scholarly journals Chlorophyll Fluorescence and Vegetative Propagation of Taxus

HortScience ◽  
2001 ◽  
Vol 36 (5) ◽  
pp. 971-975 ◽  
Author(s):  
Sarah E. Bruce ◽  
D. Bradley Rowe ◽  
James A. Flore
Keyword(s):  
Chlorophyll Fluorescence ◽  
Plant Stress ◽  
Photochemical Efficiency ◽  
Dry Weight ◽  
Visual Assessment ◽  
Taxus Baccata ◽  
Stock Plant ◽  
Plant Selection ◽  
Indirect Measure ◽  
Dark Green

Chlorophyll fluorescence over the course of stem cutting propagation was examined in 10 cultivars of Taxus ×media (Taxus baccata L. × T. cuspidata Sieb. & Zucc.), including `Brownii', `Dark Green Pyramidalis', `Dark Green Spreader', `Densiformis', `Densiformis Gem', `Hicksii', `L.C. Bobbink', `Runyan', `Tauntoni', and `Wardii'. The fluorescence value measured was the ratio of variable over maximum chlorophyll fluorescence (Fv/Fm). This value reflects the maximum dark-adapted photochemical efficiency of photosystem II (PSII) reaction centers involved in photosynthesis and is an indirect measure of plant stress. The objective of this study was to examine Fv/Fm as a method for stock plant selection and for monitoring rooting progress of various cultivars. Fv/Fm varied significantly (P ≤ 0.05) among cultivars, initially and over time. However, there was significant overlap among some cultivars. The Fv/Fm decreased dramatically during cold storage, but usually returned to original levels after several weeks in the propagation beds. This appeared to be a reflection of the reduction of water stress as the cuttings formed roots. Initial stock plant Fv/Fm was not correlated (P ≤ 0.05) with rooting percentage, root number, root dry weight, or root length, indicating that Fv/Fm is not a reliable indicator of stock plant rooting potential. Visual assessment is just as reliable.

scholarly journals 544 Using Chlorophyll Fluorescence in Storage and Vegetative Propagation of Taxus

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 489C-489
Author(s):  
Sarah E. Bruce ◽  
D. Bradley Rowe
Keyword(s):  
Chlorophyll Fluorescence ◽  
Dry Weight ◽  
Practical Method ◽  
Storage Condition ◽  
Storage Conditions ◽  
Taxus Baccata ◽  
Stock Plant ◽  
Storage Duration ◽  
Fluorescence Measurements ◽  
Dark Green

Propagation failures of Taxus are often attributed to cutting collection from stock plants of poor quality. If a quick, reliable method of determining the potential rooting of cuttings based on the condition of a specific stock plant was available for propagators, rooting success could be predicted before investing time, labor, and resources. Our studies examined chlorophyll fluorescence (Fv/Fm) as a potential tool for stock plant selection, assessment of storage conditions, and measurement of stress over the course of propagation. Ten cultivars of Taxus × media (Taxus baccata L. × T. cuspidata Sieb. & Zucc.) were used: Brownii, Dark Green Pyramidalis, Dark Green Spreader, Densiformis, Densiformis Gem, Hicksii, L.C. Bobbink, Runyan, Tauntoni, and Wardii. Storage condition treatments consisted of desiccation (low, medium, and high), duration (34, 70, and 107 days), and temperature (–30, –2.5, 0, 2.5, 5, 10, and 20 °C). Cultivars differed in Fv/Fm initially as well as over time. Correlations were not found between initial stock plant Fv/Fm and rooting percentage, number of roots, root dry weight, or root length, indicating that Fv/Fm is not a reliable indicator of stock plant propagation potential. Short storage duration at –2.5 to 2.5 °C was found to be ideal. Fv/Fm could detect substandard storage conditions only at temperature and desiccation extremes. Although chlorophyll fluorescence measurements do not appear to be a practical method of predicting adventitious rooting, there is a potential for assessing cutting or plant quality before shipping.

scholarly journals Growth, Gas Exchange, and Chlorophyll Fluorescence of Four Ornamental Herbaceous Perennials during Water Deficit Conditions

