scholarly journals The Effects of Endophytic Beauveria bassiana Inoculation on Infestation Level of Planococcus ficus, Growth and Volatile Constituents of Potted Greenhouse Grapevine (Vitis vinifera L.)

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 72 ◽  
Author(s):  
Siphokazi Moloinyane ◽  
Felix Nchu

Endophytic entomopathogenic fungi are being explored for the management of phytophagous insect pests. The effects of Beauveria bassiana (Hypocreales) inoculation of grape plants on the infestation level of P. ficus, tissue nutrient contents, and growth and volatile constituents of potted grape plants were assessed. Grapevine plants were individually inoculated with a suspension of 1 × 108 conidia mL−1 of B. bassiana by drenching before experimentally infesting each of them with thirty adult females of P. ficus. At four weeks post-treatment, the fungus was re-isolated from leaves of 50% of the fungus-exposed plants. However, no significant difference (p > 0.05) was observed in all the plant growth parameters measured in the fungus-treated and control plants. Plant tissue analysis revealed markedly higher contents of calcium (Ca) and magnesium (Mg) in the leaf tissue of plants exposed to the B. bassiana relative to the control. Gas chromatography mass spectrometry (GC-MS) analyses showed that a significantly (X2 = 5.1; p < 0.02) higher number of known anti-insect volatile compounds (nine) were present among fungus treated plants compared to the control plants (five). Naphthalene, which is toxic to insects and humans, was detected only in the volatiles of the fungus-exposed plants. B. bassiana did not have any significant effect on total polyphenol, alkaloid, and flavonoids. Overall, treatment with fungus did not inhibit the infestation by P. ficus. In conclusion, these findings shed light on some of the mechanisms involved in endophytic fungus-plant-insect interactions.

OENO One ◽  
2017 ◽  
Vol 51 (4) ◽  
pp. 343 ◽  
Author(s):  
Miguel Javier QUIROGA ◽  
Miguel Ángel OLEGO ◽  
Mario SÁNCHEZ-GARCÍA ◽  
Jesús Esteban MEDINA ◽  
Fernando VISCONTI ◽  
...  

Aims: Soil acidity decreases soil fertility and grapevine growth. Aluminum toxicity has been recognized as one of the most common causes of reduced grape yields in acid vineyard soils. The main aim of this study was to evaluate the effect of two liming materials, i.e. dolomitic lime and sugar foam, on a vineyard cultivated in an acid soil.Methods and results: The effects were studied in two soil layers (0-30 and 30-60 cm), as well as on leaf nutrient contents, grape yield, and must and wine quality properties, in a vineyard dedicated to Vitis vinifera L. cv. Mencía cultivation. The data management and analysis were carried out using ANOVA.Conclusion: Sugar foam was more efficient than dolomitic limestone as liming material since it induced the highest decrease in soil acidity properties at the same calcium carbonate equivalent dose. Effects of liming on leaf nutrient contents, grape yield, and must and wine quality properties were barely observed.Significance and impact of the study: Until recently, little was known about the effects of liming on both vine nutritional status and must/wine quality properties. Thus, this research fills an important knowledge gap.


2020 ◽  
Vol 4 (2) ◽  
pp. 392-400
Author(s):  
O. S. Balogun ◽  
M. A. Damisa ◽  
O. Yusuf ◽  
O. L. Balogun

The study was carried out to examine the effect of agricultural transformation on the beneficiary’s productivity and poverty of rice farmers in Kano State Nigeria. A multi-stage sampling method was employed to select 571 respondents for the study. Data were collected through structured questionnaires on respondent’s income, input and output quantities as well as their expenditures. Data were analysis using descriptive statistics, Foster-Greer-Thorbecke (FGT), Propensity score matching and LATE model. Results from the study shows that respondents productivity revealed a significant difference of about 127 kg/ha in rice productivity between participants and non-participants. Also, the LATE estimates revealed an average treatment effect ATE0 of about 222.98kg/ha. Furthermore, the project had a significant effect N11, 321.4 on the participant’s consumption expenditure than the non-participants N9980.60. Moreover, participants were, able to increase their household total expenditures by N34780 per annum. Fluctuations of input/output prices insect pests and inadequate extension visits were all the major constraints faced by the farmers. It was recommended that farmers’ information and sensitization system should be overhauled and improved. Also, attention should be given to well organize extension visits for the farmers from stake holders


