Survival of rice during complete submergence: effect of potassium bicarbonate application

1999 ◽  
Vol 26 (8) ◽  
pp. 793 ◽  
Author(s):  
P. Krishnan ◽  
G. Ramakrishnayya

The effect of potassium bicarbonate application to floodwater on the survival and growth of submergence-tolerant (FR13A) and -intolerant (IR42) rice cultivars during complete submergence was investigated. Potassium bicarbonate, applied at different rates to enhance floodwater carbon dioxide concentrations, increased the floodwater oxygen concentration. The treatment that had CuSO4, added alone to reduce algal growth showed the lowest O2 concentration at the time of submergence and after 10 d of submergence. Potassium bicarbonate at higher rates tended to maintain the floodwater pH near neutrality while copper sulfate affected pH increase during a 10-day period of complete submergence. Potassium bicarbonate addition led to 100% survival of tolerant FR13A. Potassium bicarbonate, even at 0.01 mol m–3 enhanced the survival of intolerant IR42 to 69% and at 0.1, 0.5 and 1.0 mol m–3, the survival was above 85%. Dry weights of submerged plants showed increases in both rice cultivars in floodwater treated with potassium bicarbonate. The dry weight and leaf chlorophyll concentration of both cultivars increased with increasing rates of potassium bicarbonate. Algal chlorophyll concentration of floodwater treated with potassium bicarbonate was comparable to that of the control without copper sulfate. The findings suggest a possibility of environmental manipulation of floodwater by potassium bicarbonate application to enhance the survival and growth of rice cultivars during complete submergence.

1999 ◽  
Vol 26 (6) ◽  
pp. 613 ◽  
Author(s):  
María Luisa Izaguirre-Mayoral ◽  
Margarita Sicardi de Mallorca

Present investigation was undertaken to analyse the effect of root volume restriction on the physiological performance of Rhizobium-inoculated (R+ ) and nitrogen-supplied (N+) cowpea (Vigna unguiculata (L.) Walp. var. Tuy.) and bean (Phaseolus vulgaris L. var. Montalbán.) plants. Restriction of root volume (RRV) was imposed via an 8-fold reduction in the rooting space. Plants were grown under controlled conditions and an unlimited availability of water and nutrients. For both plant species, RRV reduced the dry weight of roots, shoots and nodules, retarded the rate of leaf initiation and development, and increased the leaf chlorophyll concentration, regardless of the source of nitrogen. In contrast, RRV did not alter the shoot/root, leaf/root and nodule/root ratios, the concentration of total reducing sugars in shoots, roots and nodules, the leaf relative water content or the concentration of Rubisco in mature leaves of R+ and N+ bean and cowpea plants. Concentration of ureide and α-amino-N in shoots and nodules of R+ plants as well as of α-amino-N in shoots of N+ plants were also not affected by RRV, and abscission of trifoliolated leaves was not recorded in any of the treatment combinations. We conclude that dwarfism of RRV plants was not due to water stress, decreased rates of assimilation, increased abscisic acid, sink/source alterations, or to a reduction on the effectiveness of the symbiotic process or of nitrogen uptake in R+ and N+ plants, respectively.


HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 497e-497
Author(s):  
Jodie Benson ◽  
John Kelly

Tomato and pepper transplants were grown in an environment with a high red to far-red light ratio, to determine if this was an effective method for controlling plant height. This light environment was provided by placing plants under copper sulfate filters, which absorb most of the light in the far-red region of the spectrum. Copper sulfate solutions were 4%, 8%, and 16% w/v. Tomato transplants grown under the filters were approximately 40% shorter than control plants, had less dry weight and leaf area, and increased leaf chlorophyll. Leaf number data was less clearly affected. Differences were not observed among the three different CuSO4 concentrations. Similar results were observed for peppers. Field trials on tomatoes indicated that total yield, earliness of fruiting, and fruit quality were not affected by growing transplants under the CUSO4 filters.


1996 ◽  
Vol 33 (6) ◽  
pp. 129-138 ◽  
Author(s):  
Mohammad I. Abdel-Hamid

A simple microplate technique was adopted for toxicity assessment of a number of pesticides including six herbicides (Atrazine, Dichloroprop, Glyphosphate, Chlorsulfuron, MCPA, and Simazine), an insecticide (Dimethoate) and a fungicide (Propiconazol). Growth response of free and immobilized cultures of the green chlorococcal algae Selenastrum capricornumtum to different treatments of these pesticides was tested and compared. The biotests were carried out under conditions optimal for the growth of the test alga. Algal growth was exposed in terms of dry weight, and was employed as the toxicity-response parameter. Dose-response curves were used to calculate the toxicity of the tested compounds in terms of EC50. Based on EC50 values, the responses of both immobilized and free cultures were quite similar for almost all the treatments. The technique facilitated the visual detection of the lowest toxic concentration giving no detectable algal growth (EC100). The technique is quite simple, rapid, practical, accurate, and space saving. It suggested that batteries of immobilized algae could replace free cultures in studies of toxicity testing.