2006 ◽  
Vol 131 (4) ◽  
pp. 469-475 ◽  
Author(s):  
Terri Starman ◽  
Leonardo Lombardini
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Photochemical Efficiency ◽  
Dry Weight ◽  
Drought Treatment ◽  
Greenhouse Production ◽  
Herbaceous Perennials ◽  
Leaf Level

A study was conducted to characterize the morphological and physiological responses of four herbaceous perennial species subjected to two subsequent drought cycles. Lantana camara L. `New Gold' (lantana), Lobelia cardinalis L. (cardinal flower), Salvia farinacea Benth. `Henry Duelberg' (mealy sage), and Scaevola aemula R. Br. `New Wonder' (fan flower) were subjected to two consecutive 10-day drought cycles. Growth response, leaf gas exchange, and chlorophyll fluorescence were measured during the experiment. The morphology of L. cardinalis and L. camara was not affected by drought, while S. farinacea had reductions in plant height and leaf area and S. aemula had reductions in dry weight. Overall, plant growth and development continued even when substrate water content was reduced to 0.13 mm3·mm-3, which indicated a level of substrate water below container capacity was sufficient for greenhouse production of these species. The drought treatments had little effect on the photochemical efficiency (Fv/Fm) of Photosystem II. An increase in minimal fluorescence (Fo) was observed in S. aemula on the last day of the second cycle. Drought treatment caused increased leaf-level water use efficiency (WUE) at the end of the first cycle in L. cardinalis and S. aemula, but not in L. camara and S. farinacea. Plants of L. camara, S. farinacea, and S. aemula that had received drought during both cycles became more water use efficient by the end of the second cycle, but L. cardinalis did not.

scholarly journals The Role of Leaf Pigment and Antioxidant Levels in UV-B Resistance of Dark- and Light-green Kentucky Bluegrass Cultivars

2005 ◽  
Vol 130 (6) ◽  
pp. 836-841 ◽  
Author(s):  
Xunzhong Zhang ◽  
E.H. Ervin ◽  
R.E. Schmidt
Keyword(s):  
Poa Pratensis ◽  
Plant Stress ◽  
Photochemical Efficiency ◽  
Kentucky Bluegrass ◽  
Ultraviolet B ◽  
Turf Quality ◽  
Dark Green ◽  
Major Factors ◽  
Artificial Uv ◽  
Light Green

Ultraviolet-B [UV-B (280-320 nm)] radiation is one of the major factors causing quality decline of transplanted sod. Pigments and antioxidants are associated with plant stress resistance, but their roles in turfgrass tolerance to UV-B damage are not well understood. The objectives of this study were to determine if kentucky bluegrass (Poa pratensis L.) cultivars with darker green genetic leaf color possessed greater pigment and antioxidant defense capacities and if such characteristics were associated with greater resistance to UV-B. Two cultivars, `Moonlight' (dark green) and `Limerick' (light green), were selected and subjected to continuous, artificial UV-B radiation (70 μmol·m-2·s-1). UV-B irradiation reduced turf quality by 58% (`Moonlight') and 77% (`Limerick') relative to day 1 when measured 10 days after initiation of UV-B exposure. Higher canopy photochemical efficiency (PEc) was found in `Moonlight' relative to `Limerick' under UV-B stress and during recovery. `Moonlight' contained greater levels of chlorophyll (1.5 to1.6-fold), carotenoids (1.3-fold), superoxide dismutase [SOD (1.0-fold)] and catalase [CAT (1.5-fold)] than `Limerick' when measured at 10 days after UV-B initiation. Turfgrass quality and PEc were positively correlated with pigments (chlorophyll and carotenoids) and antioxidant enzymes (SOD and CAT), and negatively correlated with lipid peroxidation. The results suggest that selecting dark-green cultivars with greater pigment content and antioxidant activity may be an effective approach for turfgrass breeders and sod producers to improve tolerance of newly transplanted sod to environments with higher UV-B radiation.

