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1.
Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.  相似文献   

2.
Light-emitting diodes (LEDs) with high-intensity output are being studied as a photosynthetic light source for plants. High-output LEDs have peak emission at approximately 660 nm concentrated in a waveband of +/- 30 nm. Lettuce (Lactuca sativa Grand Rapids') seedlings developed extended hypocotyls and elongated cotyledons when grown under these LEDs as a sole source of irradiance. This extension and elongation was prevented when the red LED radiation was supplemented with more than 15 micromoles m-2 s-1 of 400- to 500-nm photons from blue fluorescent lamps. Blue radiation effects were independent of the photon level of the red radiation.  相似文献   

3.
Light-emitting diodes as a radiation source for plants   总被引：5，自引：0，他引：5  
Development of a more effective radiation source for use in plant-growing facilities would be of significant benefit for both research and commercial crop production applications. An array of light-emitting diodes (LEDs) that produce red radiation, supplemented with a photosynthetic photon flux (PPF) of 30 micromoles s-1 m-2 in the 400- to 500-nm spectral range from blue fluorescent lamps, was used effectively as a radiation source for growing plants. Growth of lettuce (Lactuca sativa L. Grand Rapids') plants maintained under the LED irradiation system at a total PPF of 325 micromoles s-1 m-2 for 21 days was equivalent to that reported in the literature for plants grown for the same time under cool-white fluorescent and incandescent radiation sources. Characteristics of the plants, such as leaf shape, color, and texture, were not different from those found with plants grown under cool-white fluorescent lamps. Estimations of the electrical energy conversion efficiency of a LED system for plant irradiation suggest that it may be as much as twice that published for fluorescent systems.  相似文献   

4.
A wild strawberry strain, Fragaria chiloensis CHI-24-1, produced inflorescences from both parent and asexually propagated daughter plants linked with runners when grown at 23 °C/20 °C (day/night) under a 24 h day-length (DL) of daylight plus nightly lighting by an incandescent lamp, but not under 8 or 16 h DLs. In the present study, the effect of light quality for continuous illuminating at night on floral initiation of CHI-24-1 plants grown under a 24 h DL was examined. The CHI-24-1 plants were grown under a 24 h DL consisting of natural daylight and continuous lighting at night by an incandescent, a blue fluorescent, a red fluorescent or a far-red fluorescent lamp for 40 days in summer and autumn. Also, the CHI-24-1 plants were grown for 40 days in a growth chamber at 25 °C/20 °C (day/night) with natural daylight and continuous lighting at night by red- and four types of far-red light-emitting-diodes (LEDs with peak wavelengths of 660, 700, 735, 780 and 830 nm). In both experiments, floral initiation of the parent and daughter plants was observed under a stereomicroscope. Although more than 50% of the parent and daughter plants initiated flower buds under the incandescent and far-red fluorescent lamps, about 15% and 0% of those initiated flower buds under blue and red fluorescent lamps, respectively. Floral initiation of the parent and daughter plants occurred under the far-red LED light source whose peak wavelength was 735 nm, but not under the red or the other far-red LEDs. From these results, it can be concluded that the effective light wavelength range of nightly continuous illuminating for floral induction in the CHI-24-1 plants is 735 nm in the far-red light region. Hence, the induction of floral initiation by nightly continuous far-red light (735 nm) appeared to be a response mediated by phytochrome.  相似文献   

5.
Perilla plants with red coloured leaves grown in red-enriched light treatments (i.e., red lamps alone (R), a mixture of blue and red lamps (BR), and a mixture of green and red lamps (GR)) had greater dry weight, bigger leaves, and more leaves than those grown in other treatments (i.e., blue lamps alone (B), a mixture of blue and green lamps (BG), and green lamps alone (G)). Although the concentrations of perillaldehyde and limonene in leaf tissues (mg g−1 leaf DW) were 1.6–1.9 and 1.5–1.9 times higher, respectively, in the G treatment than in red-enriched light treatments, the contents of perillaldehyde and limonene per plant (mg/plant) were 1.8 times higher in the BR treatment than those in the G treatment. The content of anthocyanin per plant was also 4.3 times higher in the BR treatment than that in the G treatment. Therefore, within the six different combinations of fluorescent lamps used in the present study, the BR treatment was a suitable light quality for producing plants with high contents of perillaldehyde, limonene, and anthocyanin under controlled environments.  相似文献   

