scholarly journals Abiotic and Biotic Factors Affecting Resting Spore Formation in the Mite PathogenNeozygites floridana

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Vanessa da Silveira Duarte ◽  
Karin Westrum ◽  
Ana Elizabete Lopes Ribeiro ◽  
Manoel Guedes Corrêa Gondim Junior ◽  
Ingeborg Klingen ◽  
...  
Keyword(s):  
Pathogenic Fungus ◽  
Field Studies ◽  
Spore Formation ◽  
Biotic Factors ◽  
Tetranychus Evansi ◽  
Tropical Regions ◽  
Factors Affecting ◽  
Resting Spore ◽  
Resting Spores ◽  
Abiotic And Biotic Factors

Neozygites floridanais an obligate mite pathogenic fungus in the Entomophthoromycota. It has been suggested that resting spores of this fungus are produced as a strategy to survive adverse conditions. In the present study, possible mechanisms involved in the regulation of resting spore formation were investigated in the hostsTetranychus urticaeandTetranychus evansi. Abiotic and biotic factors mimicking conditions that we, based on earlier field studies, thought might induce resting spores in temperate and tropical regions were tested with isolates from Norway and Brazil. A total of 42 combinations of conditions were tested, but only one induced the formation of a high number of resting spores in only one isolate. The Brazilian isolate ESALQ1420 produced a large number of resting spores (51.5%) inT. urticaeat a temperature of 11°C, photoperiod of 10L:14D, and light intensity of 42–46 (μmol m−2 s−1) on nonsenescent plants (nondiapausing females). Resting spores of the BrazilianN. floridanaisolate ESALQ1421 were found at very low levels (up to 1.0%). Small percentages ofT. urticaewith resting spores (0–5.0%) were found for the Norwegian isolate NCRI271/04 under the conditions tested. The percentages of resting spores found for the Norwegian isolate in our laboratory studies are similar to the prevalence reported in earlier field studies.

Factors affecting the production of resting spores by Zoophthora radicans in the spotted alfalfa aphid, Therioaphis trifolii f. maculata

1989 ◽  
Vol 67 (3) ◽  
pp. 848-855 ◽  
Author(s):  
Travis R. Glare ◽  
Richard J. Milner ◽  
Graham A. Chilvers
Keyword(s):  
Indirect Evidence ◽  
Spore Production ◽  
Factors Affecting ◽  
Resting Spore ◽  
Solid Media ◽  
Number Of Factors ◽  
Resting Spores ◽  
Saturated Atmosphere ◽  
Zoophthora Radicans ◽  
Genetic Combination

Resting spore production by Zoophthora radicans (Brefeld) Batko in infected cadavers of the spotted alfalfa aphid, Therioaphis trifolii (Monell) f. maculata, varied according to a number of factors. For four isolates of the fungus tested, the proportion of cadavers containing resting spores was consistently greater at 10 °C than at higher temperatures. At 20 °C, a saturated atmosphere (100% RH) favoured resting spore production, and the proportion of infected cadavers that contained resting spores was nearly twice the amount of that at 95% RH. Individual isolates of the fungus were found to differ in their ability to form resting spores in infected cadavers; some formed resting spores in few or no cadavers, whereas others formed resting spores in many, under similar conditions. The ability to produce resting spores sometimes varied following serial culturing on solid media. Interestingly, resting spore production was found to correlate with inoculum density. Also, inoculation of aphids with two fungal isolates resulted in a marked increase in resting spore production compared with that of either isolate alone. It is presumed that some form of genetic combination is involved. Indirect evidence suggests that this is more likely to be cytoplasmic than nuclear in origin.

Abiotic and biotic factors affecting crop seed germination and seedling emergence: a conceptual framework

2018 ◽  
Vol 432 (1-2) ◽  
pp. 1-28 ◽  
Author(s):  
Jay Ram Lamichhane ◽  
Philippe Debaeke ◽  
Christian Steinberg ◽  
Ming Pei You ◽  
Martin J. Barbetti ◽  
...  
Keyword(s):  
Seed Germination ◽  
Conceptual Framework ◽  
Seedling Emergence ◽  
Biotic Factors ◽  
Factors Affecting ◽  
Abiotic And Biotic Factors ◽  
Crop Seed

Formation and germination of resting spores from different strains from the Entomophthora muscae complex produced in Musca domestica

