scholarly journals Effects of Mefenoxam, Phosphonate, and Paclobutrazol on In Vitro Characteristics of Phytophthora cactorum and P. citricola and on Canker Size of European Beech

Plant Disease ◽  
2009 ◽  
Vol 93 (7) ◽  
pp. 741-746 ◽  
Author(s):  
Jerry E. Weiland ◽  
Angela H. Nelson ◽  
George W. Hudler
Keyword(s):  
Plant Growth Regulator ◽  
Radial Growth ◽  
Preventive Treatment ◽  
European Beech ◽  
Phytophthora Cactorum ◽  
Northeastern United States ◽  
Single Spore ◽  
Inhibition Of Growth ◽  
Species Effect

Phytophthora citricola and P. cactorum cause bleeding cankers that lead to the death of mature European beech (Fagus sylvatica) in the northeastern United States. The effects of two fungicides and a plant growth regulator on in vitro pathogen characteristics and on canker expansion were investigated. In the first experiment, 16 single-spore isolates (11 P. citricola and 5 P. cactorum) were grown on clarified V8 juice agar amended with (i) 0 to 20 μg a.i./ml of mefenoxam, (ii) 0 to 301,429 μg a.i./ml phosphonate either with or without a bark-penetrating surfactant at 0.5 mg a.i./ml, or (iii) 0 to 25 mg a.i./ml of the surfactant alone. Radial growth, oospore production, and zoospore germination were observed to be dependent on isolate and treatment. A species effect on growth was also observed, as P. cactorum isolates were 2.5- to sevenfold less sensitive to phosphonate, but 2- to 150-fold more sensitive to mefenoxam than P. citricola isolates (based on 50% inhibition of growth). In the second experiment, bark and soil drenches of mefenoxam (50 mg a.i./ml and 19 μg a.i./ml, respectively), phosphonate (301,429 and 101 μg a.i./ml, respectively), and a soil drench of paclobutrazol (21 mg a.i./ml) were evaluated for their efficacy as curative or preventive treatments against bleeding canker. None of the treatments (curative or preventive) were able to stop canker expansion or prevent infection. However, saplings inoculated with P. citricola and treated with the phosphonate bark drench as either a curative or preventive treatment had cankers that were 36 to 82% shorter than those of inoculated control stems treated with water. For saplings inoculated with P. cactorum, the phosphonate bark drench was only effective when applied as a preventive (38% shorter than inoculated control stems treated with water), and not as a curative treatment. No other treatment was effective at limiting canker expansion.

scholarly journals In Vitro Fungicide Sensitivity of Rhizoctonia and Waitea Isolates Collected from Turfgrasses

2014 ◽  
Vol 32 (3) ◽  
pp. 126-132 ◽  
Author(s):  
Bimal S. Amaradasa ◽  
Dilip Lakshman ◽  
David S. McCall ◽  
Brandon J. Horvath
Keyword(s):  
Radial Growth ◽  
Geographic Origin ◽  
Fungicide Sensitivity ◽  
Disease Symptoms ◽  
Anastomosis Groups ◽  
Inhibition Of Growth ◽  
Variable Sensitivity ◽  
Moderate Sensitivity ◽  
Waitea Circinata

Different Rhizoctonia species and anastomosis groups (AGs) have been reported to show variable sensitivity to commercial fungicides. Thirty-six isolates of Rhizoctonia collected from turfgrasses were tested in vitro for sensitivity to commercial formulations of iprodione, triticonazole, and pyraclostrobin. Tested isolates represented R. solani AG 1-IB and AG 2-2IIIB; W. circinata varieties zeae (Wcz) and circinata (Wcc); and binucleate Rhizoctonia-like fungi (BNR) from different locations in Virginia and Maryland. Each fungicide was added to PDA medium to obtain concentrations at 0, 0.1, 1, 10 and 100 mg a.i.·L−1 (0.00001, 0.0001, 0.001 and 0.01 oz a.i.·gal−1). A mycelium plug from each isolate was grown on these plates. The fungicide concentration needed for 50% inhibition of radial growth (EC50) was determined for each isolate by fungicide combination. Waitea circinata isolates were moderately sensitive (EC50 = 1 to 10 mg a.i.·L−1) (0.0001 to 0.001 oz a.i.·gal−1) to iprodione while isolates of R. solani and BNR were extremely sensitive (EC50 < 1 mg a.i.·L−1). Isolates of AG 2-2IIIB exhibited less sensitivity to triticonazole (mean EC50 = 1.26 mg a.i.·L−1) than AG 1-IB and W. circinata (mean EC50 = 0.2, and 0.06 mg a.i.·L−1, respectively). BNR isolates varied in inhibition of growth by triticonazole, exhibiting extreme to moderate sensitivity. Isolates of W. circinata were moderately sensitive to pyraclostrobin while most cultures of R. solani and BNR were extremely sensitive. Geographic origin of isolates had no influence on the level of fungicide sensitivity. This study demonstrates the importance of accurately identifying the Rhizoctonia pathogen causing disease symptoms on a turfgrass for choosing an effective fungicide.