scholarly journals Evaluation of efficacy of carfentrazone + metsulfuron, sulfosulfuron + metsulfuron and halauxifen against Rumex spp. in wheat (Triticum aestivum) in Western Haryana

2021 ◽  
Author(s):  
Sunil Soni ◽  
Samunder Singh ◽  
Rajbir Garg
Keyword(s):  
Electrical Conductivity ◽  
Triticum Aestivum ◽  
Chlorophyll Fluorescence ◽  
Plant Height ◽  
Dry Weight ◽  
Recommended Dose ◽  
Wheat Crop ◽  
Broad Leaf ◽  
Mortality Percentage ◽  
Poor Efficacy

Rumex spp. is most dominating broad-leaf weed of wheat crop. Complaints of poor efficacy of different herbicides against Rumex spp. have reported recently from different locations of Haryana state. Therefore, the present study was carried out under completely randomised design, replicated thrice, using three different herbicides namely carfentrazone + metsulfuron, sulfosulfuron + metsulfuron and halauxifen as treatments applied with three doses against four populations of Rumex spp. Plant height, chlorophyll fluorescence, electrical conductivity, mortality percentage and dry weight were recorded as observations. Results indicated that most of the Rumex biotypes were found resistant against sulfosulfuron + metsulfuron application. Majority of biotypes were moderately controlled by the application of halauxifen. Carfentrazone + metsulfuron effectively controlled the Rumex spp. and provided 70-90 % control to all biotypes at double of the recommended dose. As per results of this study, carfentrazone + metsulfuron can be recommended for control of Rumex spp. in wheat.

scholarly journals Temporal Relationship between Ester Biosynthesis and Ripening Events in Bananas

2002 ◽  
Vol 127 (6) ◽  
pp. 998-1005 ◽  
Author(s):  
Sastry Jayanty ◽  
Jun Song ◽  
Nicole M. Rubinstein ◽  
Andrés Chong ◽  
Randolph M. Beaudry
Keyword(s):  
Chlorophyll Fluorescence ◽  
Ethylene Production ◽  
Temporal Relationship ◽  
Photochemical Efficiency ◽  
Acc Oxidase ◽  
Ethylene Biosynthesis ◽  
Banana Fruit ◽  
Coa Transferase ◽  
Ester Biosynthesis ◽  
Natural Ester

The temporal relationship between changes in ethylene production, respiration, skin color, chlorophyll fluorescence, volatile ester biosynthesis, and expression of ACC oxidase (ACO) and alcohol acyl-CoA transferase (AAT) in ripening banana (Musa L. spp., AAA group, Cavendish subgroup. `Valery') fruit was investigated at 22 °C. Ethylene production rose to a peak a few hours after the onset of its logarithmic phase; the peak in production coincided with maximal ACO expression. The respiratory rise began as ethylene production increased, reaching its maximum ≈30 to 40 hours after ethylene production had peaked. Green skin coloration and photochemical efficiency, as measured by chlorophyll fluorescence, declined simultaneously after the peak in ethylene biosynthesis. Natural ester biosynthesis began 40 to 50 hours after the peak in ethylene biosynthesis, reaching maximal levels 3 to 4 days later. While AAT expression was detected throughout, the maximum level of expression was detected at the onset of natural ester biosynthesis. The synthesis of unsaturated esters began 100 hours after the peak in ethylene and increased with time, suggesting the lipoxygenase pathway be a source of ester substrates late in ripening. Incorporation of exogenously supplied ester precursors (1-butanol, butyric acid, and 3-methyl-1-butanol) in the vapor phase into esters was maturity-dependent. The pattern of induced esters and expression data for AAT suggested that banana fruit have the capacity to synthesize esters over 100 hours before the onset of natural ester biosynthesis. We hypothesize the primary limiting factor in ester biosynthesis before natural production is precursor availability, but, as ester biosynthesis is engaged, the activity of alcohol acyl-CoA transferase the enzyme responsible for ester biosynthesis, exerts a major influence.

