scholarly journals Application of Gamma Induced Mutation in Breeding Potato for Bacterial Wilt Disease Resistance

2020 ◽  
pp. 28-38
Author(s):  
Emmy Chepkoech ◽  
Miriam Kinyua ◽  
Julius Ochuodho ◽  
Oliver Kiplagat ◽  
Souleymane Bado ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Crop Production ◽  
Solanum Tuberosum L ◽  
Control Measure ◽  
Yield Reduction ◽  
Broad Host Range ◽  
Full Potential ◽  
Pathogenicity Test ◽  
Dose Rates ◽  
Significant Difference

Aims: Potato (Solanum tuberosum L.) production in Kenya has not been achieved in its full potential due to susceptibility of potato varieties to pest and diseases among others. Bacterial wilt, caused by Ralstonia solanacearum in potato is regarded as an important disease contributing to significant yield reduction. The disease is considered more difficult to control in field crop production using universal control measure due to pathogen’s properties as a soil-borne bacterium, broad host range and the genetic variation level within the strains. The objective was to screen potato mutants at M1V4 mutant populations for resistance against bacterial wilt using pathogenicity test. Study Design: The experimental design used was an alpha lattice with twenty three blocks each having seven plots with three replications each. Data were subjected to analysis of variance using SAS statistical package, version 9.1 and mean separation done using Duncan Multiple Range Test (DMRT) whenever there were significant differences. Place and Duration of Study: The study was carried out at Kenya Agricultural Livestock and Research Organization (KALRO), Kabete station for one season (December 2015 to April 2016). Methodology: One hundred and sixty three mutants developed from three commercial varieties (Asante 72, Mpya 43 and Sherekea 47) were evaluated. Results: The reactions of potato mutants to bacterial wilt varied from variety to variety and mutants to mutants. None of the Asante, Mpya and Sherekea mutants used was found to be resistant to bacterial wilt though Asante mutant populations showed better response. There was significant difference in some traits such as DTOW, AUDPC and PSTTN across the three potato mutant populations. Conclusion: The variation within the potato mutants and response to bacterial wilt resistance levels could be attributed to different dose rates and the reaction of each variety to the mutagen used. Since mutation is random its effects are enormous.

scholarly journals Biocontrol Potential of Chitin and Chitosan Extracted from Black Soldier Fly Pupal Exuviae against Bacterial Wilt of Tomato

2022 ◽  
Vol 10 (1) ◽  
pp. 165
Author(s):  
Violah Jepkogei Kemboi ◽  
Carolyne Kipkoech ◽  
Moses Njire ◽  
Samuel Were ◽  
Mevin Kiprotich Lagat ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Disease Incidence ◽  
Molecular Techniques ◽  
Control Measures ◽  
Pathogenicity Test ◽  
Management Options ◽  
Black Soldier Fly ◽  
Pupal Exuviae ◽  
Significant Difference ◽  
Chitin And Chitosan

Globally, Ralstonia solanacearum (Smith) is ranked one of the most destructive bacterial pathogens inducing rapid and fatal wilting symptoms on tomatoes. Yield losses on tomatoes vary from 0 to 91% and most control measures are unaffordable to resource-poor farmers. This study investigated the antimicrobial activities of chitin and chitosan extracted from black soldier fly (BSF) pupal exuviae against R. solanacearum. Morphological, biochemical, and molecular techniques were used to isolate and characterize R. solanacearum for in vitro pathogenicity test using disc diffusion technique. Our results revealed that BSF chitosan significantly inhibited the growth of R. solanacearum when compared to treatments without chitosan. However, there was no significant difference in the antibacterial activities between BSF and commercial chitosan against R. solanacearum. Soil amended with BSF-chitin and chitosan demonstrated a reduction in bacterial wilt disease incidence by 30.31% and 34.95%, respectively. Whereas, disease severity was reduced by 22.57% and 23.66%, when inoculated tomato plants were subjected to soil amended with BSF chitin and chitosan, respectively. These findings have demonstrated that BSF pupal shells are an attractive renewable raw material for the recovery of valuable products (chitin and chitosan) with promising ability as a new type of eco-friendly control measure against bacterial wilt caused by R. solanacearum. Further studies should explore integrated pest management options that integrate multiple components including insect-based chitin and chitosan to manage bacterial wilt diseases, contributing significantly to increased tomato production worldwide.

