Isozyme variation, morphology, and growth response to temperature in Pythium ultimum

1996 ◽  
Vol 74 (5) ◽  
pp. 753-761 ◽  
Author(s):  
D. J. S. Barr ◽  
S. I. Warwick ◽  
N. L. Désaulniers
Keyword(s):  
Growth Rate ◽  
Growth Response ◽  
Effective Means ◽  
Pythium Ultimum ◽  
Morphological Characters ◽  
Isozyme Analysis ◽  
Isozyme Variation ◽  
Different Temperatures ◽  
Isozyme Loci ◽  
Response To Temperature

A worldwide collection of 60 isolates of Pythium ultimum and 37 asexual (sexually sterile) isolates presumed to be P. ultimum were compared by isozyme analysis, morphological characters, and their growth rate at different temperatures. Isolates were separated into 10 multilocus genotypes as defined by nine isozyme loci. Five genotypes (U1–U5) comprising 85 isolates differed from each other merely by homo- or hetero-zygous states at one and (or) two loci. Four isolates in genotype U6 produced zoospores and were presumed to be var. sporangiiferum. They differed at one locus from genotypes U1–U5. Genotypes U7, U8, U9, and U10 differed from U1–U5 at one, two, three, and five loci, respectively. Sexual isolates occurred in genotypes U1–U3 and U6–U10, and asexual isolates in genotypes U2–U6. Only minor differences were detected in morphology in six isolates (genotypes U8–U10). A single isolate (genotype U10) differed in growth rate from all others. Isozyme analysis is an effective means of distinguishing P. ultimum from nine other species included for comparative purposes and for identifying asexual isolates that cannot be positively identified by morphology. Keywords: Pythium ultimum var. ultimum, Pythium ultimum var. sporangiiferum, isozymes.

Isozyme variation, morphology, and growth response to temperature in Pythium irregulare

1997 ◽  
Vol 75 (12) ◽  
pp. 2073-2081 ◽  
Author(s):  
D. J. S. Barr ◽  
S. I. Warwick ◽  
N. L. Desaulniers
Keyword(s):  
Growth Rate ◽  
Pythium Ultimum ◽  
Morphological Characters ◽  
Published Data ◽  
Pythium Irregulare ◽  
Analysis Group ◽  
Wide Range ◽  
Pythium Sylvaticum ◽  
Group A ◽  
Group B

Isozyme-based genetic diversity, morphological characters, and growth rate at different temperatures were compared in a worldwide collection of 125 isolates presumed to be Pythium irregulare Buisman. The isozyme data was analysed with previously published data for Pythium ultimum Trow and Pythium sylvaticum Campbell & Hendrix. UPGMA cluster analysis yielded a dendrogram with four distinct groups: P. ultimum, P. sylvaticum, and two for P. irregulare. Putative P. irregulare isolates were separated into 33 multilocus genotypes defined by 11 isozyme loci: group A contained 116 isolates in 25 genotypes, and group B, 8 isolates in 7 genotypes. One genotype with a single isolate was determined as P. sylvaticum. Based on the isozyme analysis, group B was considered a distinct taxonomic entity from group A, but lacked any unique morphological character. There was a wide range in oogonium and oospore sizes among different isolates of P. irregulare, with those in group B generally being larger. Some isolates in group A had well developed oogonial spines, but others were essentially spineless, whereas all those in group B were spineless. Both groups A and B contained isolates with distinctly aplerotic oospores and others with essentially plerotic oospores. Antheridial number and shape were highly variable both within and among isolates in the two groups. Growth rate over a range of temperatures varied among isolates in both groups and was not a reliable taxonomic criterion. The irregular shape of oogonia and, when present, oogonial spines were the only reliable characters for distinguishing P. irregulare isolates from other taxa. Key words: taxonomy, Oomycetes, Pythiaceae, Pythium ultimum, Pythium sylvaticum.

Isozyme variation in heterothallic species and related asexual isolates of Pythium

1997 ◽  
Vol 75 (11) ◽  
pp. 1927-1935 ◽  
Author(s):  
D. J. S. Barr ◽  
S. I. Warwick ◽  
N. L. Désaulniers
Keyword(s):  
Effective Means ◽  
Pythium Ultimum ◽  
Isozyme Analysis ◽  
Group Method ◽  
Published Data ◽  
Arithmetic Average ◽  
Pair Group ◽  
Pythium Splendens ◽  
Pythium Sylvaticum ◽  
Heterothallic Species