PENGEMBANGAN TEKNOLOGI SELEKSI IN VITRO BERULANG (REPEAT CYCLING–IN VITRO SELECTION) TOLERAN STRES KEKERINGAN UNTUK PERBAIKAN MUTU GENETIK DAN PRODUKSI TANAMAN KEDELAI BERMIKORIZA

2017 ◽  
Vol 1 (1) ◽  
pp. 74-84
Author(s):  
Ahmad Riduan ◽  
Rainiyati Rainiyati ◽  
Yulia Alia
Keyword(s):  
Arbuscular Mycorrhizae ◽  
In Vitro Selection ◽  
Soil Samples ◽  
Single Spore ◽  
Isolation And Characterization ◽  
Single Spore Culture ◽  
Spore Culture ◽  
Glomus Sp

Every plant rhizospheres in any ecosystem there are various living microorganisms including Arbuscular Mycorrhizae Fungi (AMF).  An isolation and characterization is required to investigate the species or type of the AMF. This research was aimed at studying the isolation and characterization of AMF sporulation in soybean rhizospheres in Jambi Province. The results of evaluation on soil samples before trapping showed that there are spores from three genus of AMF twelve types Glomus , two types Acaulospora and one type of Enthrophospora.  Following single spore culture in soybean rhizosphere, 5 spore types were obtained:  Glomus sp-1, Glomus sp-4, Glomus sp-7, Glomus sp-8 Glomus sp-10.

scholarly journals How Does Radial Growth of Water-Stressed Populations of European Beech (Fagus sylvatica L.) Trees Vary under Multiple Drought Events?

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Tamalika Chakraborty ◽  
Albert Reif ◽  
Andreas Matzarakis ◽  
Somidh Saha
Keyword(s):  
Soil Water ◽  
Fagus Sylvatica ◽  
Tree Growth ◽  
Radial Growth ◽  
Basal Area ◽  
European Beech ◽  
Canopy Openness ◽  
Fagus Sylvatica L ◽  
The Impact ◽  
Neighborhood Competition

European beech (Fagus sylvatica L.) trees are becoming vulnerable to drought, with a warming climate. Existing studies disagree on how radial growth varies in European beech in response to droughts. We aimed to find the impact of multiple droughts on beech trees’ annual radial growth at their ecological drought limit created by soil water availability in the forest. Besides, we quantified the influence of competition and canopy openness on the mean basal area growth of beech trees. We carried out this study in five near-natural temperate forests in three localities of Germany and Switzerland. We quantified available soil water storage capacity (AWC) in plots laid in the transition zone from oak to beech dominated forests. The plots were classified as ‘dry’ (AWC < 60 mL) and ‘less-dry’ (AWC > 60 mL). We performed dendroecological analyses starting from 1951 in continuous and discontinuous series to study the influence of climatic drought (i.e., precipitation-potential evapotranspiration) on the radial growth of beech trees in dry and less-dry plots. We used observed values for this analysis and did not use interpolated values from interpolated historical records in this study. We selected six drought events to study the resistance, recovery, and resilience of beech trees to drought at a discontinuous level. The radial growth was significantly higher in less-dry plots than dry plots. The increase in drought had reduced tree growth. Frequent climatic drought events resulted in more significant correlations, hence, increased the dependency of tree growth on AWC. We showed that the recovery and resilience to climatic drought were higher in trees in less-dry plots than dry plots, but it was the opposite for resistance. The resistance, recovery, and resilience of the trees were heterogeneous between the events of drought. Mean growth of beech trees (basal area increment) were negatively impacted by neighborhood competition and positively influenced by canopy openness. We emphasized that beech trees growing on soil with low AWC are at higher risk of growth decline. We concluded that changes in soil water conditions even at the microsite level could influence beech trees’ growth in their drought limit under the changing climate. Along with drought, neighborhood competition and lack of light can also reduce beech trees’ growth. This study will enrich the state of knowledge about the ongoing debate on the vulnerability of beech trees to drought in Europe.

