree screenhouse at U.S. Department of Agriculture Whitmore Farm as well as coordinating second tests in collaboration with New Varieties Development & Management Corporation (NVDMC) and another ARS scientist at the U.S. Horticulture Research Lab, Ft. Pierce. Establish and maintain priority seedlings on the juvenility trellis. Trees of each are also planted in the field to permit a first look at response to huanglnogbing, canker, alternaria, scab etc. Seek to accelerate movement through juvenility phase. In 2016-17, a major focus will continue to be evaluation of advanced hybrids in coordination with another scientist at the U.S. Horticulture Research Lab (USHRL), Ft. Pierce, Florida. Major replicated plantings of seedless/low seeded selections will be a focus. Working with New Varieties Development & Management Corporation (NVDMC) we will develop a more formal way of getting small numbers of diverse selections to a broader cross-section of the industry. Coordinating with New Varieties Development and Management Corporation (NVDMC), seedless/low seeded mandarin selections will be considered for early release to nurseries. To expedite identification of short-term huanglongbing solutions, cultivars will be identified in collaboration with industry, for field evaluation of huanglongbing-tolerance. In addition to fresh fruit types the processing industry will be asked to identify potentially huanglongbing-tolerant cultivars which may be combined to produce a satisfactory sweet-orange-like juice.