scholarly journals Modification of Yield and Chlorophyll Content in Leaf Lettuce by HPS Radiation and Nitrogen Treatments

HortScience ◽  
1991 ◽  
Vol 26 (11) ◽  
pp. 1371-1374 ◽  
Author(s):  
Cary A. Mitchell ◽  
Tina Leakakos ◽  
Tameria L. Ford

This study evaluated the potential of high photosynthetic photon flux (PPF) from high-pressure sodium (HPS) lamps, alone or in combination with metal halide (MH) plus quartz iodide (QI) incandescent lamps, to support lettuce growth, with or without N supplementation. Varying exposures to radiation from combined HPS, MH, and QI lamps influenced dry weight gain and photosynthetic pigment content of hydroponically grown `Black-Seeded Simpson' lettuce (Lactuca sativa L.) seedlings. Cumulative leaf dry weight declined with increasing exposure, up to 20 hours per day, to 660 μmol·m-2·s-1 of photosynthetically active radiation (PAR) from HPS lamps concomitant with constant 20 hours per day of 400 m mol·m-2·s-1 from MH + QI lamps. Leaves progressively yellowed with increasing exposure to radiation from the three-lamp combination, corresponding to lower specific chlorophyll content but not to specific carotenoid content. Lettuce grown under 20-hour photoperiods of 400, 473, or 668 μmolm·m-2·s-1 from HPS radiation alone had the highest leaf dry weight at a PPF of 473 μmol·m-2·s-1. Chlorophyll, but not carotenoid specific content, decreased with each incremental increase in PPF from HPS lamps. Doubling the level of N in nutrient solution and supplying it as a combination of NH4+ and NO3- partially ameliorated adverse effects of high PPF on growth and pigment content relative to treatments using single-strength N as NO3–.

Plants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 93 ◽  
Author(s):  
Most Naznin ◽  
Mark Lefsrud ◽  
Valerie Gravel ◽  
Md Azad

The aim of this study was to investigate the different combinations of red (R) and blue (B) light emitting diode (LEDs’) lighting effects on growth, pigment content, and antioxidant capacity in lettuce, spinach, kale, basil, and pepper in a growth chamber. The growth chamber was equipped with R and B light percentages based on total light intensity: 83% R + 17% B; 91% R + 9% B; 95% R + 5% B; and control was 100% R. The photosynthetic photon flux density (PPFD), photoperiod, temperature, and relative humidity of the growth chamber were maintained at 200 ± 5 μmol m−2 s−1, 16 h, 25/21 ± 2.5 °C, and 65 ± 5%, respectively. It is observed that the plant height of lettuce, kale, and pepper was significantly increased under 100% R light, whereas the plant height of spinach and basil did not show any significant difference. The total leaf number of basil and pepper was significantly increased under the treatment of 95% R + 5% B light, while no significant difference was observed for other plant species in the same treatment. Overall, the fresh and dry mass of the studied plants was increased under 91% R + 9% B and 95% R + 5% B light treatment. The significantly higher flower and fruit numbers of pepper were observed under the 95% R + 5% B treatment. The chlorophyll a, chlorophyll b, and total chlorophyll content of lettuce, spinach, basil, and pepper was significantly increased under the 91% R + 9% B treatment while the chlorophyll content of kale was increased under the 95% R + 5% B light treatment. The total carotenoid content of lettuce and spinach was higher in the 91% R + 9% B treatment whereas the carotenoid content of kale, basil, and pepper was increased under the 83% R + 17% B treatment. The antioxidant capacity of the lettuce, spinach, and kale was increased under the 83% R + 17% B treatment while basil and pepper were increased under the 91% R + 9% B treatment. This result indicates that the addition of B light is essential with R light to enhance growth, pigment content, and antioxidant capacity of the vegetable plant in a controlled environment. Moreover, the percentage of B with R light is plant species dependent.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 585c-585 ◽  
Author(s):  
Chieri Kubota ◽  
Chalermpol Kirdmanee ◽  
Toyoki Kozai