scholarly journals Polymorphisms in Plasmodium falciparum dihydropteroate synthetase and dihydrofolate reductase genes in Nigerian children with uncomplicated malaria using high-resolution melting technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adeyemi T. Kayode ◽  
Fehintola V. Ajogbasile ◽  
Kazeem Akano ◽  
Jessica N. Uwanibe ◽  
Paul E. Oluniyi ◽  
...  
Keyword(s):  
High Resolution ◽  
Dihydrofolate Reductase ◽  
Uncomplicated Malaria ◽  
High Resolution Melting ◽  
Intermittent Preventive Treatment ◽  
Preventive Treatment ◽  
Triple Mutant ◽  
Seasonal Malaria Chemoprevention

AbstractIn 2005, the Nigerian Federal Ministry of Health revised the treatment policy for uncomplicated malaria with the introduction of artemisinin-based combination therapies (ACTs). This policy change discouraged the use of Sulphadoxine-pyrimethamine (SP) as the second-line treatment of uncomplicated falciparum malaria. However, SP is used as an intermittent preventive treatment of malaria in pregnancy (IPTp) and seasonal malaria chemoprevention (SMC) in children aged 3–59 months. There have been increasing reports of SP resistance especially in the non-pregnant population in Nigeria, thus, the need to continually monitor the efficacy of SP as IPTp and SMC by estimating polymorphisms in dihydropteroate synthetase (dhps) and dihydrofolate reductase (dhfr) genes associated with SP resistance. The high resolution-melting (HRM) assay was used to investigate polymorphisms in codons 51, 59, 108 and 164 of the dhfr gene and codons 437, 540, 581 and 613 of the dhps gene. DNA was extracted from 271 dried bloodspot filter paper samples obtained from children (< 5 years old) with uncomplicated malaria. The dhfr triple mutant I51R59N108, dhps double mutant G437G581 and quadruple dhfr I51R59N108 + dhps G437 mutant haplotypes were observed in 80.8%, 13.7% and 52.8% parasites, respectively. Although the quintuple dhfr I51R59N108 + dhps G437E540 and sextuple dhfr I51R59N108 + dhps G437E540G581 mutant haplotypes linked with in-vivo and in-vitro SP resistance were not detected, constant surveillance of these haplotypes should be done in the country to detect any change in prevalence.

scholarly journals Sensitivity of Mycosphaerella fijiensis from Banana to Trifloxystrobin

Plant Disease ◽  
2001 ◽  
Vol 85 (12) ◽  
pp. 1264-1270 ◽  
Author(s):  
K. M. Chin ◽  
M. Wirz ◽  
D. Laird
Keyword(s):  
Cross Resistance ◽  
In Vitro Tests ◽  
Mycosphaerella Fijiensis ◽  
In Planta ◽  
Baseline Sensitivity ◽  
Single Spore ◽  
Resistance Factors ◽  
Development Site ◽  
Disease Pressure

An ascospore germination method was developed and validated to assess the sensitivity of bulk samples of Mycosphaerella fijiensis to trifloxystrobin. Using this method, the sensitivity of 142 ascospore samples from banana plantations not treated with strobilurins was analyzed to establish a baseline of pathogen sensitivity. A bulk method was utilized for monitoring purposes because it avoids potential complications due to the isolation and propagation of single-spore isolates and enables the testing of larger samples. Following intensive use of strobilurins (6 to 11 applications per year) over 4 years, under conditions of high disease pressure and the absence of sanitary measures at a development site in Costa Rica, bulk samples with 50% effective concentration (EC50) resistance factors (RFs) in excess of 500 compared with the mean baseline sensitivity were detected. Single-ascospore isolates derived from spores germinating at the discriminatory dose of 3 μg/ml were also resistant, suggesting that the frequency of resistant individuals in bulk samples could be estimated from the relative numbers of ascospores growing at this dose. The resistance of selected isolates was confirmed in planta. In vitro tests with four resistant and two sensitive single-ascospore isolates collected from different locations and times indicated possible cross-resistance of trifloxystrobin to azoxystrobin, famoxadone, and fenamidone, but not to propiconazole.