2013 ◽  
Vol 31 (2) ◽  
pp. 291-302 ◽  
Author(s):  
F.B. Cerqueira ◽  
E.A.L. Erasmo ◽  
J.I.C. Silva ◽  
T.V. Nunes ◽  
G.P. Carvalho ◽  
...  

The objective of this study was to evaluate the competitiveness of two cultivars of upland rice drought-tolerant, cultured in coexistence with weed S. verticillata, under conditions of absence and presence of water stress. The experiment was conducted in a greenhouse at the Experimental Station of the Universidade Federal de Tocantins, Gurupi-TO Campus. The experimental design was completely randomized in a factorial 2 x 2 x 4 with four replications. The treatments consisted of two rice cultivars under two water conditions and four densities. At 57 days after emergence, were evaluated in rice cultivars and weed S. verticillata leaf area, dry weight of roots and shoots and total concentration and depth of roots. Was also evaluated in rice cultivars, plant height and number of tillers. Water stress caused a reduction in leaf area, the concentration of roots and vegetative components of dry matter (APDM, and MSR MST) of rice cultivars and Jatoba Catetão and weed S. verticillata. The competition established by the presence of the weed provided reduction of all vegetative components (MSPA, and MSR MST) of cultivars and Jatoba Catetão. It also decreased the number of tillers, the concentration of roots and leaf area. At the highest level of weed competition with rice cultivars, a greater decrease in vegetative components and leaf area of culture, regardless of water conditions.


2016 ◽  
Vol 3 (1) ◽  
pp. 26-29
Author(s):  
Prabhakaran J ◽  
Kavitha D

A laboratory study was conducted to assess the herbicidal potential of root exudates of three rice cultivars (ADT-36, BPT and IR-20) against germination and growth of common crop field weed, barnyard grass (Echinochloa crus-galli L.). Various concentrations (5, 10, 15 and 20%) of root exudates were prepared from the underground part of rice cultivars from the postharvest rice fields. The studies revealed that all the three rice cultivars were exhibited significant inhibition on growth and development of weed species. Among the rice cultivars, ADT-36 exhibited the greatest inhibition on the seed germination (86%), seedling growth(83%), dry weight (81%) of barnyard cross than BPT and ADT-36. The percentage of inhibition on concentration depends. The order of inhibition of the rice cultivars was ADT-36 > BPT > IR-20 on barnyard grass.


2021 ◽  
Vol 8 ◽  
Author(s):  
Rosemary Kate Steinberg ◽  
Emma L. Johnston ◽  
Teresa Bednarek ◽  
Katherine A. Dafforn ◽  
Tracy D. Ainsworth

Ocean warming driven bleaching is one of the greatest threats to zooxanthellate cnidarians in the Anthropocene. Bleaching is the loss of Symbiodiniaceae, chlorophyll, or both from zooxanthellate animals. To quantify bleaching and recovery, standardised methods for quantification of Symbiodiniaceae and chlorophyll concentrations have been developed for reef-building scleractinian corals, but no such standard method has been developed for octocorals. For stony corals, quantification of Symbiodiniaceae and chlorophyll concentrations often relies on normalisation to skeletal surface area or unit of biomass [i.e., protein, ash-free dry weight (AFDW)]. Stiff octocorals do not change their volume, as such studies have used volume and surface area to standardise densities, but soft-bodied octocorals can alter their size using water movement within the animal; therefore, Symbiodiniaceae and chlorophyll cannot accurately be measured per unit of surface area and are instead measured in units of Symbiodiniaceae and chlorophyll per μg of host protein or AFDW. Though AFDW is more representative of the full biomass composition than host protein, AFDW is more time and resource intensive. Here, we provide a streamlined methodology to quantify Symbiodiniaceae density, chlorophyll concentration, and protein content in soft-bodied octocorals. This technique uses minimal equipment, does not require freeze-drying or burning samples to obtain ash weight, and is effective for down to 0.2 g wet tissue. Bulk samples can be centrifuged, the Symbiodiniaceae pellet washed, and the supernatant saved for protein analysis. This efficient technique allows for clean, easy to count samples of Symbiodiniaceae with minimal animal protein contamination. Chlorophyll a and c2 extractions occurs at different rates, with chlorophyll a taking 24 h to extract completely at 4°C and chlorophyll c2 taking 48 h. Finally, we found that where necessary, wet weight may be used as a proxy for protein content, but the correlation of protein and wet weight varies by species and protein should be used when possible. Overall, we have created a rapid and accurate method for quantification of bleaching markers in octocorals.


1995 ◽  
Vol 120 (2) ◽  
pp. 283-285 ◽  
Author(s):  
Yan Shi ◽  
D. H. Byrne

A standardized screening procedure for tolerance to bicarbonate-induced Fe chlorosis using a commercial fertilizer mix (Plantex) as the nutrient source, high solution pH (8.5) and 1.5 m m bicarbonate to simulate a calcareous soil situation was used with a 1 vermiculite:1 perlite (v/v) support media, small pots and topping (pinching back the tops of shoots). The tolerance level of peach [Prunus persica (L.) Batsch] rootstock could be assessed by leaf visual-chlorosis ratings and Spad-502 chlorophyll readings instead of extractable leaf-chlorophyll concentration or plant Fe concentration. Although most of the tolerant genotypes had almond [P. amygdalus (Mill.) D.A. Webb] in their parentage, a few peaches (`Swat', NJ672281007) showed high to moderate levels of tolerance.