A microfluidic device with integrated impedance detection for λ-DNA

2003 ◽  
Vol 773 ◽  
Author(s):  
Myung-Il Park ◽  
Jonging Hong ◽  
Dae Sung Yoon ◽  
Chong-Ook Park ◽  
Geunbae Im
Keyword(s):  
Microfluidic Device ◽  
Electrochemical Impedance ◽  
Direct Detection ◽  
Full Potential ◽  
Label Free ◽  
Buffer Solution ◽  
Detection Systems ◽  
Significant Difference ◽  
Detection Of Biomolecules ◽  
Impedance Magnitude

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.

scholarly journals The Effectiveness of Candidate Probiotic Bacteria to Control Vibriosis Disease

2017 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Mulyati Mulyati ◽  
Suryati Suryati ◽  
Irfani Baga
Keyword(s):  
Survival Rate ◽  
Sea Water ◽  
Challenge Test ◽  
Probiotic Bacteria ◽  
Pathogenicity Test ◽  
Inhibitory Ability ◽  
Significant Difference ◽  
Portunid Crab

The study aims to isolate, characterize, and examine probiotic bacteria's inhibitory ability against Vibrio harveyi bacteria, both in-vitro and in vivo. Methods used in the study consist of 1) An Isolation of Candidate Probiotic Bacteria, 2) An Antagonistic Test of Candidate Probiotic Bacteria in vitro, 3) An Identification of Bacteria, 4) A Pathogenicity Test of Candidate Probiotic Bacteria, 5) An Antagonistic Test of Candidate Probiotic Bacteria against V. harveyi in vivo. According to the isolation of candidate probiotic bacteria, there are 18 isolated candidate probiotic. After being tested for its inhibitory ability in vitro, there are 8 isolates with zone of inhibition as follows: isolate MM 7 from intestine (22 mm), isolate MM 6 from intestine (12 mm), isolate MM 10 from sea water (10 mm), isolate MM 5 from intestine (9 mm), isolate MM 4 from intestine (8 mm), isolate MM 3 from intestine (7 mm), isolate MM 2.2 from intestine (7 mm), isolate MM 2.1 from intestine (7 mm). Eight genera of the candidate probiotic bacteria is derived from Portunid crab, they are Staphylococcus, Streptococcus, bacillus, vibrio, Alcaligenes, Lactobacillus, micrococcus. Before proceeding the V. harveyi bacterial challenge test in vivo, three potential isolates consisting of MM6, MM7 and MM10 as the probiotic bacteria are pathogenicity-tested against V. harveyi. The survival rate of Portunid crab on pathogenicity test using MM6, MM7 and MM10 generates 91.11-100%, while the control generates 100% survival rate. Variance analysis result through post-hoc Tukey's Honest Significant Difference (HSD) test at 95% confidence interval indicates that isolate MM7 and MM10 are significantly able to increase hatchling Portunid crab's survival rate.

scholarly journals Antifungal Activity of Propyl Disulfide from Neem (Azadirachta indica) in Vapor and Agar Diffusion Assays against Anthracnose Pathogens (Colletotrichum gloeosporioides and Colletotrichum acutatum) in Mango Fruit

2021 ◽  
Vol 9 (4) ◽  
pp. 839
Author(s):  
Muhammad Rafiullah Khan ◽  
Vanee Chonhenchob ◽  
Chongxing Huang ◽  
Panitee Suwanamornlert
Keyword(s):  
Antifungal Activity ◽  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Colletotrichum Acutatum ◽  
Model Parameters ◽  
Pathogenicity Test ◽  
Agar Diffusion ◽  
Wide Range ◽  
Significant Difference ◽  
Diffusion Assay