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 895
Author(s):  
Jing Xu ◽  
Kaihui Zhang ◽  
Andrew G. S. Cuthbertson ◽  
Cailian Du ◽  
Shaukat Ali

Nanotechnology has clear potential in the development of innovative insecticidal products for the biorational management of major insect pests. Metal-based nanoparticles of different microbial pest control agents have been effective against several pests. Synthesis of Beauveria brongniartii based Fe0 nanoparticles (Fe0NPs) and their bio-efficacy against Spodoptera litura was observed during this study. Beauveria brongniartii conidia were coated with Fe0NPs and characterized by applying a selection of different analytical techniques. Ultraviolet (UV) spectroscopy showed the characteristic band of surface plasmon at 430 nm; Scanning electron microscopy (SEM) images showed spherical shaped nanoparticles with a size ranging between 0.41 to 0.80 µm; Energy-dispersive X-ray (EDX) spectral analysis revealed characteristic Fe peaks at 6.5 and 7.1 Kev; the X-ray diffractogram showed three strong peaks at 2θ values of 45.72°, 64.47°, and 84.05°. The bioassay studies demonstrated that mortality of 2nd instar S. litura larvae following Fe0NPs treatment increased with increasing concentrations of Fe0NPs at different time intervals. The median lethal concentration (LC50) values of Fe0NPs against S. litura after seven days of fungal treatment was 59 ppm, whereas median survival time (LT50) values for 200 and 500 ppm concentrations of Fe0NPs against S. litura seven days post-treatment were 5.1 and 2.29 days, respectively. Beauveria brongniartii-Fe0NPs caused significant reductions in feeding and growth parameters (relative growth rate, relative consumption rate, and efficiency of conversion of ingested food) of S. litura. Beauveria brongniartii Fe0NPs induced reduction in glutathione-S-transferase activities throughout the infection period whereas activities of antioxidant enzymes decreased during later periods of infection. These findings suggest that B. brongniartii Fe0NPs can potentially be used in biorational S. litura management programs.


Author(s):  
Jiahao Ling ◽  
Xiaoping Li ◽  
Guo Yang ◽  
Tongming Yin

AbstractPlagiodera versicolora Laicharting is a highly damaging leaf beetle foraging on willow leaves. In willow germplasm collections, observation has shown that Salix suchowensis Cheng was severely foraged by this leaf beetle while Salix triandra L. was damage free or only slightly damaged. Results of olfactometer bioassays show that the headspace volatiles from leaves of S. triandra significantly repelled adult beetles, suggesting that this species produces volatile repellents against P. versicolora. S. suchowensis had no effect on the beetles. Gas chromatography-mass spectrometry was carried out to profile the headspace volatile organic compounds and 23 compounds from leaves of the alternate species in significantly different concentrations were detected. The effects of 20 chemical analogs on host discrimination were examined. Olfactory response to these chemicals showed that o-cymene, a S. suchowensis specific constituent, significantly attracted adult P. versicolora. In contrast, cis-3-hexenyl acetate, a constituent concentrated more in S. triandra than in S. suchowensis, significantly repelled beetles. Mixing o-cymene and cis-3-hexenyl acetate in comparable concentrations as in the volatiles of S. suchowensis demonstrated that the latter could mask the attracting effect of the former, causing a neutral response by adult beetles to leaves of S. suchowensis against clean air. In addition, chemical analogs have the same effect as plants when resembling volatile organic compounds in real samples. Two volatile metabolites were detected triggering host discrimination by one of the most damaging insect pests to host and non-host willows. The two metabolites are of considerable potential for use as olfactory signs in managing the beetles.


Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Zienab Raeyat ◽  
Jabraiel Razmjou ◽  
Bahram Naseri ◽  
Asgar Ebadollahi ◽  
Patcharin Krutmuang

Due to the detrimental side-effects of synthetic pesticides, the use of nonchemical strategies in the management of insect pests is necessary. In the present study, the susceptibility of fourteen eggplant cultivars to green peach aphid (M. persicae) were investigated. According to preliminary screening tests, ‘Long-Green’, ‘Ravaya’ and ‘Red-Round’ as relatively resistant, and ‘White-Casper’ and ‘Pearl-Round’ as susceptible cultivars were recognized. In the antixenosis tests, the highest hosting preference was documented for ‘White-Casper’. Population growth parameters were used for evaluation of antibiosis. The highest and lowest developmental time (d) was observed on ‘Long-Green’ (4.33 d) and ‘White-Casper’ (3.26 d), respectively. The highest and lowest intrinsic rates of population increase (rm) were on ‘White-Casper’ (0.384 d−1) and ‘Long-Green’ (0.265 d−1), respectively. Significant differences were observed in the height and fresh and dry weight of infested and noninfected plants. Plant resistance index (PRI), as a simplified way to assess all resistance mechanisms, provides a particular value to determine the proper resistant cultivar. The greatest PRI value was observed on ‘Long-Green’. In general, the ‘Long-Green’ showed the least, and the ‘White-Casper’ displayed the most susceptibility among tested cultivars infested by M. persicae, which might be useful in integrated management of this pest.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 787
Author(s):  
Tshikala Eddie Lulamba ◽  
Ezekiel Green ◽  
Mahloro Hope Serepa-Dlamini

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.


1995 ◽  
Vol 46 (3) ◽  
pp. 583 ◽  
Author(s):  
RJQ Tarr

Growth rates of a number of Haliotis midae populations around the South African coast were studied by means of tagging. These populations ranged from the cool waters of the western coast to the more temperate environment of the eastern Cape. Standard von Bertalanffy growth curves were fitted and growth parameters derived. These ranged from 0.19 to 0.25 for K, the average rate at which L∞ is approached, and from 156 to 173 for L∞, the average theoretical maximum length. These indicate far higher growth rates than were previously published for this commercially fished species, and the reasons for this difference are discussed. The expectation that growth rates would be fastest in the warmer eastern Cape waters was not realized, there being no significant difference in growth between the Bird Island population on the eastern coast and the Robben Island population on the western coast. These new growth parameters indicate that H. midae in the commercial fishery grounds is attaining sexual maturity some four years earlier, and the minimum legal size some five years earlier, than previously considered. This has considerable significance for modelling studies presently underway. Movement of a small population of adult H. midae was studied over a three-year period, after which 47% of the original abalone were still present on the study site. Of these, 81.5% still occupied exactly the same position on the rocks. This indicates that H. midae that have located an optimum habitat, and that are not disturbed, tend not to move.


Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 665 ◽  
Author(s):  
Charalampos Filippou ◽  
Inmaculada Garrido-Jurado ◽  
Nicolai Meyling ◽  
Enrique Quesada-Moraga ◽  
Robert Coutts ◽  
...  