scholarly journals MEASUREMENT OF SUN INDUCED CHLOROPHYLL FLUORESCENCE USING HYPERSPECTRAL SATELLITE IMAGERY

2016 ◽  
Vol XLI-B8 ◽  
pp. 911-913
Author(s):  
S. M. Irteza ◽  
J. E. Nichol
Keyword(s):  
Chlorophyll Fluorescence ◽  
Steady State ◽  
Satellite Images ◽  
Plant Stress ◽  
Fluorescence Signal ◽  
Absorption Bands ◽  
Considerable Evidence ◽  
Different Seasons ◽  
Insight Into ◽  
Accurate Indicator

Solar Induced Chlorophyll Fluorescence (SIF), can be used as an indicator of stress in vegetation. Several scientific approaches have been made and there is considerable evidence that steady state Chlorophyll fluorescence is an accurate indicator of plant stress hence a reliable tool to monitor vegetation health status. Retrieval of Chlorophyll fluorescence provides an insight into photochemical and carbon sequestration processes within vegetation. Detection of Chlorophyll fluorescence has been well understood in the laboratory and field measurement. Fluorescence retrieval methods were applied in and around the atmospheric absorption bands 02B (Red wavelength) approximately 690 nm and 02A (Far red wavelengths) 740 nm. Hyperion satellite images were acquired for the years 2012 to 2015 in different seasons. Atmospheric corrections were applied using the 6S Model. The Fraunhofer Line Discrimanator (FLD) method was applied for retrieval of SIF from the Hyperion images by measuring the signal around the absorption bands in both vegetated and non vegetated land cover types. Absorption values were extracted in all the selected bands and the fluorescence signal was detected. The relationships between NDVI and Fluorescence derived from the satellite images are investigated to understand vegetation response within the absorption bands.

scholarly journals THE INFLUENCE OF BIO-ALGEEN S90 ON THE GROWTHOF MULTIFLORA ROSE SEEDLINGS (Rosa multiflora Thunb.)

2019 ◽  
Vol 18 (3) ◽  
pp. 35-43
Author(s):  
Mariusz Szmagara ◽  
Krystyna Pudelska ◽  
Wojciech Durlak ◽  
Barbara Marcinek ◽  
Kamila Rojek
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photochemical Efficiency ◽  
Morphological Characteristics ◽  
Rosa Multiflora ◽  
Plant Growth And Development ◽  
Agent Based ◽  
Photochemical Efficiency Of Psii ◽  
Stimulate Plant Growth ◽  
Maximum Photochemical Efficiency ◽  
Natural Agent

Striving to intensify horticultural production, new and more effective bio-preparations are being sought to stimulate plant growth and development. Bio-algeen S90 is a natural agent based on sea algae, the high bi- ological activity of which results from the high content of natural growth regulators. The aim of the study was to verify the influence of Bio-algeen S90 on the growth, morphological characteristics and chlorophyll fluorescence of Rosa multiflora seedlings. The bio-preparation was applied one, two and three times at con- centrations: 0.1, 0.2, 0.4 and 0.6 mg.dm−3. Following parameters were measured to evaluate the response of plants to the bio-preparation: F0 – initial fluorescence, Fm – maximal fluorescence in the dark-adapted state, Fv/Fm – maximum photochemical efficiency of PSII. All concentrations of the bio-preparation and frequency of its application stimulated the number of shoots in a bush, the length of shoots and the diameter of the root crown of plants intended for budding. The most beneficial was the two-fold bio-preparation application at a concentration of 0.4 mg.dm–3. Bio-algeen also positively influenced the chlorophyll fluorescence parame- ters. The highest mean F0 and Fm values were recorded with the two-fold preparation treatment. There was no significant effect of the bio-preparation on the Fv/Fm index, which was within the range of 0.75–0.66.