Microorganisms causing anthracnose diseases have a medium to a high level of resistance to the existing fungicides. This study aimed to investigate neem plant extract (propyl disulfide, PD) as an alternative to the current fungicides against mango’s anthracnose. Microorganisms were isolated from decayed mango and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum. Next, a pathogenicity test was conducted and after fulfilling Koch’s postulates, fungi were reisolated from these symptomatic fruits and we thus obtained pure cultures. Then, different concentrations of PD were used against these fungi in vapor and agar diffusion assays. Ethanol and distilled water were served as control treatments. PD significantly (p ≤ 0.05) inhibited more of the mycelial growth of these fungi than both controls. The antifungal activity of PD increased with increasing concentrations. The vapor diffusion assay was more effective in inhibiting the mycelial growth of these fungi than the agar diffusion assay. A good fit (R2, 0.950) of the experimental data in the Gompertz growth model and a significant difference in the model parameters, i.e., lag phase (λ), stationary phase (A) and mycelial growth rate, further showed the antifungal efficacy of PD. Therefore, PD could be the best antimicrobial compound against a wide range of microorganisms.

scholarly journals Quantifying the impact of land degradation on crop production: the case of Senegal

Solid Earth ◽  
2016 ◽  
Vol 7 (1) ◽  
pp. 93-103 ◽  
Author(s):  
B. G. J. S. Sonneveld ◽  
M. A. Keyzer ◽  
D. Ndiaye
Keyword(s):  
Land Degradation ◽  
Crop Production ◽  
Crop Yields ◽  
Fertilizer Application ◽  
Yield Reduction ◽  
Sufficient Information ◽  
Persistent Problem ◽  
Confounding Variables ◽  
A Site ◽  
The Impact

Abstract. Land degradation has been a persistent problem in Senegal for more than a century and by now has become a serious impediment to long-term development. In this paper, we quantify the impact of land degradation on crop yields using the results of a nationwide land degradation assessment. For this, the study needs to address two issues. First, the land degradation assessment comprises qualitative expert judgements that have to be converted into more objective, quantitative terms. We propose a land degradation index and assess its plausibility. Second, observational data on soils, land use, and rainfall do not provide sufficient information to isolate the impact of land degradation. We, therefore, design a pseudo-experiment that for sites with otherwise similar circumstances compares the yield of a site with and one without land degradation. This pairing exercise is conducted under a gradual refining of the classification of circumstances, until a more or less stable response to land degradation is obtained. In this way, we hope to have controlled sufficiently for confounding variables that will bias the estimation of the impact of land degradation on crop yields. A small number of shared characteristics reveal tendencies of "severe" land degradation levels being associated with declining yields as compared to similar sites with "low" degradation levels. However, as we zoom in at more detail some exceptions come to the fore, in particular in areas without fertilizer application. Yet, our overall conclusion is that yield reduction is associated with higher levels of land degradation, irrespective of whether fertilizer is being applied or not.

scholarly journals The effect of methylphenidate-OROS® on the narrative ability of children with attention-deficit hyperactivity disorder

2017 ◽  
Vol 64 (1) ◽  
Author(s):  
Tessa L. Rausch ◽  
Diane L. Kendall ◽  
Sara T. Kover ◽  
Elizabeth M. Louw ◽  
Ursula L. Zsilavecz ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Stimulant Medication ◽  
Full Potential ◽  
Systematic Analysis ◽  
Children With Adhd ◽  
Cascading Effects ◽  
Hyperactivity Disorder ◽  
Significant Difference ◽  
Narrative Ability

