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United States Department of Agriculture

Agricultural Research Service

Research Project: Conservation, Characterization, and Genetic Improvement of Subtropical and Tropical Ornamental Germplasm

Location: Subtropical Horticulture Research

2013 Annual Report


1a.Objectives (from AD-416):
1. Conserving tropical/subtropical ornamental crop genetic resourses and associated information important for the evaluation and utilization of that material.

2. Development and application of new or improved horticultural evaluation procedures and genetic marker-based approaches for genetic diversity assessment of the preceding genetic resources.

3. Genetic improvement efforts directed to developing new, superior tropical/subtropical ornamental germplasm.

4. Transfer of technology in the form of tropical/subtropical ormamental crop genetic resourses, associated information, and new, superior tropical/subtropical ornamental germplasm to researchers and breeders worldwide.

5. Evaluate containerized subtropical/tropical ornamental germplasm for its growth responses to different container media components. Where feasible, estimate for this germplasm the heritabilities and other patterns of genetic variation for adaptation/tolerance to the different container media components.


1b.Approach (from AD-416):
Collect new accessions of subtropical/tropical ornamental plants that have commerical potential in the U.S. Evaluate newly collected accessions and existing material, primarily flowering trees and shrubs already on site, using phenotypic characters and molecular makers. Organize the information such that it can be used as descriptors for inclusion in the GRIN system. Utilize the molecular and phenotypical analysis to breed improved germplasm in support of the ornamental industry. Communicate and coordinate subtropical/tropical ornamental horticultural research with local and regional industry, universites, and foreign germplasm effort in Florida, Puerto Rico, and Hawaii.


3.Progress Report:
All population of Zamia from Bahamas, Cayman Islands and Florida have been genotyped with 30 microsatellite loci. The only Zamia sample collections remaining to be made are from Cuba and collaborators are travelling there in July 2013. Sequencing of a subset of each population with 10 single copy genes has been completed for the Bahamas and Florida. ARS plant patent committee has approved patent for five amaryllis hybrids and patent applications are being prepared. We have begun an experiment to determine the best concentration and exposure duration of oryzalin for effective chromosome doubling in amaryllis. Sequences of five single copy genes were used in phylogenetic analysis of the entire order Cycadales. Preliminary data show that forms of nitrogen including ammonia (NH4NO3 or (NH4)2SO4) resulted in the best growth of Zamia pumila. Nitrate-N as the sole nitrogen source and organic nitrogen improved growth over plants receiving no nitrogen. Coralloid root development was poor in all treatments. Seed from Zamia floridana were collected and a second study is planned to confirm these results.


Last Modified: 9/20/2014
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