6.
Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the effects of spectral quality on disease development when other wavelengths were included in the light source (MH-, 660/BF-, and 660/735-grown plants) were equivocal. These results demonstrate that spectral quality may be useful as a component of an integrated pest management program for future space-based controlled ecological life support systems.  相似文献   

7.
Summary

Single-node cuttings of sweet potato [(Ipomoea batatas (L.) Lam. ‘Beniazuma’)] were cultured in vitro for 35 d under intermittent blue light (IB), intermittent red light (IR) and intermittent blue-plus-red light (IBR) provided by light-emitting diodes (LEDs) flashing for 10 s three-times min–1. Growth was compared with cuttings cultured under continuous blue (B), red (R) or blue-plus-red (BR) light, or cool-white fluorescent lamps (FL) with a 16 h photoperiod. Dry weights, leaf areas and carbohydrate contents were greater under the IB and IBR treatments than in the FL treatment. Our results show that a novel light source during in vitro culture of sweet potato plantlets may provide an opportunity to improve plant yield in large-scale greenhouses for commercial purposes.  相似文献   

8.
Radiation from high-pressure sodium (HPS) lamps provided more than a 50% increased yield (fresh and dry weight of tops) of loose-leaf lettuce cultivars Grand Rapids Forcing and RubyConn, compared to that obtained by radiation from cool-white fluorescent (CWF) lamps at equal photosynthetic photon flux; yet, input wattage was approximately 36% less. It was postulated that the considerable output of 700 to 850 nm radiation from the HPS lamp was a significant factor of the increased yield. Under HPS lamps, the leaves of both cultivars were slightly less green with very little red pigmentation ('RubyConn') and slightly elongated, compared to CWF, but plant productivity per unit electrical energy input was vastly superior with HPS.  相似文献   

9.
不同光质对韭菜生长及光合特性的影响   总被引：3，自引：0，他引：3  
以791雪韭和紫根红两个韭菜品种为试验材料,设红光、蓝光、红/蓝（3/1）、红/蓝（7/1）4个处理,以白光为对照,研究不同光质对韭菜生长及光合特性的影响。结果表明：红/蓝（7/1）处理下韭菜株高、茎粗、叶宽及干鲜质量比均显著高于其他处理|叶绿素总量、叶绿素a/b值及类胡萝卜素含量均以红光处理最高|光合速率、气孔导度、蒸腾速率以及Fv/Fm、Fv/Fo均以红/蓝（7/1）处理最高,而蓝光处理下有较高的胞间CO2浓度、ФPSⅡ和qP。说明红/蓝（7/1）光质有利于提高韭菜叶片的光合作用,促进植株生长,提高产量。  相似文献   