Inhibition of Growth of Breast Cancer in Vitro by the Ribosome-Inactivating Protein Saporin 6

1991 ◽  
pp. 625-629
Author(s):  
L. Roncuzzi ◽  
A. Gasperi-Campani ◽  
W. Zoli ◽  
A. Volpi ◽  
D. Amadori
Keyword(s):  
Breast Cancer ◽  
Ribosome Inactivating Protein ◽  
Inhibition Of Growth

scholarly journals EFFECT OF DIFFERENT SOURCES OF PLANT GROWTH REGULATOR ON THE INDUCTION AND DEVELOPMENT OF MANGOSTEEN SOMATIC EMBRYOS

2017 ◽  
Vol 17 (1) ◽  
pp. 9
Author(s):  
Yosi Zendra Joni ◽  
Riry Prihatini ◽  
Darda Efendi ◽  
Ika Roostika
Keyword(s):  
Somatic Embryogenesis ◽  
Plant Growth ◽  
Embryogenic Callus ◽  
Plant Growth Regulator ◽  
Somatic Embryos ◽  
Casein Hydrolysate ◽  
Malt Extract ◽  
Mass Propagation ◽  
Embryogenic Callus Induction

<p>Somatic embryogenesis is a technique for regenerating embryos derived from somatic cells of various plant species. This technique along with the utilization of plant growth regulator (PGR) might benefit for mass propagation and improvement of plant species through biotechnological tools. The study aimed to determine the effect of different plant growth regu-lators, namely 6-benzyladenine (BA) and thidiazuron (TDZ) on the embryogenic callus induction as well as casein hydrolysate and malt extract on the somatic embryo development of mangosteen. The explants used were in vitro young stems of mangosteen clone Leuwiliang. This study consisted of two experiments, namely induction of embryogenic callus and formation of somatic embryo. The first experiment was arranged as factorial in a completely randomized design with BA (0 and 0.7 mg l-1) as the first factor and TDZ (0, 0.1, 0.5 and 1.0 mg l-1) as the second factor. The second experiment consisted of four treatments, i.e. casein hydrolysate and malt extract at the rate of 500 and 1,000 mg l-1. The results showed that the best medium for embryogenic callus induction was MS supplemented with 0.1 mg l-1 TDZ, which resulted semifriable calli. Casein hydrolysate and malt extract could not induce the formation of somatic embryos. After two times subcultures on the same MS medium supplemented with 0.5 mg l-1 TDZ and 0.7 mg l-1 BA, a total of 33.8 somatic embryos per explant was induced. The successful somatic embryogenesis would support mangosteen breeding and in vitro mass propagation program.</p>

scholarly journals In Vitro Antagonistic Study of Maize Root Colonizing Fungal Isolates Against Fusarium moniliforme Causing Ear Rot Disease of Maize

2021 ◽  
Vol 11 (2) ◽  
pp. 133-139
Author(s):  
Parimal Mandal ◽  
◽  
Zerald Tiru ◽  
Monalisha Sarkar ◽  
Arka Chakroborty ◽  
...  
Keyword(s):  
Trichoderma Harzianum ◽  
Radial Growth ◽  
Culture Collection ◽  
Maize Root ◽  
Trichoderma Asperellum ◽  
Ear Rot ◽  
Growth Promoters ◽  
Fungal Isolates ◽  
Plant Growth Promoting

In the present study, different root colonizing fungal isolates were isolated from the rhizospheric soil of maize growing areas of Uttar Dinajpur, West Bengal. All the isolates including test pathogen were identified from Indian Type Culture Collection, New Delhi. Plant growth promoting maize root colonizing fungal isolates- Penicillium pinophilum (ITC NO. 11,201.19), Trichoderma harzianum (ITC NO.11,203.19), Trichoderma asperellum (ITC NO. 11,209.19), Aspergillus niger (ITC NO. 11,204.19) and Penicillum purpurogenum (ITC NO. 11,207.19) exhibited antagonistic activities against F. moniliforme (ITC NO. 11,208.19) in vitro. Two antagonistic isolates of T. harzianum and eleven strains of T. asperellum showed antibiosis mechanism for antagonism against F. moniliforme with the range of Percent Inhibition of Radial Growth from 62.41% to 88.57%. Competitive mode of antagonism against test pathogen by the isolates of P. pinophilum, P. purpurogenum and six isolates of A. niger were found. Percent of inhibition of radial growth ranged from 57.14% to 91.42%. In our finding, antagonistic isolates especially Trichoderma harzianum (ITC NO. 11,203.19), Trichoderma asperellum (ITC NO. 11,209.19) strains either single or in combination with rest maize root colonizing strains could be used as potent growth promoters as well as biocontrol (BCA) agents.

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