A collection of 63 heterothallic and asexual (sexually sterile) isolates were compared by isozyme analysis, vegetative characters, and their ability to produce oospores in paired cultures. The collection included isolates identified as Pythium heterothallicum, Pythium intermedium, Pythium macrosporum, Pythium splendens, Pythium sylvaticum, and Pythium tracheiphilum, and several unidentified isolates. Isolates were separated into 41 multilocus genotypes as defined by 11 isozyme loci. The data were analyzed with previously published data for Pythium ultimum, and dendrograms were obtained from unweighted pair-group method, arithmetic average cluster analysis. Forty-six genotypes (including nine of P. ultimum) grouped into seven clusters and three solitary genotypes. Six clusters contained known isolates of the aforementioned species and the seventh contained P. ultimum. Isolates within both the P. heterothallicum and P. sylvaticum clusters produced oospores when grown in paired cultures. Two of three isolates in the P. splendens cluster produced oospores, but none of the isolates in the P. intermedium and P. macrosporum clusters produced oospores when grown in pairs. Genotypes belonging to the P. intermedium cluster separated into two sister groups that had morphologically different vegetative bodies. There were no consistent vegetative characteristics to distinguish the species P. macrosporum, P. heterothallicum, and P. sylvaticum. Isozyme analysis provides an effective means of identifying Pythium species that do not readily produce oospores in culture. Key words: Pythium heterothallicum, Pythium intermedium, Pythium macrosporum, Pythium sylvaticum, Pythium splendens, Pythium tracheiphilum.

scholarly journals Differential Germination and Growth Response to Temperature of Three Ambrosia Weed Species—Implications for Future Spread

2020 ◽  
Vol 2 ◽  
Author(s):  
Yifat Yair ◽  
Yaakov Goldwasser ◽  
Moshe Sibony ◽  
Hanan Eizenberg ◽  
Baruch Rubin
Keyword(s):  
Growth Response ◽  
Plant Traits ◽  
Soil Surface ◽  
Combined Effects ◽  
Weed Species ◽  
Temperature Regimes ◽  
Different Temperatures ◽  
Rhizome Biomass ◽  
Response To Temperature ◽  
Germination And Growth

Three main Ambrosia species (Ragweed) grow in Israel; the most abundant invasive Ambrosia confertiflora DC, whereas A. artemisiifolia L. and A. tenuifolia Spreng., are of restricted distribution. The present research was aimed to study the effect of temperatures regimes on the development and growth of these Ambrosia species, to elucidate the environmental conditions and plant traits that affect their growth and infestation patterns. All three Ambrosia species germinate best in light from the soil surface with no prerequisite of a stratification period. A. confertiflora seed emergence is inhibited at high temperature regimes (28/34°C). A. artemisiifolia at low temperature regimes (10/16°C), while A. tenuifolia is less affected by the temperature regimes. A. confertiflora plant height increases with increasing temperatures, and at lower temperatures develops a rosette. Root and rhizome biomass were less affected by the different temperatures regimes; A. artemisiifolia aboveground mass was not affected by temperature regimes while A. tenuifolia aboveground mass was reduced only at lower temperatures. A. confertiflora fast invasion and establishment are due to the combined effects of prolific seed dispersal, rapid sprouting and growth, and its phenotypic plasticity.

scholarly journals Effects of light intensity and temperature on Cylindrospermopsis raciborskii (Cyanobacteria) with straight and coiled trichomes: growth rate and morphology

2012 ◽  
Vol 72 (2) ◽  
pp. 343-351 ◽  
Author(s):  
MC. Bittencourt-Oliveira ◽  
B. Buch ◽  
TC. Hereman ◽  
JDT. Arruda-Neto ◽  
AN. Moura ◽  
...  
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Morphological Changes ◽  
Population Control ◽  
Distinct Species ◽  
Cylindrospermopsis Raciborskii ◽  
Climatic Chamber ◽  
Light Intensities ◽  
Different Temperatures ◽  
Lower Temperature

Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju (Ordem Nostocales) is one of the most troublesome bloom-forming species in Brazil. Understanding the population dynamics of the different morphotypes of C. raciborskii (straight and coiled) could assist in the prediction of favourable conditions for the proliferation of this potentially toxin-producing species. The aim of the present study was to assess the effects of two different light intensities and temperatures on the growth rate and morphology of the trichomes of the straight and coiled morphotypes. For such, two non-toxin producing strains of C. raciborskii were used - one with a coiled trichome (ITEP31) and another with a straight trichome (ITEP28). The strains were cultured in BG-11 medium in a climatic chamber under controlled conditions. Two light intensities (30 and 90 µmol.m-2.s-1 ) were combined at temperatures of 21 and 31 °C and the growth rate and morphological changes were analysed. The morphotypes responded differently to the different temperatures and light intensities. Both strains exhibited faster growth velocities when submitted to higher light intensity and temperature. The lower temperature and higher luminosity hampered the development of both strains. Variations in cellular morphology and an absence of akinetes in both strains were related to the lower temperature (21 °C). The coiled morphotype demonstrated considerable phenotype plasticity, changing the morphology of trichome throughout its growth curve. Although molecular analysis does not sustain the separation of the morphotypes as distinct species, their different eco-physiological responses should be considered further knowledge of extreme importance for the population control of these potentially toxic organisms.