10.
Obtaining uniform mechano-dwarfing of Arabidopsis thaliana (L.) Heynh. seedlings within dense plantings is problematic. Alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls in both greenhouse and controlled growth environments. Arabidopsis grown under low photosynthetic photon flux (PPF) artificial light grew upright with limited leaf expansion, which enhanced mechano-responsiveness compared to that of rosette-growing plants under filtered sunlight or high PPF artificial light. Hypocotyls of seedlings grown at PPFs > 60 micromoles m-2 s-1 elongated less and had 6% less sensitivity to mechanical stress than seedlings grown at PPFs < 60 micromoles m-2 s-1. Fluorescent lamps alone (F) or fluorescent plus incandescent (F+I) lamps were compared for seedling responses to mechanical stress. Under F lighting, hypocotyl elongation was reduced 25% to 40% by twice-daily brush or plate treatments, and brushed seedlings exhibited more growth reduction than did plate treatments. Seedlings grown under F+I lamps exhibited similar stress-induced growth reduction compared to seedlings grown under F only, but stressed F+I seedlings lodged to a greater extent due to excessive hypocotyl elongation. Temperature-response studies using standardized F-only lighting indicated increased hypocotyl elongation but decreased leaf expansion, and decreased mechano-responsivity to brushing over the temperature range from 20 to 28 degrees C. Daylength studies indicated similar degrees of mechano-inhibition of hypocotyl elongation over the daylength range of 12, 16, 20, and 24 hours, whereas fresh weight of stressed seedling shoots declined compared to controls. A combination of environmental growth parameters that give repeatable, visual mechanical dwarfing of Arabidopsis include low-PPF fluorescent lighting from 55 to 60 micromoles m-2 s-1, ambient temperatures from 22 to 25 degrees C, and twice-daily brush treatments.  相似文献   

11.
The goal of this study was to evaluate the effect of cold cathode fluorescent lamps (CCFLs) on the growth of Gerbera jamesonii var. ‘Rui Kou’ plantlets in vitro in six different light quality ratios: 100% red CCFL (R), 80% R + 20% blue CCFL (B), 70% R + 30% B, 60% R + 40% B, 100% B and white CCFLs (W). Control radiation was provided by conventional heat-generating plant growth fluorescent lamps (PGFLs). Plantlets under CCFLs showed better plantlet height, SPAD value (i.e., leaf chlorophyll content) and root activity (as assessed by root dehydrogenase activity) than those growing under PGFLs while all other growth parameters were comparable with plants under conventional lighting systems.  相似文献   

12.
Summary

Four narcissus cultivars were forced under artificial light using fluorescent lamps which emitted white (307 – 770 nm), blue (393 – 580 nm), red (540 – 760 nm), yellow (450 – 750 nm), or green (387 – 680 nm) light. The photosynthetic photon flux density was 12.5 μmol m–2 s–1, with a 6 h photoperiod. Light colour (wavelength) had no significant effect on flowering date, or on the number of flowers collected (P < 0.05). Narcissus bulbs exposed to blue light (393 – 580 nm) formed shorter, more rigid shoots of lower weight with 13 – 40% shorter leaves.  相似文献   

13.
The effect of a new light source, cold cathode fluorescent lamps (CCFLs), on the growth of peony (Paeonia suffruticosa cv. ‘Wu Long Peng Sheng’) plantlets in vitro was examined in six different light quality ratios: 100% red (R), 80% R + 20% blue (B), 70% R + 30% B, 60% R + 40% B, 100% B and white CCFLs. Control illumination was provided by conventional heat-generating plant growth fluorescent lamps (PGFLs). All plantlet growth parameters were as effective under 70% R + 30% B (the best performing CCFL ratio) as they were under PGFLs. Chlorophyll content (a, b and total) was greater in the range of 60–80% R + 20–40% B, although in general there were no significant differences between the best performing R:B ratio and PGFLs. This study indicates that CCFLs can be used as effectively – if not better – than conventional PGFLs to micropropagate this woody ornamental.  相似文献   