The use of mycoviruses to manipulate the virulence of entomopathogenic fungi employed as biocontrol agents may lead to the development of novel methods to control attacks by insect pests. Such approaches are urgently required, as existing agrochemicals are being withdrawn from the market due to environmental and health concerns. The aim of this work is to investigate the presence and diversity of mycoviruses in large panels of entomopathogenic fungi, mostly from Spain and Denmark. In total, 151 isolates belonging to the genera Beauveria, Metarhizium, Lecanicillium, Purpureocillium, Isaria, and Paecilomyces were screened for the presence of dsRNA elements and 12 Spanish B. bassiana isolates were found to harbor mycoviruses. All identified mycoviruses belong to three previously characterised species, the officially recognised Beauveria bassiana victorivirus 1 (BbVV-1) and the proposed Beauveria bassiana partitivirus 2 (BbPV-2) and Beauveria bassiana polymycovirus 1 (BbPmV-1); individual B. bassiana isolates may harbor up to three of these mycoviruses. Notably, these mycovirus species are under distinct selection pressures, while recombination of viral genomes increases population diversity. Phylogenetic analysis of the RNA-dependent RNA polymerase gene sequences revealed that the current population structure in Spain is potentially a result of both vertical and horizontal mycovirus transmission. Finally, pathogenicity experiments using the Mediterranean fruit fly Ceratitis capitata showed no direct correlation between the presence of any particular mycovirus and the virulence of the B. bassiana isolates, but illustrated potentially interesting isolates that exhibit relatively high virulence, which will be used in more detailed virulence experimentation in the future.


2006 ◽  
Vol 43 (4) ◽  
pp. 305-309
Author(s):  
Camila Carbone Prado ◽  
Roberto José Negrão Nogueira ◽  
Antônio de Azevedo Barros-Filho ◽  
Elizete Aparecida Lomazi da Costa-Pinto ◽  
Gabriel Hessel

BACKGROUD: Chronic liver diseases in childhood often cause undernutrition and growth failure. To our knowledge, growth parameters in infants with neonatal cholestasis are not available AIM: To evaluate the nutritional status and growth pattern in infants with intrahepatic cholestasis and extrahepatic cholestasis. PATIENTS AND METHODS: One hundred forty-four patients with neonatal cholestasis were followed up at the Pediatric Gastroenterology Service of the Teaching Hospital, State University of Campinas, Campinas, SP, Brazil, in a 23-year period, from 1980 to 2003. The records of these patients were reviewed and patients were classified into two groups, according to their anatomical diagnosis: patients with intrahepatic cholestasis - group 1, and patients with extrahepatic cholestasis - group 2. Records of weight and height measurements were collected at 4 age stages of growth, in the first year of life: 1) from the time of the first medical visit to the age of 4 months (T1); 2) from the 5th to the 7th month (T2); 3) from the 8th to the 10th month (T3); and 4) from the 11th to the 13th month (T4). The weight-by-age and height-by-age Z-scores were calculated for each patient at each stage. In order for the patient to be included in the study it was necessary to have the weight and/or height measurements at the 4 stages. Analyses of variance and Tukey's tests were used for statistical analysis. Repeated measurement analyses of variance of the weight-by-age Z-score were performed in a 60-patient sample, including 29 patients from group 1 and 31 patients from group 2. The height-by-age data of 33 patients were recorded, 15 from group 1 and 18 from group 2 RESULTS: The mean weight-by-age Z-scores of group 1 patients at the 4 age stages were: T1=-1.54; T2=-1.40; T3=-0.94; T4=-0.78. There was a significant difference between T2 X T3 and T1 X T4. The weight-by-age Z-scores for group 2 patients were :T1=-1.04; T2=-1.67; T3=-1.93 and T4=-1.77, with a significant difference between T1 X T2 and T1 X T4. The mean weight-by-age Z-scores also showed a significant difference between group 1 and group 2 at stages T3 and T4. The mean height-by-age Z-scores at the four stages in group 1 were: T1=-1.27; T2=-1.16; T3=-0.92 and T4=-0.22, with a significant difference between T3XT4 and T1XT4. The scores for group 2 patients were: T1=-0.93; T2=-1.89; T3=-2.26 and T4=-2.03, with a significant difference between T1XT2 and T1XT4. The mean height-by-age Z-scores also showed a significant difference between group 1 and group 2 at T3 and T4 CONCLUSION: The weight and height differences between the groups became significant from the 3rd measurement onward, with the most substantial deficit found in the extrahepatic group. In this group, there is evidence that the onset of weight and height deficit occurs between the first and second evaluation stages.


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