scholarly journals Characteristics оf growth and fluorescence оf certain types оf algae under acclimation to different temperatures under conditions оf cultures

2019 ◽  
Vol 59 (3) ◽  
pp. 347-359
Author(s):  
A. I. Akimov ◽  
E. S. Solomonova
Keyword(s):  
Growth Rate ◽  
Positive Temperature ◽  
Tolerance Zone ◽  
Lower Growth ◽  
Culture Collections ◽  
Thermal Growth ◽  
Different Temperatures ◽  
Temperature Rate ◽  
Relative Variable ◽  
Stable Growth

The temperature rate growth dependence and the relative variable fluorescence, (Fv/Fm) of some of marine planktonic algae from the culture collections were investigated. The algae optima temperature growth (Topt), upper and lower limits tolerant zone of species, and in some cases, changes in the dynamics of these parameters outside the tolerance zone were determined. The similarity of species temperature characteristics with vegetation conditions these species in the nature was observed. Prolonged stress exposure to low positive temperature (4–6°C) was reversible; recovery of the growth rate and Fv/Fm was observed immediately after the increase of temperature. At temperatures above Topt on 2–3°C for diatoms was observed gradual degradation of culture, which, depending on the duration of exposure can lead to the death of the algae. Dinoflagellate species of the summer growing season had higher temperature resistance, and remained viable at temperatures above 5–8°C high Topt, due to lower growth rates. Rising part temperature dependence of the rate of growth approximated by a linear relation, the regression coefficient is 0.08–0.13 for diatoms and 0.03–0.11 for dinophyte. The normalized values for this parameter (the relative value of change in the growth rate, %) was 5.3±0.4 for diatoms and 6.4±0.5 for dinophyte at 1°C of temperature change. For dinophyte species were also been observed larger values of the parameter Q10. The value Fv/Fm for most species had high values in the whole temperature range, in which maintained a stable growth of algae. The fall of this parameter was observed in increasing the border of tolerance zone, and was associated with inhibition of thermal growth processes.

Preparation and Swelling Dynamics Characterization of Poly(N, N-Diethylacrylamide-Co-Itaconic Acid) Intelligent Hydrogels

2012 ◽  
Vol 490-495 ◽  
pp. 3382-3386
Author(s):  
Xiao Qi Li ◽  
Nai Yan Zhang ◽  
Jun Hai Zhang
Keyword(s):  
Itaconic Acid ◽  
Monomer Concentration ◽  
Molar Ratio ◽  
Solution Temperature ◽  
Temperature Changes ◽  
Different Temperatures ◽  
Total Monomer Concentration ◽  
Equilibrium Swelling Ratio ◽  
Composition Ratios ◽  
Response To Temperature

Poly(N,N-diethylacrylamide) (PDEA) hydrogel is known for their intelligent reversible swelling/deswelling behavior in response to temperature changes across a lower critical solution temperature (LCST) at around 31oC. In this study, itaconic acid (IA) was co-polymerized with N, N-diethylacrylamide (DEA) monomer to improve the swelling behavior and the total absorbing water. These copolymer hydrogels were prepared by changing the initial DEA/IA molar ratio and total monomer concentration. The chemical structure of hydrogels was characterized by fourier transform infrared (FTIR) spectroscopy. In comparison with the PDEA hydrogel, the equilibrium swelling ratio (ESR) of the hydrogels increase with the increase of IA content in the feed and the swelling dynamics behaviors of the different composition ratios of the P(DEA-co-IA) hydrogels on the different temperatures was investigated in detail.

Does growth rate affect diatom compositional response to temperature?

Phycologia ◽  
2021 ◽  
pp. 1-11
Author(s):  
Anxhela Hania ◽  
Meri Eichner ◽  
Alessandra Norici ◽  
Ondřej Prášil ◽  
Mario Giordano
Keyword(s):  
Growth Rate ◽  
Response To Temperature

scholarly journals Performance of fat snook juveniles reared at different temperatures

2018 ◽  
Vol 40 (1) ◽  
pp. 39766
Author(s):  
Daniel Correia ◽  
Luiz Henrique Castro David ◽  
Sara Mello Pinho ◽  
João Costa-Filho ◽  
Maurício Gustavo Coelho Emerenciano ◽  
...  
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Specific Growth ◽  
Survival Rates ◽  
Feeding Rates ◽  
Feed Conversion ◽  
Final Weight ◽  
Different Temperatures ◽  
Water Recirculation ◽  
Fat Snook

