Hyphal interactions between a mycoparasite, Pythium nunn, and several soil fungi

1984 ◽  
Vol 30 (12) ◽  
pp. 1482-1487 ◽  
Author(s):  
R. Lifshitz ◽  
M. Dupler ◽  
Y. Elad ◽  
R. Baker
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Host Range ◽  
Phase Contrast ◽  
Soil Fungi ◽  
Limited Host Range ◽  
Pythium Nunn ◽  
Scanning Electron

The modes of hyphal interaction between a mycoparasite, Pythium nunn, and several soil fungi were studied by both phase-contrast and scanning-electron microscopy. In the zone of interaction, Pyth. nunn massively coiled around and subsequently lysed hyphae of Pyth. ultimum and Pyth. vexans. In contrast, Pyth. nunn penetrated and eventually parasitized hyphae of Rhizoctonia solani, Pyth. aphanidermatum, Phytophthora parasitica, and Phyto. cinnamomi by forming appressoriumlike structures. However, Pyth. nunn was not mycoparasitic against Fusarium oxysporum f.sp. cucumerinum or Trichoderma koningnii and was destroyed by T. harzianum and T. viride. These observations demonstrated that Pyth. nunn was a necrotrophic mycoparasite, with a limited host range and differential modes of action among suscepts.

Coelomomyces canadense stat. et comb. nov. (Blastocladiales: Coelomomycetaceae) from Psectrocladius sp. G (Diptera: Chironomidae)

1978 ◽  
Vol 56 (18) ◽  
pp. 2303-2306 ◽  
Author(s):  
Richard A. Nolan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Contrast ◽  
Field Phase ◽  
Species Status ◽  
Bright Field ◽  
Latin Diagnosis ◽  
Taxonomic Criterion ◽  
Sporangial Wall ◽  
Scanning Electron

Resistant sporangia of Coelomomyces chironomi var. canadense Weiser and McCauley were examined by bright-field, phase-contrast, and scanning electron microscopy (SEM). The use of SEM facilitated the observation of previously undescribed complex furrows in the sporangial wall. The taxonomic criterion for varietal status is discussed, and the variety is elevated to species status. Coelomomyces canadense (Weiser and McCauley) Nolan stat. et comb. nov. is described with an emended Latin diagnosis.

Contribution à l'étude du Bayoud, fosariose du palmier-dattier. I. Étude du cultivar sensible Deglet-Nour

1990 ◽  
Vol 68 (10) ◽  
pp. 2054-2058 ◽  
Author(s):  
Béatrice Mathéron ◽  
Abdellatif Benbadis
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fusarium Oxysporum ◽  
Spore Germination ◽  
Date Palm ◽  
Wilt Disease ◽  
Root Epidermis ◽  
Bordered Pits ◽  
Early Reaction ◽  
Scanning Electron

Date palm seedlings were inoculated at the two-leaf stage with Fusarium oxysporum f. sp. albedinis, the causal agent of Bayoud. Following spore germination, hyphae bore a bole through the walls of the root epidermis and penetrated into the cortical parenchyma. The fungus then grows inter- or intra-cellularly towards the central cylinder and enters the xylem vessels. There, it continues to grow towards the leaves. The progression from vessel to vessel is achieved through bordered pits. The cultivar Deglet-Nour, known for its susceptibility to this wilt disease, exhibited no early reaction to the presence of the parasite in its tissues. Key words: date palm, Fusarium oxysporum f. sp. albedinis, scanning electron microscopy.

scholarly journals Scanning electron microscopy and enzymatic analysis in Agave americana during Fusarium oxysporum infection

2020 ◽  
Vol 38 (3) ◽  
Author(s):  
Sheila Jazmín Reyes-Zambrano ◽  
Carlos Alberto Lecona-Guzmán ◽  
Federico Antonio Gutiérrez-Miceli ◽  
Nancy Santana-Buzzy ◽  
Ignacio Islas-Flores ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fusarium Oxysporum ◽  
Enzymatic Analysis ◽  
Agave Americana ◽  
Scanning Electron

La quitinasa y <em>B</em>-1,3-glucanasa desempeñan una función importante en la reacción de defensa contra patógenos fúngicos. En <em>Agave americana</em> existe poca información sobre el comportamiento de estas proteínas en respuesta a la infección de <em>Fusarium oxysporum</em>. En este estudio, se realizó un análisis de microscopía electrónica de barrido (MEB) en raíces de A. americana infectadas con <em>F. oxysporum</em> y se evaluó la actividad de quitinasa y <em>B</em>-1,3-glucanasa en raíces de <em>A. americana</em> a 0, 7, 15 y 30 días después de inoculación con<em> F. oxysporum</em>. MEB reveló que 15 días después de la inoculación (DDI) son suficientes para que el hongo infecte las raíces de<em> A. americana</em>. La actividad de quitinasa en plantas infectadas incrementó significativamente a los 15 DDI con respecto a las plantas no infectadas, mientras que la actividad de <em>B</em>-1,3 glucanasa no presentó diferencia estadística significativa con plantas testigo. Los resultados sugieren que, en respuesta a la infección por <em>F. oxysporum</em>, <em>A. americana</em> activa proteínas PRs de tipo quitinasas.

Brittle fracture of epidermal cells by liquid shear

1976 ◽  
Vol 20 (3) ◽  
pp. 699-705
Author(s):  
G.M. Gray ◽  
H.J. Yardley
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Contrast ◽  
Epidermal Cells ◽  
Transmission Electron ◽  
The Press ◽  
Contrast Microscopy ◽  
Cell Fragments ◽  
Scanning Electron ◽  
Liquid Shear

A suspension of epidermal cells obtained from pig tail skin by trypsinization was subjected to high liquid-shear forces in a French press. The material issuing from the press was examined by phase-contrast microscopy, transmission electron microscopy and scanning electron microscopy. The cytoskeleton of tonofibrils retained the shape of cell fragments, and subcellular organelles remained enmeshed in the network of tonofibrils. Examination of some cell fragments by scanning electron microscopy revealed the internal organization of the tonofibrils. The relevance of these findings to the problem of isolating subcellular fractions from epidermis is discussed.

Phase contrast and scanning electron microscopy of a soil amoeba, Hartmannella glebae

1986 ◽  
Vol 44 ◽  
pp. 300-301
Author(s):  
J. Upadhyay ◽  
M. J. Schurr ◽  
R. J. Lesseps
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Current Literature ◽  
Phase Contrast ◽  
The Other ◽  
Other Hand ◽  
As Species ◽  
Soil Amoeba ◽  
Scanning Electron

The genera Hartmannella and Acanthamoeba have been controversial. Some species of Acanthamoeba have been cited as species of Acanthamoeba, Mayorella, or Amoeba and a confusing lack of agreement persists in current literature. The genus Hartmannella was redefined by Page in 1967 to include those species which assumed a simple monopodial, limax-like form during locomotion and, where known, the cysts were smooth-walled and rounded with no opercula. The genus Acanthamoeba, on the other hand, possessed tapering, hyaline pseudopods (acanthopodia) and a cyst made up of an ectocyst and a polyhedral or stellate endocyst, with excystment by removal of opercula.

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