Cymbidium (cv. Lisa rose) PLB (protocorm-like bodies) were cultured in liquid 1/2 MS medium with/without 20 mg g-1 sucrose under continuous lighting conditions. The vessels were shaken at 100 rpm under PPF (photosynthetic photon flux) of 20 and 140 μmol m-2 s-1 and CO2 concentrations outside the vessel (Cout) of 450 and 2000 μmol mol-1 conditions. Photoautotrophic growth was obtained at high PPF and high Cout. The chlorophyll content of the PLB in the medium without sucrose at high PPF and high Cout was almost 3 times that with sucrose at low PPF and low Cout. The number of newly developed PLB with sucrose at low PPF and low Cout was 1.6 times that without sucrose at high PPF and high Cout; the dry weight per unit PLB with sucrose at low PPF and low Cout was almost 3 times that without sucrose at high PPF and high Cout. Photoautotrophic growth of the PLB might be further promoted at higher CO2 concentration (> 1%).


Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 358 ◽  
Author(s):  
Monika Cioć ◽  
Andrzej Kalisz ◽  
Marek Żupnik ◽  
Bożena Pawłowska

A mixture of red and blue light-emitting diodes (LEDs; at a ratio of 7:3, respectively) were used to analyze the effects of different photosynthetic photon flux densities (PPFDs) (40, 80, and 120 µmol m−2 s−1 hereafter known as LED 40, 80, and 120, respectively) on the micropropagation of Gerbera jamesonii Bolus shoots. The experiment also examined the effect of 6-benzyladenine (BA) in 1, 2.5, and 5 µM concentrations in the media. Biometrical observations and analyses of leaf morphometry and photosynthetic pigment content were conducted. Shoot multiplication increased with an increasing BA concentration. A PPFD of 80 µmol m−2 s−1 and 5 µM BA is suggested as efficient for shoot propagation and economically viable. LED 120 increased the leaf blade area and its width, and circularity and elongation ratios. The intensity of light did not affect the fresh weight, which increased at higher BA concentrations (2.5 and 5 μM). The dry weight content decreased with increasing cytokinin concentration; the greatest content was observed on media with 1 µM BA under PPFD 120 µmol m−2 s−1. LED 80 increased the photosynthetic pigments content in the leaves in comparison to the standard intensity of LED 40. Increased BA concentration raises the content of chlorophyll a.


1972 ◽  
Vol 2 (3) ◽  
pp. 377-379 ◽  
Author(s):  
G. E. Mellor ◽  
E. B. Tregunna

Western hemlock, Douglas-fir and lodgepole pine were grown on three different sources of nitrogen. At 18 weeks the relationship between leaf area and leaf dry weight was determined for each species. A linear relationship was found between leaf area and leaf dry weight for all three species. Different nitrogen treatments had no effect on this relationship.


HortScience ◽  
1990 ◽  
Vol 25 (7) ◽  
pp. 751-754 ◽  
Author(s):  
S.M. Southwick ◽  
S.A. Weinbaum ◽  
T.T. Muraoka ◽  
W.R. Krueger ◽  
K.A. Shackel ◽  
...  

Leaf dry weight per leaf area (LDW/LA); weight of leaf N per unit leaf area (LN/LA); leaf dry weight (LDW); and fruit quality, particularly sugar per fruit (SF); fruit fresh weight (FFW); and fruit dry weight (FDW) were measured over a range of daily average incident photosynthetic photon flux values (PPF) (50 to 1000 μmol·s-1·m-2) in 7-year-old prune (Prunus domestics L. syn. `Petite d'Agen') tree canopies. Linear or curvilinear relationships between these leaf attributes and fruit characteristics were significant over the PPF range. Analysis of LDW/LA or LN/LA may be used to indicate tree canopy locations in which fruit size and quality is limited by suboptimal PPF.


HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 436-438 ◽  
Author(s):  
Ruey-Chi Jao ◽  
Chien-Chou Lai ◽  
Wei Fang ◽  
Sen-Fuh Chang

Effects of light generated by red and blue light-emitting diodes on the photomixotrophic growth of Zantedeschia jucunda `Black Magic' plantlets in vitro and tuber formation after transplant under the same PPF and photoperiod were investigated. All five treatments had the same photosynthetic photon flux (PPF, 80 ± 5 μmol·m-2·s-1) and photoperiod (16 hours daytime/8 hours nighttime), leading to the same daily light integral. Results showed that the tubular fluorescent lamp (TFL) treatment had the highest value on chlorophyll content and dry weight accumulation than other treatments using light-emitting diodes (LEDs). In LED treatments, there were no significant differences on dry weight and growth rate but with significant differences on chlorophyll content and plant height when blue light LEDs were added. It revealed that blue light was involved in plant height and chlorophyll development control mechanism. Results also showed that minor difference in 28 days of transplant production (in vitro) among treatments does not extends after 6 months of tuber formation stage grown in greenhouse. At present, blue LEDs cost much more than that of red LEDs, results of this study suggested that using red LEDs alone and powered with AC is feasible for the commercial production of Zantedeschia plantlets in vitro.


2019 ◽  
Vol 136 ◽  
pp. 06003
Author(s):  
Liu Yang ◽  
Qinyuan Li ◽  
Junjiang Shu ◽  
Ling Xiao ◽  
Xinyu Gao ◽  
...  

To study the effects of selenium on physiology, Prunus davidiana seedlings were treated with the irrigation of different selenium concentrations solution. The result showed that the photosynthetic pigment content was relatively higher at selenium concentrations of 0, 0.05 and 0.1 mg/L except for carotenoid content which was the highest at 0.1 mg/L but the lowest in control seedlings. In terms of antioxidant enzyme activity, the activities of peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) in selenium-treated seedlings were all higher than that in control seedlings and especially at the selenium concentration of 1 mg/L. The soluble protein content accumulated most at 0.25 mg/L selenium concentration. The content of malondialdehyde (MDA), as membrane lipid peroxidation index, was the lowest at selenium concentration of 0.5 mg/L. In a word, irrigating lower selenium concentrations could increase the photosynthetic pigment content and higher selenium concentrations enhanced the antioxidant enzyme activity to increase cell protection and kept the P. davidiana seedlings good growth and resistance to adverse environments.


2002 ◽  
Vol 57 (1-2) ◽  
pp. 135-143 ◽  
Author(s):  
Huming Li ◽  
Alfons Radunz ◽  
Ping He ◽  
Georg H. Schmid

Cultivation of the climbing plant Dioscorea zingiberensis at a light intensity of 100 μE · m-2 · sec-1 yields three different phenotypes. Most of the plants grow as green phenotype (DzW). Two further forms differ in their leaf shape and leaf color. Whereas one type exhibits a more pointed leaf shape in the upper part of the plant with leaves appearing yellow-green with white stripes or hatchings (DzY), the other type shows a more round leaf shape with an intensive yellow-green color (DzT). These three plant types differ in their diosgenin content not only in their rhizomes but also in the chloroplasts. In the rhizomes the diosgenin content in the green form is 0.4%, in the DzY-form 0.6% and in the DzT-form even 1.3% of the dry weight. Furthermore, even in chloroplasts of the green DzW-form and of the DzY-form the presence of diosgenin was demonstrated. It occurs there as the epimeric form yamogenin. The DzT-form contains no yamogenin in its chloroplasts. Besides this, these plant forms differ in their chlorophyll and carotenoid content and in their fatty acid composition. Carotenoids increase from 1.3% of total lipids in the green phenotype to 3.3% in the DzYand to 4.2% in the DzT-form. This increase refers to _-carotene as well as to lutein and neoxanthin. The chlorophyll content in the green type is 8.1% and lower in the DzY-form with 7%. The highest chlorophyll content is found in the DzT-form with 12%. Fatty acids in the DzY-form and in the DzT-form have a more unsaturated character than in the green phenotype. The content of the monoenoic acid trans-hexadecenoic acid is considerably lower in both phenotypes when compared to the green phenotype. In both phenotypes the quantity of fatty acids with 16 carbon atoms is reduced, whereas fatty acids with 18 carbon atoms occur in higher concentration. Cultivation of the green phenotype (DzW) at the three light intensities of 10, 100 and 270 μE · m-2 · sec-1 leads to changes of the diosgenin content in rhizomes, to an increase of leaf dry weight, to a reduction of the grana structure in chloroplasts and therewith to a decrease of the chlorophyll content. The total lipid content is highest under the cultivation at 100 μE · m-2 · sec-1 and reduced by 30% at 10 and 270 μE · m-2 · sec-1. Carotenoids, however, are highest in shaded plants (10 μE · m-2 · sec-1) and plants grown under high light conditions of 270 μE · m-2 · sec-1. At 100 μE · m-2 · sec-1 a decrease of saturated fatty acids is observed in comparison to plants grown under shaded conditions.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 537
Author(s):  
Meifang Gao ◽  
Rui He ◽  
Rui Shi ◽  
Yiting Zhang ◽  
Shiwei Song ◽  
...  