Spring Wheat (Triticum aestivum)Cultivar Responses to Trifluralin and Postemergence Herbicides

1995 ◽  
Vol 9 (2) ◽  
pp. 352-355 ◽  
Author(s):  
Sharon A. Clay ◽  
Jim F. Gaffney ◽  
Leon J. Wrage
Keyword(s):  
Spring Wheat ◽  
Plant Stress ◽  
Dry Weight ◽  
Field Studies ◽  
Growth And Yield ◽  
Hard Red Spring Wheat ◽  
Wheat Field ◽  
Shoot Dry Weight ◽  
Cultivar Responses ◽  
Postemergence Herbicides

Trifluralin is used for weed control in wheat but may reduce vegetative growth and yield. Postemergence (POST) herbicides may cause additional plant stress to trifluralin-stressed wheat. Field studies at Groton, SD in 1991 and 1992 and at Highmore, SD in 1992 evaluated the effects of 2,4-D-amine, difenzoquat, metsulfuron, and a combination of fenoxaprop-ethyl + 2,4-D-ester + MCPA-ester on hard red spring wheat cultivars ‘2375,’ ‘Prospect,’ and ‘Butte 86’ seeded in areas treated with preplant incorporated trifluralin either in the spring before seeding (0.56 kg ai/ha) or the previous year (1.12 or 2.24 kg ai/ha). Trifluralin applied alone in the spring, and followed by some POST herbicides, reduced shoot dry weight and grain yield. Trifluralin reduced the yield of Prospect the most and the yield of 2375 the least. Yields of trifluralin-treated wheat were reduced 23% by metsulfuron and 14% by fenoxaprop-ethyl + 2,4-D + MCPA compared to yields of wheat treated with only the respective POST herbicide. Yields were not reduced with any trifluralin-POST herbicide combination when trifluralin was applied a year prior to seeding wheat.

Growth, Fruit Yield, Photosynthetic Characteristics, and Leaf Microelement Concentration of Two Blueberry Cultivars under Different Long-Term Soil pH Treatments

Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 357 ◽  
Author(s):  
Yanqin Jiang ◽  
Qilong Zeng ◽  
Jiguang Wei ◽  
Jiafeng Jiang ◽  
Yajing Li ◽  
...  
Keyword(s):  
Soil Ph ◽  
Photochemical Efficiency ◽  
Dry Weight ◽  
Photosynthetic Characteristics ◽  
Fruit Yield ◽  
Downward Trend ◽  
Branch Number ◽  
Plant Weight ◽  
High Ph ◽  
Flowering Date

Soil pH is a key factor affecting the growth of blueberries. Understanding the response mechanism of blueberries to different pH values and selecting suitable evaluation indexes are the basis of breeding new blueberry cultivars with high pH tolerances. The effects of different soil pH treatments for 17 months on the plant growth, fruit yield, photosynthetic characteristics, and leaf microelement concentration of Vaccinium ashei Reade ‘Climax’ and V. corymbosum hybrid ‘Chaoyue No. 1′ were studied. Plant height, main stem diameter, branch number per plant, leaf dry weight, stem dry weight, root dry weight, and total dry weight decreased with increasing soil pH. With an increase in soil pH, the first flowering date, 50% flowering date, first ripening date, and 50% ripening date of the two cultivars were postponed, and the flower bud numbers per plant, the floret numbers per bud, and yield per plant showed a downward trend. Moreover, the fruit quality decreased, which was reflected in the increase in the titratable acid content (TA) and the decrease in the total soluble solids content (TSS) and the TSS:TA ratio in the high pH treatment. With increasing soil pH, the chlorophyll content index (CCI), maximal photochemical efficiency of the PSII (Fv/Fm), quantum photosynthetic yield of the PSII (Y(II)) and net photosynthetic rate (Pn) of the two cultivars showed a downward trend, and some microelement concentrations in the leaves were imbalanced. Under high pH treatment, ‘Chaoyue No. 1′ had a relatively higher plant biomass and fruit yield, so it had a stronger tolerance to high pH than ‘Climax’ did. More strongly acidified rhizosphere soil capacity, as well as higher CCI, Fv/Fm, Y(II), and Pn values were the main reasons for the high pH tolerance of ‘Chaoyue No. 1′. Compared with destructive biomass indicators such as plant weight, nondestructive indicators such as CCI, Fv/Fm, and Y(II) can be more valuable indicators for fast and accurate evaluation of blueberry tolerance to high pH at early stages of treatment.

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