2001 ◽  
Vol 79 (9) ◽  
pp. 1076-1082 ◽  
Author(s):  
Lene Thomsen ◽  
José Bresciani ◽  
Jørgen Eilenberg
Keyword(s):  
Musca Domestica ◽  
House Fly ◽  
Spore Production ◽  
Spore Formation ◽  
Entomophthora Muscae ◽  
Resting Spore ◽  
Resting Spores ◽  
Group B ◽  
Different Strains

Three species within the Entomophthora muscae (Cohn) Fresenius complex (Entomophthora schizophorae Keller & Wilding, E. muscae s.str., and E. muscae "group B") were investigated for resting spore formation in vivo in the house fly (Musca domestica L.). Resting spores of E. muscae group B were experimentally induced from August to the beginning of February, while no resting spores were ever observed in E. schizophorae infected M. domestica or in flies infected by E. muscae s.str. originating from M. domestica. When newly dead fly cadavers containing E. muscae group B resting spores were kept moist, cystidia emerged from the abdomen; this is the first report of cystidia in the genus Entomophthora. Resting spore production was significantly affected by both temperature and E. muscae group B strain. More infected flies formed resting spores when kept 1 week at 10°C compared with constant exposure at 22°C, but the tendency of the different E. muscae group B strains to form resting spores persisted with shifting temperatures. After 4 months of incubation under natural winter conditions in Denmark, E. muscae group B resting spores germinated on water agar at 20°C with a 16 h light : 8 h dark photoperiod within 1 week, but no germ conidia were observed.Key words: Entomophthorales, Entomophthora muscae complex, Diptera, Musca domestica, resting spore formation, resting spore germination.

Abiotic and Biotic Factors Affecting the Ingestion Rates of Mixotrophic Nanoflagellates (Haptophyta)

2018 ◽  
Vol 77 (3) ◽  
pp. 607-615 ◽  
Author(s):  
Ya-Fan Chan ◽  
Kuo-Ping Chiang ◽  
Yun Ku ◽  
Gwo-Ching Gong
Keyword(s):  
Biotic Factors ◽  
Ingestion Rates ◽  
Factors Affecting ◽  
Abiotic And Biotic Factors

scholarly journals Assembly of Optimum Habitats for Asian Houbara Bustard (Chlamydotis macqueenii) in the Arabian Peninsula: The Vegetation Aspects

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Naseraldeen Baqer Asadalla ◽  
Mohammad Sulaiman Abido ◽  
Asma Abahussain ◽  
Mohamed Shobrak
Keyword(s):  
Arabian Peninsula ◽  
Species Abundance ◽  
Acacia Tortilis ◽  
Biotic Factors ◽  
Factors Affecting ◽  
Houbara Bustard ◽  
Abiotic And Biotic Factors ◽  
Study Sites ◽  
And Behavior ◽  
Line Intercept

This research was conducted in four sites at Mahazat as-Sayd reserve in Saudi Arabia to determine the optimum habitats’ constituents for Asian houbara bustard Chlamydotis macqueenii via assessing abiotic and biotic factors with special reference to vegetation aspects. Vegetative parameters were quantified using combinations of distance and line intercept methods. Acquired data were analyzed using cluster analysis and analysis of variance tests. Results indicated that three of the four plant communities of the study sites were dominated by Acacia tortilis with underground cover composed of lesser species. On the other hand, White Jabal was dominated by scrubs composed mainly of Fagonia indica with sparse Acacia trees. Rumrumiyya site recorded the highest species abundance and vegetative coverage (133%) among the sites. It is concluded that Black Jabal and White Jabal sites are used as nesting and foraging habitats for houbaras, whereas Jabal Khurse is specifically a males’ display site. Nevertheless, Rumrumiyya site was used for foraging and shelter. The study confirmed that density and vegetation cover are of prime importance for houbara site selection. However, other factors affecting feeding and behavior of the species must be considered in further studies.

scholarly journals Abiotic and biotic factors affecting the replication and pathogenicity of bee viruses

2016 ◽  
Vol 16 ◽  
pp. 14-21 ◽  
Author(s):  
Alexander J McMenamin ◽  
Laura M Brutscher ◽  
William Glenny ◽  
Michelle L Flenniken
Keyword(s):  
Biotic Factors ◽  
Factors Affecting ◽  
Abiotic And Biotic Factors ◽  
Bee Viruses
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