We aimed at evaluating the effects of different water temperatures on the zootechnical performance of fat snook. The experiment lasted for 60 days, which was conducted in water recirculation systems, and was randomly designed with three treatments and three replicates each, corresponding to three water temperatures (25, 28 and 31°C). A total of 225 fat snook juveniles with a mean weight of 6.45 ± 0.58 g were used, which were fed daily until apparent satiety. Zootechnical parameters were assessed and feeding rates were registered for each tested temperature. Survival rates varied from 96 to 100% among treatments. Higher values of standard and total length, and weight gain were found in 28 and 31°C (p < 0.05). With regard to final weight, final biomass, feed conversion and specific growth rate, no significant differences were observed (p > 0.05). Feeding rates did not differ among evaluated temperatures. The results show that the used temperatures did not negatively affect zootechnical performance of fat snook juveniles. 

Growth Kinetics of Salmonella Isolates in a Laboratory Medium as Affected by Isolate and Holding Temperature†

1998 ◽  
Vol 61 (8) ◽  
pp. 964-968 ◽  
Author(s):  
THOMAS P. OSCAR
Keyword(s):  
Growth Rate ◽  
Stationary Phase ◽  
Growth Kinetics ◽  
Brain Heart Infusion ◽  
Lag Time ◽  
Culture Collection ◽  
Subsequent Growth ◽  
Laboratory Medium ◽  
Different Temperatures ◽  
Holding Temperature

Salmonella isolates were surveyed for their growth kinetics in a laboratory medium for the purpose of identifying isolates suitable for modeling experiments. In addition, the effect of holding stationary phase Salmonella cultures at different temperatures on their subsequent growth kinetics was evaluated for the purpose of developing a protocol to prevent the need for midnight sampling in modeling experiments. In Experiment 1, 16 isolates of Salmonella, 2 from the American Type Culture Collection (ATCC) and 14 from broiler operations, were surveyed for their growth kinetics in brain heart infusion (BHI) broth at 40°C. Lag time (P = 0.005) and growth rate (P = 0.022) were affected by identity of the isolate. Lag time ranged from 0.73 to 1.38 h, whereas growth rate ranged from 0.78 to 0.94 log10 CFU/ml/h. Overall, isolate S1 (Salmonella infantis from ATCC) was the fastest growing. In Experiment 2, 4 isolates of Salmonella, 1 from ATCC and 3 from broiler operations, were used to determine whether holding temperature influences subsequent growth kinetics. Salmonella isolates were grown to stationary phase at 37°C in BHI and then held for 24 h at 5, 22, or 37°C before dilution and reinitiation of growth in BHI at 37°C. Holding temperature did not alter or interact with identity of the isolate to alter subsequent growth kinetics. From the latter finding, a protocol was devised in which a dual-flask system is used to prevent the need for midnight sampling in modeling experiments. Similar to the results obtained in Experiment 1, identity of the isolate had only minor effects on growth kinetics in Experiment 2 indicating that all isolates examined were suitable for modeling experiments.

Growth ofKochia scoparia, Salsola iberica, andTriticum aestivumvaries with temperature

Weed Science ◽  
1999 ◽  
Vol 47 (4) ◽  
pp. 435-439 ◽  
Author(s):  
Cathy A. Nord ◽  
Calvin G. Messersmith ◽  
John D. Nalewaja
Keyword(s):  
Weed Management ◽  
Growth Response ◽  
Management Practices ◽  
Fresh Weight ◽  
Herbicide Application ◽  
Kochia Scoparia ◽  
Optimum Time ◽  
Influence Of Temperature On ◽  
Response To Temperature ◽  
Salsola Iberica

Information on the influence of temperature on growth of springTriticum aestivumL. (wheat) relative toKochia scoparia(L.) Schrad. (kochia) andSalsola ibericaSennen and Pau (Russian thistle) could lead to more efficient weed management practices. An experiment was conducted to determine the growth of springT. aestivum, K. scoparia, andS. ibericaat 15, 23, and 30 C in growth chambers. Fresh weight at 15 C was greater for springT. aestivumthan forK. scopariaandS. iberica.Conversely, fresh weights at 23 or 30 C were greater forK. scopariaandS. ibericathan for springT. aestivum.Growth response to temperature is consistent with the physiological characteristics for photosynthesis of springT. aestivum, a C3plant, andK. scopariaandS. iberica, which are C4plants. The results indicate that cool temperatures that usually occur for early-seeded springT. aestivumwould give springT. aestivumthe competitive advantage overK. scopariaorS. iberica.Additionally, growing degree day (GDD) equations for height development ofK. scopariaandS. ibericawere determined and could be used to determine the optimum time for postemergence herbicide application.

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