To produce high-quality broccoli microgreens, suitable light intensity for growth and phytochemical contents of broccoli microgreens in an artificial light plant factory were studied. Broccoli microgreens were irradiated under different photosynthetic photon flux density (PPFD): 30, 50, 70 and 90 μmol·m−2·s−1 with red: green: blue = 1:1:1 light-emitting diodes (LEDs). The broccoli microgreens grown under 50 μmol·m−2·s−1 had the highest fresh weight, dry weight, and moisture content, while the phytochemical contents were the lowest. With increasing light intensity, the chlorophyll content increased, whereas the carotenoid content decreased. The contents of soluble protein, soluble sugar, free amino acid, flavonoid, vitamin C, and glucosinolates except for progoitrin in broccoli microgreens were higher under 70 μmol·m−2·s−1. Overall, 50 μmol·m−2·s−1 was the optimal light intensity for enhancement of growth of broccoli microgreens, while 70 μmol·m−2·s−1 was more feasible for improving the phytochemicals of broccoli microgreens in an artificial light plant factory.


2020 ◽  
Vol 17 (2) ◽  
pp. 41
Author(s):  
BAHARUDIN BAHARUDIN ◽  
M.R. SUHARTANTO ◽  
S. ILYAS ◽  
A. PURWANTARA

<p>ABSTRAK</p><p>Program pengembangan dan rehabilitasi tanaman kakao membutuh-kan benih bermutu. Mutu benih antara lain ditentukan oleh saat panenyang tepat, terutama berhubungan dengan masak fisiologis. Beberapaindikator penting yang berkaitan dengan masak fisiologis benih adalahkarakteristik biologis dan fisiologis. Penelitian telah dilaksanakan diKebun Induk Benih Pusat Penelitian Kopi dan Kakao (Puslitkoka) Jember,Laboratorium Fisika dan Laboratorium Ilmu dan Teknologi Benih IPB,serta Rumah Kaca Balai Penelitan Bioteknologi Perkebunan Indonesia,Bogor pada bulan Februari-September 2008. Penelitian ini bertujuan untuk(1) mempelajari perubahan biologis dan fisiologis selama perkembanganbenih kakao hibrida, (2) mengetahui hubungan antar berbagai karakterbiologis dan fisiologis benih yang mencerminkan mutu benih, dan (3)menentukan saat panen yang tepat benih kakao hibrida TSH 858 xSca 6 dan ICS 60 x Sca 6. Benih yang digunakan berasal dari hasilpersilangan buatan antara kakao TSH 858 x Sca 6 dan ICS 60 x Sca 6.Umur panen benih yang digunakan dalam penelitian adalah 120, 135, 150,165, dan 180 hari yang dihitung saat setelah antesis, dan setiappengamatan diulang 4 kali. Analisis data disajikan dalam bentuk grafikdengan data primer ditambah standar deviasi dalam program Excel danuntuk mengetahui hubungan dari masing-masing karakter mutu benihdilakukan ”analisis path” menggunakan SAS dari Windows v 9.1. Hasilpenelitian menunjukkan dua fase perkembangan benih. Fase perkem-bangan hingga masak fisiologis (fase 1) dan fase setelah masak fisiologis(fase 2) kakao hibrida TSH 858 x Sca 6 dan ICS 60 x Sca 6. Masakfisiologis benih kakao hibrida TSH 858 x Sca 6 tercapai pada saat 150HSA dan ICS 60 x Sca 6 pada 165 HSA. Daya kecambah, indeks vigor,K CT -R, T 50 , bobot basah dan bobot kering benih, karotenoid dan antosianinbenih dan buah, jumlah daun, dan tinggi bibit dari benih kakao hibridaTSH 858 x Sca 6 dan ICS 60 x Sca 6 mencapai maksimum pada saatmasak fisiologis dan menurun pada fase kedua. Selama periodeperkembangan benih terjadi penurunan total klorofil benih dan buah,sedangkan warna buah kuning mengalami peningkatan. Karakter yangberhubungan langsung dengan mutu benih pada saat masak fisiologisbenih kakao hibrida TSH 858 x Sca 6 dan ICS 60 x Sca 6 adalah warnabuah kuning, indeks vigor, total klorofil benih dan buah, karotenoid danantosianin benih, T 50 , tinggi bibit, K CT -R, dan bobot kering benih.