systems are closed to pathogens and their vectors. In addition, the growing of transplants in CTPS could further reduce the use of pesticides after transplantation through the improvement of plant resistance to pathogens by illumination with artificial
Toshio Shibuya, Kaori Itagaki, Motoaki Tojo, Ryosuke Endo, and Yoshiaki Kitaya
L. Zhang, J.R. Livingstone, Y. Tarui, and E. Hirasawa
, is a good model for experiments performed with artificial illumination. Materials and methods ‘Italian Red’ hibiscus plants were purchased from J Flowers (Shinsaibashi, Osaka, Japan). They were maintained indoors from 22 July to 31 Dec. 2003 in a room
Victor Rodov, Shimshon Ben-Yehoshua, Jong Jin Kim, Boris Shapiro, and Yitzhak Ittah
Ultraviolet (UV) illumination (254 nm) induced production of the phytoalexin scoparone in flavedo of kumquat (Fortunella margarita Lour. Swingle cv. Nagami) and orange [Citrus sinensis (L.) Osbeck cvs. Shamouti and Valencia]. Trace amounts of scoparone (<2.0 μg·g-1 fresh weight of flavedo) were detected in nontreated fruits. Phytoalexin accumulation in kumquat reached a peak of 530 μg·g-1 11 days after illumination, hut the amount declined rapidly, returning to a trace level 1 month after treatment.. Production of scoparone in illuminated fruits was enhanced by increasing the UV dose from 1.5 × 103 to 9.0 × 103 J·m-2 for orange and from 0.2 × 103 to 1.5 × 103 J·m-2 for kumquat and by raising the storage temperature from 2 to 17C. Phytoalexin accumulation correlated with an increase in antifungal activity of flavedo extracts. UV-illuminated kumquat fruit inoculated with Penicillium digitatum Sacc. 2 days after treatment had a lower incidence of decay than the control. Illumination of previously inoculated fruit failed to prevent decay. Kumquat fruit stored at 17C showed signs of UV-induced peel damage. Chemical name used: 6,7-dimethoxycoumarin (scoparone).
Chieri Kubota and Mark Kroggel
Increasing numbers of greenhouse vegetable growers purchase transplants from specialized transplant propagators. Possible deterioration of transplants during transportation limits the market size as well as the potential sources of high-quality transplants. To determine the best conditions for transportation of seedlings, tomato (Lycopersicon esculentum Mill., cv. Durinta) seedlings with visible flower trusses were placed for 4 days inside growth chambers to evaluate the effects of short-term exposure to different air temperatures (6, 13, or a conventional transportation temperature of 19 °C) under darkness or illumination at 12 μmol·m–2·s–1 PPF. Plants were evaluated for visual quality, photosynthetic ability, growth, and fruit yield. Lower temperatures and illumination significantly maintained visual quality of the seedlings. Lower temperature maintained high photosynthetic ability of seedlings during the 4-day treatment. After transplanting in the greenhouse, a significant number of trusses exhibited flower abortion or delayed fruit development when seedlings were treated at 19 °C regardless of light intensity. Results suggested that 6 to 13 °C was the best transportation temperature for up to 4 days, which was later validated by an actual transportation trial between British Columbia and Arizona.
Zunfu Lv, Simeng Zhang, and Guoquan Lu
content, and light regulation had a positive effect on the DPPH clearance rate. With increasing anthocyanin content, the DPPH clearance rate also rose. According to the correlation analysis, a lower light intensity and shorter illumination time will result
Raymond A. Cloyd, Amy Dickinson, Richard A. Larson, and Karen A. Marley
illumination or a combination of these factors, which may influence insect response to light. In addition, insect attraction may be the result of the type of light source (e.g., mercury vapor, incandescent, fluorescent, or ultraviolet lamps). As a result, it
Toshio Shibuya, Ryoko Terakura, Yoshiaki Kitaya, and Makoto Kiyota
Application of a low-relative-humidity treatment (LHT) to seedlings can reduce water stress on cuttings harvested from the seedlings, after the cuttings are planted. Effects of illumination during LHT and LHT duration on leaf water potential and leaf conductance in cucumber (Cucumis sativus L.) seedlings used as the model plant material and on growth of harvested cuttings were investigated to determine optimal LHT conditions. The seedlings received LHT for 12 or 24 h in a lighted or dark growth chamber at air temperatures of 28 to 31 °C and relative humidity of 12% to 25%. Cuttings including a foliage leaf and two cotyledons were harvested by cutting the hypocotyl of the seedlings immediately after the treatment, and then the cuttings were planted in vermiculite medium. Four days after planting, the total fresh weight of the cuttings from seedlings that had received LHT in the lighted chamber was 2.2 times that of cuttings from seedlings that had not received LHT, whereas the total fresh weight of those that had received LHT in the dark increased by 1.3 to 1.8 times. Significant effects of illumination during LHT were also observed in the transpiration rate and growth of the cuttings, harvested following the treatment, after they were planted. By varying LHT duration, it was also found that leaf water potential and leaf conductance of the seedlings decreased as LHT duration increased up to 18 h. Thus, illumination during LHT increased the growth of cuttings taken following the treatment, and optimal treatment duration of around 18 h was estimated from the seedlings' leaf conductance and leaf water potential.
Eric A. Curry and John J. Burke
Development of valid temperature-based models of physiological processes such as seed germination, bud development, vegetative growth, fruit development, or fruit maturation, requires a parameter to link temperature with plant metabolism. The Thermal Kinetic Window (TKW) concept uses the temperature characteristics of an enzyme kinetic parameter, the Michaelis constant (Km) as indicators of metabolic efficiency. Recently, Burke3 has shown that the temperature dependence of the rate and magnitude of the reappearance of photosystem II (PSII) variable fluorescence following illumination corresponded with the optimal temperature described by the TKW for several plant species. The present study investigated the use of the temperature sensitivity of PSII fluorescence in the identification of temperature optima of apple cultivars and rootstocks. 3Burke, J.J. 1990. Plant Physiol. 93:652-656.
Kaori Itagaki, Toshio Shibuya, Motoaki Tojo, Ryosuke Endo, and Yoshiaki Kitaya
× 240 mm width × 50 mm depth) partitioned into 80 square cells and germinated in growth chambers (LPH-220SP; Nippon Medical and Chemical Instruments Co., Ltd., Osaka, Japan) with illumination of R:FR = 1.2, 5.0, or 10 provided by LED lamps (ISL-305X302
C.S. Hew, T.K. Ong, and W.P. Yap
A circadian rhythm in CO2 production was observed in three cultivars of Anthurium andraeanum Andre (`Jaya', `Fla-range', `Leonette') flowers. The rhythmicity was not affected by light, darkness, and detachment. However, the amplitude was dampened in darkness and after detachment. Spadix respiration accounted for 90% of the total flower respiration. Rhythmicity in CO2 production continued after spathe removal. Less pronounced rhythmicity was observed following spadix removal.