scholarly journals Growth and Topological Changes of Citrus limon (L.) Burm. f. `Eureka' in Response to High Temperatures and Elevated Atmospheric Carbon Dioxide

1995 ◽  
Vol 120 (6) ◽  
pp. 1025-1031 ◽  
Author(s):  
Chris A. Martin ◽  
Jean C. Stutz ◽  
Bruce A. Kimball ◽  
Sherwood B. Idso ◽  
David H. Akey
Keyword(s):  
Plant Growth ◽  
Chlorophyll A ◽  
High Temperatures ◽  
Atmospheric Carbon Dioxide ◽  
Citrus Limon ◽  
Branch Points ◽  
Fibrous Root ◽  
Leaf Chlorophyll ◽  
Negative Effect ◽  
Lateral Branches

Growth and topological indices of `Eureka' lemon were measured after 6 months in well-watered and well-fertilized conditions and factorial combinations of moderate (29/21C day/night) or high (42/32C day/night) temperatures and ambient (350 to 380 μmol·mol) or elevated (constant 680 μmol·mol-1) CO2. In high temperatures, plants were smaller and had higher levels of leaf chlorophyll a than in moderate temperatures. Moreover, plants in high temperatures and elevated CO2 had about 15 % higher levels of leaf chlorophyll a than those in high temperatures and ambient CO2. In high temperatures, plant growth in elevated CO2 was about 87% more than in ambient CO2. Thus, high CO2 reduced the negative effect of high temperature on shoot growth. In moderate temperatures, plant growth in elevated CO2 was only about 21% more than in ambient CO2. Irrespective of temperature treatments, shoot branch architecture in elevated CO2 was more hierarchical than those in ambient CO2. Specific shoot extension, a topological measure of branch frequency, was not affected by elevated CO2 in moderate temperatures, but was increased by elevated CO2 enrichment in high temperatures-an indication of decreased branch frequency and increased apical dominance. In moderate temperatures, plants in elevated CO2 had fibrous root branch patterns that were less hierarchical than at ambient CO2. The lengths of exterior and interior fibrous roots between branch points and the length of second-degree adventitious lateral branches were increased >50% by high temperatures compared with moderate temperatures. Root length between branch points was not affected by CO2 levels.

scholarly journals Interactive effect of potassium and cadmium on growth, root morphology and chlorophyll a fluorescence in tomato plant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rachida Naciri ◽  
Meryeme Lahrir ◽  
Chahinez Benadis ◽  
Mohamed Chtouki ◽  
Abdallah Oukarroum
Keyword(s):  
Plant Growth ◽  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Root Morphology ◽  
Chlorophyll A Fluorescence ◽  
Tomato Plant ◽  
Cd Stress ◽  
Negative Effect ◽  
Cd Translocation ◽  
The Impact

AbstractA hydroponic experiment was conducted to evaluate the role of potassium (K) in tomato plant growth exposed to cadmium (Cd) stress. In this work, the effects of three potassium nutrition regimes (155, 232 and 310 ppm of K) combined with Cd at different levels (0, 12 and 25 µM of CdCl2) on chlorophyll content index, root and shoot dry weights, root morphology, chlorophyll a fluorescence and translocation factor were analyzed. The results showed a negative effect of cadmium, at different concentrations, on all these parameters. However, optimization of K nutrition has shown promising results by limiting the negative effect of Cd. A positive effect of the high concentration of K (310 ppm) was observed on leaf chlorophyll content and chlorophyll a fluorescence compared to 232 and 155 ppm under Cd stress. K supply improved the electron transport at PSI side indicated by the increase in the amplitude of the I–P phase of OJIP transient. Also, K at a concentration of 310 ppm significantly reduced Cd translocation from root to shoot and improved root and shoot growth parameters in the presence of Cd. K supplementation can reduce the negative effect of Cd by improving photosynthesis and promoting chlorophyll synthesis. The optimization of nutrients composition and concentration might be a good strategy to reduce the impact of Cd on plant growth and physiology.