</p><p>Kata kunci: Theobroma cacao, biologi benih, fisiologi benih, karakteristikbenih, mutu benih</p><p>ABSTRACT</p><p>Biological and Physiological Changes as Indicator ofMaturity of Hybrid Cacao Seed</p><p>The development and rehabilitation programs of cacao need highquality seeds. The high quality of cacao seeds is influenced by seedsphysiological maturity and harvesting time. Several important indicatorsrelated to the seed physiological maturity are biological and physiologicalcharacters. The research objectives were: (1) to study biological andphysiological changes during of seed development, (2) to study on thecorrelation of various characteristics related with seeds physiology andquality, (3) to determine the most appropriate harvesting time for hybridcacao seed of TSH 858 x Sca 6 and ICS 60 x Sca 6. The research wasconducted at Coffee and Cacao Research Institute of Indonesia(Puslitkoka) in Jember, IPB Biophysics and Seeds and TechnologyLaboratory and Biotechnology Research Institute for Estate CropsIndonesia glass house in Bogor from February to September 2008. Theseeds were originated from hand pollination of TSH 858 vs Sca 6 and ICS60 vs Sca 6 hybrids from Puslitkoka Jember. The seeds for this researchwere harvested on: 120, 135, 150, 165, and 180 days after anthesis (DAA);with four replications each. Data were analyzed and presented as graphs,standard deviation in excel; while the relationship of each character ofseeds quality was determined using path analysis by SAS for Windows v.9.1. The results showed that the seed physiological changed on two phasesduring its development. The first phase started from seeds development upto physiological maturity for TSH 858 x Sca 6 and as well ICS 60 x Sca 6hybrids, and second phases started after physiological maturity. Thephysiological maturity of each seeds is 150 DAA for TSH 858 x Sca 6 and165 DAA for ICS 60 x Sca 6 hybrids. Seed germination percentage, vigorindex, germination rate (K CT -R and T 50 ), wet and dry weight of seed, seedsand fruits carotenoid content, seed and fruit anthocyanin content, numberof leaves, and height of seedling reached maximum when seed achievedphysiological maturity and decreased afterward. During seed development,there was decreasing of seeds and fruits chlorophyll content and increasedfor the yellow color of fruit. The characters which showed directcorrelation with seeds quality during seed development of TSH 858 x Sca6 and ICS 60 x Sca 6 hybrids are: yellow color of fruit, vigor index,chlorophyll content for seeds and fruit, seed carotenoid and anthocyanincontent, germination rate (T 50, K CT -R), seedling height and seed dry weight.</p><p>Key words: Theobroma cacao, seed biological, seed physiological, seedcharacteristic, seed quality</p>


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