14.
叶用莴苣全株营养累积分配的光谱效应   总被引：1，自引：0，他引：1  
基于高等植物叶绿素吸收光谱的强弱差异性,分别采用波长(442±9)nm蓝光、(457±7)nm蓝光、(521±14)nm绿光、(627±7)nm红光和(655±11)nm红光光谱发光二极管(LED)光源,以300μmol·m~(-2)·s~(-1)光强对叶用莴苣进行12 h·d~(-1)照射处理3周,以温室自然光为对照,研究具有一定能量供应下叶用莴苣生长和营养累积分配的光谱信号调控效应。红光,尤其是红光655处理的叶面积、鲜质量、干质量显著高于对照57.89%~85.04%;尽管蓝光下全株及叶和根的可溶性蛋白质含量均显著高于对照33.26%~181.23%,可是随着光谱波长的减小,可溶性蛋白质在各器官中的分配更加呈现以叶为主的特征。相比之下,随着光谱波长的增加,可溶性糖在各器官中的分配更加呈现以叶为主的特征。此外,蓝光、红光处理全株以及叶和茎器官的可溶性糖含量显著高于对照97.26%~357.54%;红光下叶中的游离氨基酸含量低于对照52.79%~59.01%,且明显抑制了GOT活性,以及游离氨基酸分配以茎为主和根其次的特征,暗示着红光有利于氨基酸向阴生器官或部位转运分配的倾向。  相似文献   

15.
DA—6和BR＋GA3对菠菜生长和光合速率的影响   总被引：27，自引：0，他引：27  
梁广坚  李芸瑛 《园艺学报》1998,25(4):356-360
向菠菜叶面喷两次己酸二乙氨基乙醇酯（ＤＡ６）４０ｍｇ／Ｌ或ＢＲ（０．０３ｍｇ／Ｌ）＋ＧＡ３（２０ｍｇ／Ｌ）水溶液,与对照相比,ＢＲ＋ＧＡ３处理增加了净光合速率、维生素Ｃ含量和地上部重量;显著地增加了株高、叶柄长度和重量以及２月播种菠菜的叶柄重量／地上部重量的比值。ＤＡ６处理不但比对照明显增加地上部重量,而且比ＢＲ＋ＧＡ３处理明显增强了光合速率,增加了１１月播种菠菜叶片长度和重量,降低叶柄占地上部重量的比值,显著增加了叶片可溶性糖和维生素Ｃ的含量。  相似文献   

16.
不同LED光源对青蒜苗生长及叶绿素荧光特性的影响   总被引：8，自引：1，他引：7  
以发光二极管（LED）精量调制光质（红光、蓝光和红蓝混合色光）,以白光（普通日光灯）为对照,研究不同光质对青蒜苗生长及叶绿素荧光特性的影响。结果表明：不同光质对青蒜苗生长及叶绿素荧光特性具有显著或极显著影响,红光处理下株高、假茎粗、假茎长、地上部干质量/鲜质量均最高,极显著高于对照和其他处理,而叶绿素总量及类胡萝卜素含量均以白光处理最高,光合速率、蒸腾速率、气孔导度均以红光处理最大,胞间CO2浓度以白光处理最大;不同光质处理对青蒜苗的叶绿素荧光参数有较大影响,红蓝混合色光处理下Fv/Fm和Fv/Fo均最大,ΦPSⅡ为白光处理最高,但与红光处理差异不显著。红光有利于提高青蒜苗的光合速率,进而促进青蒜苗的生长及干物质积累。  相似文献   

17.
Photosynthetic characteristics, chlorophyll index and leaf area were examined in selected leaves of cucumber (Cucumis sativus L. cv. Euphorbia). In the first experiment, plants of cucumber were grown horizontally at a lighting period of 20 h day−1. Photosynthetic measurements in horizontally growing cucumbers showed that there was no decline in photosynthetic capacity when cucumber leaves are developing under good light conditions. In a second experiment, plants were grown in a traditional high-wire cultivation system under 20 h day−1 lighting period until they reached final height and then exposed to different lighting periods (20 and 24 h day−1) for 3 weeks. In stands of cucumber plants photosynthetic measurements showed that the lower leaves have a significant reduction in photosynthetic capacity due to reduced light conditions. Three weeks exposure to 24 h day−1 lighting period reduced leaf area by 20%. Plant grown under continuous light had also lower chlorophyll index compared to plants grown under 20 h day−1 lighting period.  相似文献   

