Location: Application Technology Research Unit
Project Number: 5082-21000-015-28
Start Date: Sep 29, 2010
End Date: Jul 31, 2013
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.