2019-10_18-039C_Grosser_PR.pdf – Part B The UF/CREC-Citrus Improvement Program’s Field Trial Evaluations

Part B - The UF/CREC-Citrus Improvement Program's Field Trial Evaluations (Complementary to Part A- the UF/CREC Core Citrus Improvement Program)

Report Date: 01/02/2020
Project: 18-039C   Year: 2019
Category: Plant Improvement
Author: Jude Grosser
Sponsor: Citrus Research and Development Foundation, Inc.

Significant progress has been made with additions to our website, presenting data from our field trials. Data from the 6 trials listed blow has been entered onto the website during this quarter. Website access: https://citrusresearch.ifas.ufl.edu/rootstock-trials/
Trial # Online Title Location – County Date planted
11 Vero Beach Navel Orange and Grapefruit Roostock Trials Indian River 2010
12 Charlotte County Multi-Scion Rootstock Trial Charlotte 2014
13 LaBelle Valencia APS Roostock Trial Hendry 2009-2010
14 LaBelle ‘Vernia’ Roostock Trial Hendry 2010
15 South Ridge Valencia Rootstock Trial Highlands 2014
16 St. Helena Rootstock Survey Trial Polk 2008 & 2010

Seed fruit was harvested from UFR rootstocks and a few other promising rootstock selections including the gauntlet selection A+VolkxOrange19-11-8, and the seed was extracted and treated by Southern Citrus Nurseries. UFR seed will be distributed to participating nurseries. Seed from Cleo+Carrizo was also extracted, and will be used in experiments in efforts to solve the granulation problem in Seedless Snack and the granulation/low brix problem in Florida navels.

Vegetative material of promising gauntlet rootstocks S10xS15-12-25, 8-1-99-2B X C-22-12-11 and LB8-9xS13-15-16 (the first gauntlet rootstock made with SugarBelle as a parent) was provided to Agromillora and the Phillip Rucks Nursery Tissue Culture laboratory for tissue culture initiation. Another promising selection recovered from Balm (non-gauntlet) 2247 x 2075-02-7 was also provided. Seed trees are not available for any of these rootstocks. The ‘S’ designations in the above parentages indicate salt tolerant parents, as rootstock hybrids stacked with abiotic stress genes continue to perform exceptionally well in the HLB screen. Four other candidates available from the DPI Parent Tree Program were also made available to the TC companies; these include A+HBJL-2B (tetraploid sour orange-type), Blue 1, White 1 and Cleo+Carrizo. Seed was also extracted from several Flying Dragon hybrids (and planted for advanced trials, these have potential for tree size control).

The first trees were planted in our new PTS (Parent Tree Structure), where we will keep superior breeding parents (both diploid and tetraploids) free of HLB and other diseases; guaranteeing their availability for future crosses.

Field Planting at the USDA Picos Farm: 150 new gauntlet rootstock selections were planted (grafted with HLB+Valencia); these include 40 new hybrids made with SugarBelle LB8-9, and many of them also include one of the salt tolerant parents (S10: HB Pummelo x Shekwasha; and S13: HB Pummelo x Cleopatra).

Your browser does not support pdfs, click here to download the file.