18.
以早春拱棚栽培‘菊锦’大白菜为试材,无色棚膜为对照,研究有色棚膜对春大白菜光合特性、生长量及产量的影响。结果表明,在相同光量子通量密度(PFD)下,紫膜和红膜处理的气温较高,空气湿度较低;蓝膜和绿膜的气温较低,而空气湿度略高。各处理大白菜叶片光合速率(P_n)日变化呈单峰曲线型,紫膜和红膜的P_n显著大于对照,而蓝膜和绿膜与对照差异不显著;早春棚栽大白菜的光饱和点(LSP)为1133.4~1217.5μmol·m~(-2)·s~(-1),紫膜和红膜的明显高于对照,蓝膜和绿膜与对照无显著差异。各处理大白菜的光补偿点(LCP)、表观量子效率(AQY)、CO_2补偿点和饱和点差异不大,但紫膜的羧化效率(CE)显著高于对照,绿膜的明显低于对照。晴天中午红膜和紫膜的光呼吸速率(P_r)低于对照,光能利用率(LUE)高于对照。核酮糖–1,5–二磷酸羧化酶(RuBPCase)、果糖–1,6–二磷酸酶(FBPase)、景天庚酮糖–1,7–二磷酸酶(SBPase)和转酮醇酶(TK)的活性多以紫膜和红膜较高,绿膜较低。与对照相比,紫膜和红膜的生长量较大,而绿膜的较小,蓝膜与对照差异不显著。紫膜和红膜的经济学产量分别比对照高15.1%和7.8%,而蓝膜和绿膜的比对照低6.4%和15.5%。可见,紫膜和红膜可提高大白菜叶片的光能利用效率,增强光合碳同化能力,从而促进植株生长,产量明显提高;绿膜处理的结果相反。  相似文献   

19.
Plants of two Begonia × hiemalis cultivars (‘Schwabenland’ and ‘Nixe’) were grown in a greenhouse and continuously illuminated (24 h a day) from late October to early March, with light from warm white fluorescent lamps (L“WW”), high pressure mercury lamps (HPI/T) or high pressure sodium lamps (SON/T), each at three irradiance levels (5, 10 or 15 W m?2). The control received light continuously (0.8 W m?2) from incandescent lamps (INC). Every third week, plant material (flower peduncles) was collected for in vitro culture. The adventitious shoot formation was strongly dependent on cultivar, length of mother plant illumination and light source. The use of L“WW”, HPI/T or SON/T improved the regeneration ability of flower peduncle segments compared to control. Prolonged irradiation lowered the regeneration in ‘Schwabenland’, especially when HPI/T lamps were used.  相似文献   

20.
Biomass yield and accumulations of betacyanin, chlorophyll, total polyphenol, and antioxidant activity were evaluated growing red amaranth (Amaranthus tricolor L.) in spring season under five different shades made of white, blue, green, yellow, and black polyethylene, and non-shaded frame. Temperature and light intensity varied significantly (P < 0.05) under the different colored polyethylene shades, and these differences in microclimate are implicated for the variability in growth and accumulations of bioactive compounds. The highest temperature was obtained under the blue polyethylene shade and the plants achieved highest plant height, stem length and leaf number, fresh and dry matter biomass, betacyanins, total polyphenol, and antioxidant activity. The achieved biomass yield and accumulation of bioactive compounds were almost similar to field grown red amaranth in summer season. Blue polyethylene shade has probably ensured the optimum microclimate for growth and development of red amaranth in the studied growing period. Exceptionally the plants grown under green polyethylene shade accumulated highest chlorophyll. Although non-shaded plants received highest sunlight intensity but gave the poor biomass yield as well as accumulated less bioactive compounds than plants grown under blue polyethylene shade due to low air temperature. Thus, the results indicated that blue polyethylene has potentials to increase the yield with health beneficiary bioactive compounds betacyanins, polyphenol and antioxidant activity during the low temperature regime in spring season.  相似文献   

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