2021 ◽  
Vol 33 (5) ◽  
pp. 2863-2873
Author(s):  
Anna-Lena Höger ◽  
Carola Griehl ◽  
Matthias Noll

AbstractIn recent years microalgae products have developed increasing market demand, but sustainable industrial production is still challenged by biological stability of large-scale production plants. Yet the relationships between algal hosts, associated microbiomes, and contaminants in photobioreactors remains widely understudied. The aim of this study was to investigate the temporal development of microbiomes of four freshwater microalgae species Scenedesmus vacuolatus, Desmodesmus quadricauda, Chlorella sorokiniana, and Botryococcus braunii, in presence and absence of the zoosporic parasite Amoeboaphelidium protococcarum. To compare the effects of sterile and nonsterile culture conditions, infection experiments were performed in sterile laboratory (sterile) and simulated industrial conditions (open). Algal growth (dry weight, optical density, and nutrient consumption) was observed for 21 days, and samples of the associated microbiome were collected for bacterial 16S rRNA gene Illumina MiSeq sequencing. Infection patterns of A. protococcarum were algae species-specific, irrespectively of culture conditions. Bacterial community analysis demonstrated distinct and stable bacterial communities for each algae species, which were mostly dominated by α- and γ-Proteobacteria. Upon aphelid parasitosis, bacterial diversity increased, and community compositions diverged algae-specific over time. Moreover, bacterial functional traits shifted to detoxification, degradation, and cellulolysis once algae were infected. This study provides a first insight into the close connection between algae, associated bacterial microbiomes and appearing contaminants in photobioreactor systems.


2014 ◽  
Vol 42 (2) ◽  
pp. 386-391 ◽  
Author(s):  
Meral INCESU ◽  
Berken CIMEN ◽  
Turgut YESILOGLU ◽  
Bilge YILMAZ

Salinity continues to be a major factor in reduced crop productivity and profit in many arid and semiarid regions. Seedlings of Diospyros kaki Thunb. and D. virginiana L. are commonly used as rootstock in persimmon cultivation. In this study we have evaluated the effects of different salinity levels on photosynthetic capacity and plant development of D. kaki and D. virginiana. Salinity was provided by adding 50 mM, 75 mM and 100 mM NaCl to nutrient solution. In order to determine the effects of different salinity levels on plant growth, leaf number, plant height, shoot and root dry mass were recorded. Besides leaf Na, Cl, K and Ca concentrations were determined. Also leaf chlorophyll concentration, chlorophyll fluorescence (Fv’/Fm’) and leaf gas exchange parameters including leaf net photosynthetic rate (PN), stomatal conductance (gS), leaf transpiration rate (E), and CO2 substomatal concentration (Ci) were investigated. Significant decrease of leaf number, shoot length and plant dry mass by increasing salinity levels was observed in both rootstocks. D. virginiana was less affected in terms of plant growth under salinity stress. Leaf chlorophyll concentration reduction was higher in the leaves of D. kaki in comparison to D. virginiana in 100 mM NaCl treatment. By increasing salinity levels PN, gS and E markedly decreased in both rootstocks and D. kaki was more affected from salinity in terms of leaf gas exchange parameters. In addition there was no significant difference but slight decreases were recorded in leaf chlorophyll fluorescences of both rootstocks.


Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 263-269
Author(s):  
Lars W.J. Anderson ◽  
Nathan Dechoretz ◽  
David Bayer ◽  
Gary L. Darmstadt

Copper content and growth of excised hydrilla [DioeciousHydrilla verticillata(L.f.) Royle # HYLLI] apical shoot segments were determined following exposure to copper sulfate (CuSO4), copper-triethanolamine (Cu-TEA), and copper-ethylenediamine (Cu-EDA). For all copper formulations, inhibition of growth was related to the amount of copper associated with the excised shoots. At equal copper exposure, the Cu-EDA formulation produced the greatest inhibition of growth and generally the highest copper levels in the plants. The Cu-EDA formulation inhibited dry weight gain by more than 80% 3 weeks after a 2-h exposure to 2.0 or 4.0 ppmw copper. Under similar conditions, CuSO4or Cu-TEA produced 60% inhibition. The presence or absence of light during a 2-h exposure had no effect on the efficacy of uptake of copper from any of the formulations. Formulation-dependent differences in the mechanism of copper uptake is suggested because rinsing of exposed shoots with dilute acid (0.01N HNO3) removed copper from shoots treated with CuSO4or Cu-TEA but not from those treated with Cu-EDA.


Sign in / Sign up

Export Citation Format

Share Document