Low Concentration of Cobalt Increases Growth, Biochemical Constituents, Mineral Status and Yield in Zea Mays

2008 ◽  
Vol 1 (1) ◽  
pp. 128-137 ◽  
Author(s):  
Cheruth Abdul Jaleel ◽  
Zhao Changxing ◽  
K Jayakumar ◽  
M Iqbal
Keyword(s):  
Zea Mays ◽  
Chlorophyll A ◽  
Growth Parameters ◽  
Growth And Yield ◽  
Content Increase ◽  
Seedling Vigour ◽  
Total Sugars ◽  
Chlorophyll Contents ◽  
Negative Effect ◽  
Maize Plants

A pot culture experiment has been carried out to find the extent of changes occurring in the biochemicals and nutrients of maize plants (Zea mays L.) grown under different concentrations of cobalt (50, 100, 150, 200, 250 mg kg-1 soil). The growth and yield parameters such as seedling vigour, number of cobs, number of seeds per plant; photosynthetic pigments viz., chlorophyll ‘a’, chlorophyll ‘b’, and total chlorophyll contents; biochemicals like total sugars (reducing and non reducing), starch, amino acids and protein content and various macro- and micronutrients are determined 90 days after sowing (DAS). All the growth parameters, pigment content, biochemicals and mineral content increase at 50 mg Co kg-1 soil when compared with the control. Further increase in the Co levels (100-200 mg kg-1 soil) has a negative effect on all the above parameters.   Keywords: Cobalt; Growth; Zea mays; Biochemicals; Nutrients. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  DOI: 10.3329/jsr.v1i1.1226 

scholarly journals Zooplankton body-size structure and biomass in tropical floodplain lakes: relationship with planktivorous fishes

2012 ◽  
Vol 23 (3) ◽  
pp. 217-228 ◽  
Author(s):  
Claudia Costa Bonecker ◽  
Fábio de Azevedo ◽  
Nadson Ressyé Simões
Keyword(s):  
Chlorophyll A ◽  
Size Structure ◽  
Zooplankton Community ◽  
Dry Season ◽  
Size Class ◽  
Fish Density ◽  
Upper Paraná River Floodplain ◽  
Negative Effect ◽  
Density And Biomass ◽  
Number Of Individuals

AIM: This study evaluated whether the size structure of the zooplankton community, as analyzed from density and biomass, would be influenced by bottom-up and/or top-down mechanisms in isolated lakes from the Upper Paraná River floodplain during dry and rainy periods. METHODS: zooplankton individuals were classified as: smaller-sized (<300 µm), intermediate-sized (301 to 600 µm) and larger-sized (greater than 601 µm). Fish abundance was indexed by the capture per unit effort (CPUE; number of individuals.100 m-2). Productivity was measured as chlorophyll-a. RESULTS: The size structure of the community did not show significant relationship with chlorophyll-a concentration (p > 0.05), but it was associated to the increase in fish density during the dry season. The percentage of individuals with intermediate sizes (301 to 600 µm), in both biomass and density, was positively related to the fish density (R2 = 0.78 for biomass, p < 0.001; R2 = 0.58 for density, p = 0.02), indicating an increase numerical and mass of this size class with fish density. The percentage of larger-sized individuals (>600 µm), in both biomass (R2 = 0.86, p < 0.001) and density (R2 = 0.69, p = 0.02) was negatively associated to the fish density, reflecting a decrease of this size class with the increase of fish in the environment. CONCLUSIONS: This can implicate a direct and negative effect of the predation on larger-sized individuals, as well as indirect and positive effect on the intermediate-sized individuals, but it occurred only on dry season. Thus, different mechanisms act on the size structure of the zooplankton community between dry and rainy season.

Effect of sulphur dioxide and ozone singly or in combination on leaf chlorophyll, RNA, and protein in white bean

1979 ◽  
Vol 57 (18) ◽  
pp. 1940-1945 ◽  
Author(s):  
D. W. Beckerson ◽  
G. Hofstra
Keyword(s):  
Chlorophyll A ◽  
Sulphur Dioxide ◽  
Control Group ◽  
Normal Leaf ◽  
Protein Levels ◽  
Leaf Chlorophyll ◽  
Leaf Drop ◽  
White Bean ◽  
Chlorophyll A And B ◽  
Rna Levels

The effect of 0.15 ppm ozone and (or) 0.15 ppm sulphurdioxide on leaf chlorophyll, RNA, and protein levels was investigated. Ozone-treated leaves exhibited reddish-brown colored lesions and an immediate and continuous decrease in chlorophyll a and b levels over a 5-day period, whereas protein levels increased and there was no effect on RNA levels compared to the control group of plants. Sulphur dioxide-treated leaves exhibited an immediate increase in chlorophyll a and b, but protein and RNA levels were not affected. The sulphur dioxide – ozone mixture caused an interveinal chlorisis by about day 3 and produced a decrease in chlorophyll a and b which was delayed by 2 days compared with leaves exposed to ozone alone. By the end of the 5-day period, chlorophyll a and b levels were less than in leaves treated with ozone alone, but the interveinal chlorosis that occurred was not due to phaeophytinization of the chlorophyll molecules. Protein and RNA levels were not affected. Although both ozone and the pollutant mixture caused chlorophyll destruction and premature leaf drop, the changes that occurred in the leaf were not typical of normal leaf senescence.