Background and objective: Children with attention-deficit hyperactivity disorder (ADHD) experience difficulty with expressive language, including form (e.g. grammatical construction) and content (e.g. coherence). The current study aimed to investigate the effect of methylphenidate-Osmotic Release Oral System® (MPH-OROS®) on the narrative ability of children with ADHD and language impairment, through the analysis of microstructure and macrostructure narrative elements.Method: In a single group off–on medication test design, narratives were obtained from 12 children with ADHD, aged 7–13 years, using wordless picture books. For microstructure, number of words, type–token ratio and mean length of utterance were derived from narrative samples using Systematic Analysis of Language Transcripts conventions. For macrostructure, the narratives were coded according to the Narrative Scoring Scheme, which includes seven narrative characteristics, as well as a composite score reflecting the child’s overall narrative ability.Results: The administration of MPH-OROS® resulted in a significant difference in certain aspects of language macrostructure: cohesion and overall narrative ability. Little effect was noted in microstructure elements.Conclusion: We observed a positive effect of stimulant medication on the macrostructure, but not on the microstructure, of narrative production. Although stimulant medication improves attention and concentration, it does not improve all aspects of language abilities in children with ADHD. Language difficulties associated with ADHD related to language content and use may be more responsive to stimulant medication than language form, which is likely to be affected by cascading effects of inattention, hyperactivity and impulsivity beginning very early in life and to progress over a more protracted period. Therefore, a combination of treatments is advocated to ensure that children with ADHD are successful in reaching their full potential.

scholarly journals First Report of Stem and Foliage Blight of Chrysanthemum Caused by Phytophthora drechsleri in the United States

Plant Disease ◽  
2021 ◽  
Author(s):  
Charles Krasnow ◽  
Nancy Rechcigl ◽  
Jennifer Olson ◽  
Linus Schmitz ◽  
Steven N. Jeffers
Keyword(s):  
United States ◽  
South Carolina ◽  
Sequence Similarity ◽  
Morphological Characteristics ◽  
The United States ◽  
Universal Primers ◽  
Broad Host Range ◽  
Pathogenicity Test ◽  
First Report ◽  
Foliage Blight

Chrysanthemum (Chrysanthemum × morifolium) plants exhibiting stem and foliage blight were observed in a commercial nursery in eastern Oklahoma in June 2019. Disease symptoms were observed on ~10% of plants during a period of frequent rain and high temperatures (26-36°C). Dark brown lesions girdled the stems of symptomatic plants and leaves were wilted and necrotic. The crown and roots were asymptomatic and not discolored. A species of Phytophthora was consistently isolated from the stems of diseased plants on selective V8 agar (Lamour and Hausbeck 2000). The Phytophthora sp. produced ellipsoid to obpyriform sporangia that were non-papillate and persistent on V8 agar plugs submerged in distilled water for 8 h. Sporangia formed on long sporangiophores and measured 50.5 (45-60) × 29.8 (25-35) µm. Oospores and chlamydospores were not formed by individual isolates. Mycelium growth was present at 35°C. Isolates were tentatively identified as P. drechsleri using morphological characteristics and growth at 35°C (Erwin and Ribeiro 1996). DNA was extracted from mycelium of four isolates, and the internal transcribed spacer (ITS) region was amplified using universal primers ITS 4 and ITS 6. The PCR product was sequenced and a BLASTn search showed 100% sequence similarity to P. drechsleri (GenBank Accession Nos. KJ755118 and GU111625), a common species of Phytophthora that has been observed on ornamental and vegetable crops in the U.S. (Erwin and Ribeiro 1996). The gene sequences for each isolate were deposited in GenBank (accession Nos. MW315961, MW315962, MW315963, and MW315964). These four isolates were paired with known A1 and A2 isolates on super clarified V8 agar (Jeffers 2015), and all four were mating type A1. They also were sensitive to the fungicide mefenoxam at 100 ppm (Olson et al. 2013). To confirm pathogenicity, 4-week-old ‘Brandi Burgundy’ chrysanthemum plants were grown in 10-cm pots containing a peat potting medium. Plants (n = 7) were atomized with 1 ml of zoospore suspension containing 5 × 103 zoospores of each isolate. Control plants received sterile water. Plants were maintained at 100% RH for 24 h and then placed in a protected shade-structure where temperatures ranged from 19-32°C. All plants displayed symptoms of stem and foliage blight in 2-3 days. Symptoms that developed on infected plants were similar to those observed in the nursery. Several inoculated plants died, but stem blight, dieback, and foliar wilt were primarily observed. Disease severity averaged 50-60% on inoculated plants 15 days after inoculation. Control plants did not develop symptoms. The pathogen was consistently isolated from stems of symptomatic plants and verified as P. drechsleri based on morphology. The pathogenicity test was repeated with similar results. P. drechsleri has a broad host range (Erwin and Ribeiro 1996; Farr et al. 2021), including green beans (Phaseolus vulgaris), which are susceptible to seedling blight and pod rot in eastern Oklahoma. Previously, P. drechsleri has been reported on chrysanthemums in Argentina (Frezzi 1950), Pennsylvania (Molnar et al. 2020), and South Carolina (Camacho 2009). Chrysanthemums are widely grown in nurseries in the Midwest and other regions of the USA for local and national markets. This is the first report of P. drechsleri causing stem and foliage blight on chrysanthemum species in the United States. Identifying sources of primary inoculum may be necessary to limit economic loss from P. drechsleri.

