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United States Department of Agriculture

Agricultural Research Service

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Location: Application Technology Research

2012 Annual Report

1a. Objectives (from AD-416):
Sustainability of the $4.22 billion commercial floriculture industry in the U.S. is being seriously challenged due to high energy costs. Considerable grower interest exists in producing winter and spring crops at lower temperatures to reduce heating costs. However, adoption of this practice may lengthen the production cycle thereby decreasing profits realized from growing at a lower temperature. We propose an efficient screening procedure to identify begonia accessions from a large germplasm pool that tolerate reduced temperature production. A well established preproduction screening procedure on seedlings or rooted cuttings will enable systematic evaluation of a larger number of plant accessions prior to conducting more expensive production evaluations with larger plants.

1b. Approach (from AD-416):
We will evaluate plants at plug stage (rooted cuttings or seedlings) for their physiological growth response at lower temperatures. Rooted cuttings, rather than seeds, are to be used for many accessions because in those accessions, seed propagation is slow. “Proof of concept will be developed in one or two accessions of begonia with multiple plants within each accession tested for replication. Begonia will be generated and provided by the Ornamental Plant Germplasm Center (OPGC) (Columbus, Ohio). The accessions Begonia cucullata and Begonia grandis will be tested since B. cucullata is the parent of many commercially important cultivars and B. grandis has been reported to have some tolerance for cold. At the conclusion of the study, all data will be entered into the USDA National Plant Germplasm System Germplasm Resources Information Network (GRIN) and be made publicly available. Small plants (plugs) of the two begonia accessions will be grown in a range of temperatures (3ºC increments, 3 steps, 15°C, 18°C, and 21°C) for a period of two to three weeks. This represents “normal” or recommended temperatures for greenhouse production for begonia, and 3ºC and 6ºC cooler than recommended. Photoperiod of the growing environment will be selected following a literature review to avoid its effects on flowering. After the two to three weeks time period, non-destructive measures of whole plant CO2 gas-exchange (photosynthesis and respiration), chlorophyll fluorescence, and number of leaves added during this period will be made at those growth temperatures.

3. Progress Report:
Following the devastating September 2010 tornado damage, we have made slow but steady effort to reestablish our research facility for the proposed project. We were able to repair the air handling system of the 12-chamber systems in the phytotron using the original equipment vendor’s service. The repair of electronics and data acquisition and control system of the phytotron facility, however, is a slow ongoing process. The systems were custom designed and it is taking a significantly long time to reestablish the system through the steps of system performance evaluation, trouble shooting, system repair, and system calibration. Realistically, we don’t think the 12-chamber system can be operational within a year for large scale replicated studies. We are confident, however, that the whole canopy gas exchange chambers can be fully functional by the end of 2012. The gas exchange chambers can then be used for limited plant samples as a proof of concept for the proposed high throughput characterization of Begonia species grown in lower temperature environments.

4. Accomplishments

Last Modified: 10/20/2017
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