ISHS Acta Horticulturae 396: Hydroponics and Transplant Production
EFFECT OF NEGATIVE DIF ON THE GROWTH AND PERFORMANCE OF GRAFTED TOMATO SEEDLINGS |
| Authors: | T. Ito, T. Maruo, M. Ishii, K. Suzuki, K. Matsuo, K. Kondo |
| Keywords: | Grafted-tomato, Negative DIF, Grafting, Acclimatization, Stem elongation |
| Abstract:
Grafted tomato seedlings were exposed to light/dark temperature of 20/30, 25/32 and 25/20 °C for 8 or 4 days in combination with two photoperiods of 8/16h and 10/14h under 2 levels of PPFD (267 and 467 μmol/m2/sec). Stem elongation was remarkably restricted by negative (-) DIF treatments. Negative DIF for 8 days decreased leaf area and chlorophyll content. Leaf number did not differ in -DIF and control treatments. Relative growth rate (RGR), net assimilation rate (NAR) and leaf area ratio (LAR) decreased slightly by -DIF treatment. Transpiration rate decreased considerably in the light period, and increased markedly during the dark in the -DIF plants. Carbon contents in the plant tissues decreased slightly in -DIF treatments. Nitrogen contents slightly increased during -DIF treatments, but decreased in control plants at the same period. Decreases in potassium content during 8 days were more remarkable in plants grown in the -DIF treatments. Dry weight showed no difference at 2 days after the end of treatments. Negative DIF plants recovered their transpiration rates in the light 2 days after the end of treatment and still maintaining considerably higher transpiration rates in the dark. | |
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