scholarly journals The Effect of Abiotic Stresses on the Protein Composition of Four Hungarian Wheat Varieties

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Dalma Nagy-Réder ◽  
Zsófia Birinyi ◽  
Marianna Rakszegi ◽  
Ferenc Békés ◽  
Gyöngyvér Gell
Keyword(s):  
Abiotic Stress ◽  
Protein Content ◽  
Functional Properties ◽  
Crop Production ◽  
Global Climate ◽  
Protein Composition ◽  
Grain Protein Content ◽  
Wheat Varieties ◽  
Significant Difference ◽  
Negative Effect

Global climate change in recent years has resulted in extreme heat and drought events that significantly influence crop production and endanger food security. Such abiotic stress during the growing season has a negative effect on yield as well as on the functional properties of wheat grain protein content and composition. This reduces the value of grain, as these factors significantly reduce end-use quality. In this study, four Hungarian bread wheat cultivars (Triticum aestivum ssp. aestivum) with different drought and heat tolerance were examined. Changes in the size- and hydrophobicity-based distribution of the total proteins of the samples have been monitored by SE- and RP-HPLC, respectively, together with parallel investigations of changes in the amounts of the R5 and G12 antibodies related to celiac disease immunoreactive peptides. Significant difference in yield, protein content and composition have been observed in each cultivar, altering the amounts of CD-related gliadin, as well as the protein parameters directly related to techno-functional properties (Glu/Gli ratio, UPP%). The extent of changes largely depended on the timing of the abiotic stress. The severity of the negative effect depended on the growth stage in which abiotic stress occurred.

scholarly journals Agronomic research in Martonvásár, aimed at promoting the efficiency of field crop production

2012 ◽  
pp. 89-93
Author(s):  
Tamás Árendás ◽  
Zoltán Berzsenyi ◽  
Péter Bónis
Keyword(s):  
Regression Analysis ◽  
Grain Yield ◽  
Durum Wheat ◽  
Crop Production ◽  
Plant Protection ◽  
Sowing Date ◽  
Forest Residues ◽  
Sowing Dates ◽  
Significant Difference ◽  
Long Term Experiment

