Influence of Growing Temperature on Dry Matter Accumulation in Plant Parts of ^|^lsquo;Siberia^|^rsquo; Oriental Hybrid Lily

Abstract

Abstract'Siberia' Oriental hybrid lily plants were grown under conditions of changing day temperature (DT) and night temperature (NT). Plants were grown under three fluctuating temperature conditions (average 25.8°C, 23.4°C, and 19.9°C) in a temperature gradient growth chamber (TGC), and under three DT/NT levels (28/23°C, 24/19°C, and 20/15°C) in constant temperature growth chambers (CGCs). In the CGC experiment, 35 days after planting (at the visible bud stage), the plants grown under low temperature conditions had high fresh weight (FW) of the stem and stem roots. At the flowering stage in both TGC and CGC experiments, the plants grown under low temperature conditions had a longer stem length and higher FW of the stem, flower buds, stem roots, and bulb compared than those of plants grown under high temperature conditions. The plants grown under low temperature conditions had high dry weight (DW) of the total plant, stem, and bulb, and a high DW/FW ratio of the stem and bulb. In both TGC and CGC experiments, the plants grown under the low temperature conditions showed a high relative growth rate (RGR) and net assimilation rate (NAR) from planting to flowering. These data demonstrate that cooler growing temperatures are advantageous for the accumulation of dry matter in 'Siberia' lilies. The low growing temperature enhances the accumulation of dry matter in 'Siberia' lily plants via the promotion of photosynthesis by leaves and the absorption of nutrients by well-developed stem roots.

The Effects of Day and Night Temperature on the Dry Matter Accumulation of Oriental Hybrid Lily ‘Siberia’ as they Relate to the Photosynthetic and Respiratory Characteristics

“…Compared to the data in the present experiments, in which DT and NT changed independently, 'Siberia' lily plants that were grown under three DT/NT combinations of 28/23°C, 24/19°C, and 20/15°C showed great differences in DM accumulation at flowering in our previous experiment (Inamoto et al 2013). This result suggests that the positive effects on DM accumulation by promoting photosynthesis at low DT and suppressing dark respiration at low NT are additive.…”

“…4A). Inhibited root development was observed under the combination of high DT and NT in our previous report (Inamoto et al 2013). Still, the high DT condition of 28°C in Experiment 2 may have caused some development and/or functional disorder of the roots that affected the absorption of water and mineral nutrition.…”

“…These experiments indicated that leaf photosynthesis was effective for DM accumulation after the visible flower bud stage during 'Siberia' lily growth. Moreover, we previously grew 'Siberia' lily plants under different combinations of day temperatures (DTs) and night temperatures (NTs) that were changed simultaneously, and found that combinations of low DT and NT promoted DM accumulation and improved the quality of cut flowers (Inamoto et al 2013). It is conceivable that DT and NT significantly affect photosynthesis and dark respiration, respectively.…”

Effect of CO₂ Enrichment on the Photosynthesis and Dry Matter Accumulation in the Oriental Hybrid Lily ‘Siberia’

“…From the DW and LA data, we calculated the leaf area ratio (LAR, LA per unit of total plant DW, cm 2 •g −1 ), leaf mass per area (LMA, leaf DW per LA), relative growth rate (RGR, rate of increase in total plant DW per unit of plant DW, mg•g −1 •d −1 ), and net assimilation rate (NAR, rate of increase in total plant DW per unit of LA, g•m −2 •d −1 ), as described in our previous reports (Inamoto et al, 2013(Inamoto et al, , 2015(Inamoto et al, , 2016.…”

“…In tulips, we found that the duration of cold treatment of mother bulbs affected the competitive partitioning of dry matter between shoots (equivalent to cut flowers) and daughter bulblets at flowering, and significantly affected the quality of cut flowers. Next, we applied growth analysis as previously applied to other ornamental plants such as rose (Ushio et al, 2008) and tulip (Inamoto et al, 2000a), and as we applied to lily (Inamoto et al, 2013(Inamoto et al, , 2015(Inamoto et al, , 2016, to clarify the relationship between photosynthetic efficiency and CO 2 enrichment.…”