CHANGES IN LEAF PIGMENTS DURING SENESCENCE AND CURING OF FLUE-CURED TOBACCO

1984 ◽  
Vol 64 (1) ◽  
pp. 229-232 ◽  
Author(s):  
WILLIAM A. COURT ◽  
JOHN G. HENDEL
Keyword(s):  
Nicotiana Tabacum ◽  
Plant Growth ◽  
Chlorophyll A ◽  
Chlorophyll B ◽  
Nicotiana Tabacum L ◽  
Pigment Concentrations ◽  
Oxygen Substitution ◽  
Β Carotene ◽  
Carotenoid Degradation

Neoxanthin, violaxanthin, lutein, β-carotene, chlorophyll a and chlorophyll b in the leaves of flue-cured tobacco (Nicotiana tabacum L.) were determined in samples collected at intervals from the middle of July through harvest. Harvested leaves were also sampled at intervals during flue curing for pigment determinations. Except where interrupted by rainfall or irrigation, pigment concentrations progressively declined during plant growth; this degradation was accelerated during flue curing. Carotenoid degradation during flue curing was proportional to the degree of oxygen substitution of the carotenoid. Chlorophyll a and chlorophyll b in cured tissue were typically less than 1% of the amounts present at harvest.Key words: Carotenoids, chlorophyll, tobacco (flue-cured), flue curing, senescence

Leaf optical properties in Liriodendrontulipifera and Pinusstrobus as influenced by increased atmospheric ozone and carbon dioxide

1995 ◽  
Vol 25 (3) ◽  
pp. 407-412 ◽  
Author(s):  
Gregory A. Carter ◽  
Joanne Rebbeck ◽  
Kevin E. Percy
Keyword(s):  
Carbon Dioxide ◽  
Optical Properties ◽  
Chlorophyll A ◽  
Atmospheric Ozone ◽  
Open Top Chambers ◽  
Chlorophyll Contents ◽  
Optical Responses ◽  
Leaf Chlorophyll ◽  
Leaf Optical Properties ◽  
Nm Range

Seedlings of Liriodendrontulipifera L. and PinusstrobusL. were grown in open-top chambers in the field to determine leaf optical responses to increased ozone (O3) or O3 and carbon dioxide (CO2). In both species, seedlings were exposed to charcoal-filtered air, air with 1.3 times ambient O3 concentrations (1.3×), or air with 1.3 times ambient O3 and 700 μL•L−1 CO2 (1.3× + CO2). Exposure to 1.3× increased reflectance in the 633–697 nm range in L. tulipifera. Also, 1.3× decreased transmittance within the 400–420 nm range, increased transmittance at 686–691 nm, and decreased absorptance at 655–695 nm. With 700 μL•L−1 CO2, O3 did not affect reflectance in L. tulipifera, but decreased transmittance and increased absorptance within the 400–421 nm range and increased transmittance and decreased absorptance in the 694–697 nm range. Under 1.3×, reflectance in P. strobus was not affected. However, 1.3× + CO2 increased pine reflectance in the 538–647, 650, and 691–716 nm ranges. Transmittances and absorptances were not determined for P. strobus. Reflectance in both species, and transmittance and absorptance in L. tulipifera, were most sensitive to O3 near 695 nm. Reflectance at 695 nm, but particularly the ratio of reflectance at 695 nm to reflectance at 760 nm, was related closely to ozone-induced decreases in leaf chlorophyll contents, particularly chlorophyll a (r = 0.82).

scholarly journals Kadar pati akar dan sitokinin endogen pada tanaman teh menghasilkan sebagai dasar penentuan pemangkasan dan aplikasi zat pengatur tumbuh