The effect of crop production factors on the grain yield was analysed on the basis of three-factorial experiments laid out in a split-split-plot design. In the case of maize the studies were made as part of a long-term experiment set up in 1980 on chernozem soil with forest residues, well supplied with N and very well with PK. The effects of five N levels in the main plots and four sowing dates in the subplots were compared in terms of the performance of four medium early hybrids (FAO 200). In the technological adaptation experiments carried out with durum wheat, the N supplies were moderate (2010) or good (2011), while the P and K supplies were good or very good in both years. Six N top-dressing treatments were applied in the main plots and five plant protection treatments in the subplots to test the responses of three varieties. The results were evaluated using analysis of variance, while correlations between the variables were detected using regression analysis.The effect of the tested factors on the grain yield was significant in the three-factorial maize experiment despite the annual fluctuations, reflected in extremely variable environmental means. During the given period the effect of N fertilisation surpassed that of the sowing date and the genotype. Regression analysis on the N responses for various sowing dates showed that maize sown in the middle 10 days of April gave the highest yield, but the N rates required to achieve maximum values declined as sowing was delayed. In the very wet year, the yield of durum wheat was influenced to the greatest extent by the plant protection treatments, while N supplies and the choice of variety were of approximately the same importance.  In the favourable year the yielding ability was determined by topdressing and the importance of plant protection dropped to half,  while no  significant difference could be detected between the tested varieties. According to the results of regression analysis, the positive effect of plant protection could not be substituted by an increase in the N rate in either year. The achievement of higher yields was only possible by a joint intensification of plant protection and N fertilisation. Nevertheless, the use of more efficient chemicals led to a slightly, though not significantly, higher yield, with a lower N requirement. 

scholarly journals Biocidal potential of Three Plant Extracts on Rhizopus stolonifer, Causal Organism of Irish Potato (Solanum tuberosum L.) Tuber Rot

2020 ◽  
Vol 5 (8) ◽  
pp. 774-779
Author(s):  
Chuku, E.C ◽  
Njoku, A.A ◽  
Nmom, F.W
Keyword(s):  
Plant Extracts ◽  
Severity Score ◽  
Solanum Tuberosum L ◽  
Curcuma Longa ◽  
Irish Potato ◽  
Citrus Limon ◽  
Aqueous Extracts ◽  
Rhizopus Stolonifer ◽  
Causal Organism ◽  
Significant Difference

Research study was carried out to assess the biocidal effect of aqueous extracts of Curcuma longa, Zingiber officinale, Citrus limon peel and synthetic fungicide Mancozeb against Rhizopus stolonifer using the poisoned food technique on PDA. Various concentrations (50, 75, and 100%) of extracts from the rhizomes of C. longa, Z. officinale, the peel of C. limon and Mancozeb (0.002%) significantly inhibited the mycelia growth of R. stolonifer after 3 days. Effects of the synthetic fungicide (Mancozeb) comparative to the plant extracts were also determined. Although the extracts showed varying degrees of antifungal efficacy, 100% concentration of Z. officinale (58.96%) proved to be more potent against R. stolonifer than the other plant extracts but was lower and significantly different when compared with Mancozeb (73.31%) at (P≤0.05) after 3 days. Extracts of C. longa and C. limon peel showed a lower inhibition level ranging from 45.01% to 56.98% and 9.57% to 18.73% respectively and were significantly different when compared with Mancozeb at (P≤0.05). Inhibition of fungal growth increased with a corresponding increase in extract concentration and days. The plant leaf extracts effectively inhibited the mycelial growth of pathogen in vitro after 3 days. In vivo study was carried out using spore suspensions of R. stolonifer. Fresh, healthy and surface sterilized Irish potato tubers were inoculated with 6.4 x 104 spores/ml and treated with aqueous extracts of C. longa, Z. officinale and C. limon peel after 24 hours. The result showed that all plant extracts had significant effect on disease severity in tubers inoculated with R. stolonifer. However, 100% concentration of Z. officinale gave the best rot reduction caused by R. stolonifer with severity score of 0.33 but it was not significantly different at (p<0.05) from mancozeb which had a severity score of 0.67. However, they were significantly different at (p<0.05) from the inoculated control (3.33). There were variations in weight loss but no significant difference was observed among the various treatment methods adopted.

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