Kultivasi ◽  
2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Intan Ratna Dewi Anjarsari ◽  
Jajang Sauman Hamdani ◽  
Cucu Suherman Victor Zar ◽  
Tati Nurmala ◽  
Heri Sahrian ◽  
...  
Keyword(s):  
Plant Growth ◽  
Starch Content ◽  
Nutrient Status ◽  
Tea Plant ◽  
Endogenous Cytokinin ◽  
Sources And Sinks ◽  
Qualitative Test ◽  
Root Starch ◽  
Tea Plants ◽  
Lateral Branches

ABSTRAK Pemangkasan pada tanaman teh dilakukan salah satunya untuk menginisiasi tumbuhnya banyak tunas sebagai bakal pembentukan pucuk peko. Pemangkasan mengubah luas daun, kapasitas fotosintesis perdu, mempengaruhi keseimbangan metabolisme antara organ di atas dan di bawah tanah dengan  mengurangi  jumlah tumbuh tunas yang berfungsi sebagai sumber dan pengguna untuk nutrisi dan hormon. Sampai saat ini pertumbuhan tunas sebagai bakal daun setelah pemangkasan terjadi secara alami tanpa penambahan zat pengatur tumbuh (ZPT). Pada dasarnya rekayasa fisiologis dengan menggunakan ZPT sitokinin dapat menjadi pilihan untuk lebih memacu pertumbuhan cabang lateral dan tunas serta memecahkan dormansi pucuk. Tujuan penelitian pendahuluan ini  adalah untuk mengetahui   kadar pati akar, kadar sitokinin endogen, serta status hara tanah  guna menentukan waktu pemangkasan yang tepat dan dasar untuk dilakukan aplikasi zat pengatur tumbuh setelah dipangkas. Penelitian selanjutnya adalah penggunaan sitokinin BAP pada berbgai dosis pada tanaman teh yang sudah dipangkas.  Penelitian pendahuluan dilakukan pada bulan Agustus  hingga Oktober 2017 di kebun percobaan Pusat Penelitian Teh dan Kina (PPTK) Gambung  pada ketinggian 1250 m di atas permukaan laut (dpl). Metode pengambilan sampel daun, akar, dan tanah di lapangan dilakukan secara komposit untuk setiap ulangan selanjutnya dilakukan analisis pati akar, sitokinin endogen serta hara tanah. Hasil uji kualitatif pati akar menggunakan iodium mengindikasikan bahwa tanaman teh siap untuk dipangkas terlihat dari sampel akar yang ditetesi iodium menunjukkan warna hitam. Hasil analisis laboratorium menunjukkan bahwa kadar pai akar berada pada kisaran 6.99 % hingga 9,16% dan sitokinin endogen ada pad akisaran 0,0016% hingga0,0019%.  Penentuan kadar pati akar, kondisi lingkungan serta status hara sebelum pemangkas diperlukan agar meminimalisasi tingkat kematian perdu teh serta analisis sitokinin endogen diperlukan untuk lebih  mengoptimalkan dosis sitokinin yang akan diberikanKata Kunci : pemangkasan, sitokinin endogen, kadar pati akar. ABSTRACT  Pruning on tea plants is  perfomed initiating growth of shoots to be pecco stadia. Pruning changes the leaf area, the capacity of photosynthetic tea bush, affecting the metabolic balance between upper and underground organs by reducing the growing number of buds that function as sources and sinks for nutrients and hormones. Until now the growth of shoots as leaf will after pruning occurs naturally without the addition of plant growth regulating substances (PGR). Essentially physiological engineering using  cytokinins can be an option to increase the growth of lateral branches and buds as well as break the shoot dormancy. The preliminary study was conducted from August to October 2017 at experimental field of Gambung Tea and Quinine Research Center (PPTK) at an altitude of 1250 m above sea level (asl). Preliminary method used in the form of analysis of root starch, endogenous cytokinin and soil nutrients to  determined the proper pruning time and the basis for the application of  plant growth regulator substances after pruning. The results of a qualitative test of root content using iodine indicated that the tea plant was ready to be pruned visible from the root samples that iodized spots showed black. The result of  laboratory test  showed that root starch content was in the range of 6.99 to 9.16. and cytokinin endogen  preliminary analysis showed that the levels are in the range of 0.0016 up to 0.0019. Determination of root starch, environmental conditions and nutrient status before pruning is necessary in order to minimize mortality rate of tea bush as well as analysis of endogenous cytokinin is needed to further optimize the dose of cytokinin to be given. Keywords : cytokinins, pruning,  root starch content

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