Subcuticular-Intracellular Hemibiotrophic and Intercellular Necrotrophic Development of Colletotrichum acutatum on Almond

The early infection and colonization processes of Colletotrichum acutatum on leaves and petals of two almond cultivars with different susceptibility to anthracnose (i.e., cvs. Carmel and Nonpareil) were examined using digital image analysis of light micrographs and histological techniques. Inoculated tissue surfaces were evaluated at selected times after inoculation and incubation at 20°C. Depth maps and line profiles of the digital image analysis allowed rapid depth quantification of fungal colonization in numerous tissue samples. The results showed that the early development of C. acutatum on petals was different from that on leaf tissue. On petals, conidia germinated more rapidly, germ tubes were longer, and fewer appressoria developed than on leaves. On both tissues, penetration by the pathogen occurred from appressoria and host colonization was first subcuticular and then intracellular. On petals, colonizing hyphae were first observed 24 h after inoculation and incubation at 20°C, whereas on leaves they were seen 48 to 72 h after inoculation. Intercellular hyphae were formed before host cells became necrotic and macroscopic lesions developed on petals ≥48 h and on leaves ≥96 h after inoculation. Histological studies complemented data obtained by digital image analysis and showed that the fungus produced infection vesicles and broad hyphae below the cuticle and in epidermal cells. In both tissues, during the first 24 to 48 h after penetration fungal colonization was biotrophic based on the presence of healthy host cells adjacent to fungal hyphae. Later, during intercellular growth, the host-pathogen interaction became necrotrophic with collapsed host cells. Quantitative differences in appressorium formation and host colonization were found between the two almond cultivars studied. Thus, on the less susceptible cv. Nonpareil fewer appressoria developed and host colonization was reduced compared with that on cv. Carmel.

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Assessment of Severity of Powdery Mildew Infection of Sweet Cherry Leaves by Digital Image Analysis

HortScience ◽

10.21273/hortsci.36.1.107 ◽

2001 ◽

Vol 36 (1) ◽

pp. 107-111 ◽

Cited By ~ 22

Author(s):

James W. Olmstead ◽

Gregory A. Lang ◽

Gary G. Grove

Keyword(s):

Image Analysis ◽

Powdery Mildew ◽

Digital Image ◽

Digital Image Analysis ◽

Sweet Cherry ◽

Prunus Avium ◽

Leaf Tissue ◽

Visual Assessment ◽

Accurate Method ◽

Leaf Disk

A personal computer-based method was compared with standard visual assessment for quantifying colonization of sweet cherry (Prunus avium L.) leaves by powdery mildew (PM) caused by Podosphaera clandestina (Wallr.:Fr.) Lev. Leaf disks from 14 cultivars were rated for PM severity (percentage of leaf area colonized) by three methods: 1) visual assessment; 2) digital image analysis; and 3) digital image analysis after painting PM colonies on the leaf disk. The third technique, in which PM colonies on each leaf disk were observed using a dissecting microscope and subsequently covered with white enamel paint, provided a standard for comparison of the first two methods. A digital image file for each leaf disk was created using a digital flatbed scanner. Image analysis was performed with a commercially available software package, which did not adequately detect slight differences in color between PM and sweet cherry leaf tissue. Consequently, two replicated experiments revealed a low correlation between PM image analysis and painted PM image analysis (r2 = 0.66 and 0.46, P ≤ 0.0001), whereas visual assessment was highly correlated with painted PM image analysis (r2 = 0.88 and 0.95, P ≤ 0.0001). Rank orders of the 14 cultivars differed significantly (P ≤ 0.05) when PM image analysis and painted PM image analysis were compared; however, rankings by visual assessment were not significantly different (P > 0.05) from those by painted PM image analysis. Thus, standard visual assessment is an accurate method for estimating disease severity in a leaf disk resistance assay for sweet cherry PM.

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The Histochemical Alterations of Mucin in Colorectal Carcinoma Quantified by Two Efficient Algorithms of Digital Image Analysis

International Journal of Molecular Sciences ◽

10.3390/ijms20184580 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4580 ◽

Cited By ~ 2

Author(s):

Kasprzak ◽

Seraszek-Jaros ◽

Jagielska ◽

Helak-Łapaj ◽

Siodła ◽

...

Keyword(s):

Image Analysis ◽

Digital Image ◽

Digital Image Analysis ◽

Periodic Acid ◽

Daily Practice ◽

Blue Staining ◽

Alcian Blue Staining ◽

Computer Assisted ◽

Periodic Acid Schiff ◽

Tissue Samples

The practical use of knowledge on the diagnostic-prognostic role of polysaccharide components of mucins in colorectal cancer (CRC) has been difficult, due to the number of histochemical (HC) reaction types, as well as lack of standard methods of computer-assisted analysis of tissue expression of these molecules. Using two algorithms of digital image analysis (by application of Image-Pro Premier and our originally designed program Filter HSV), we evaluated the expression of polysaccharides in tissue samples of CRC patients (n = 33), and fragments of normal colorectal tissue from the same patients (control) using periodic acid Schiff reaction (PAS) (neutral mucins) and alcian blue staining (AB) (acidic mucins). Our results indicate lower expression of the PAS+ and AB+ mucins in CRC, as compared to the control samples. The higher expression of PAS+ polysaccharides was detected in flat tumors than in protruded CRC, while higher AB+ mucins expression was a feature of mucinous CRC subtypes. Positive correlation between mutual PAS+ and AB+ expression, as well as correlations with glucose concentration (PAS+ mucins), and hemoglobin level (AB+ mucins) were observed exclusively in unchanged colorectal samples (control). Both algorithms of digital image analysis (smart segmentation and Filter HSV) work properly and can be used interchangeably in daily practice of pathologists, as useful tools of quantitative evaluation of HC reaction in both normal and cancerous tissues.

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The Potential of Digital Image Analysis to Determine Tumor Cell Content in Biobanked Formalin-Fixed, Paraffin-Embedded Tissue Samples

Biopreservation and Biobanking ◽

10.1089/bio.2020.0105 ◽

2021 ◽

Author(s):

Christine Greene ◽

Edwina O'Doherty ◽

Fatima Abdullahi Sidi ◽

Victoria Bingham ◽

Natalie C. Fisher ◽

...

Keyword(s):

Image Analysis ◽

Tumor Cell ◽

Digital Image ◽

Digital Image Analysis ◽

Cell Content ◽

Tissue Samples ◽

Formalin Fixed Paraffin ◽

Formalin Fixed Paraffin Embedded ◽

Formalin Fixed

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Digital Image Analysis of Internal Light Spots of Appressoria of Colletotrichum acutatum

Phytopathology ◽

10.1094/phyto.2003.93.8.923 ◽

2003 ◽

Vol 93 (8) ◽

pp. 923-930 ◽

Cited By ~ 24

Author(s):

J. Diéguez-Uribeondo ◽

H. Förster ◽

J. E. Adaskaveg

Keyword(s):

Image Analysis ◽

Digital Image ◽

Digital Image Analysis ◽

Colletotrichum Acutatum ◽

Depth Of Field ◽

Scanning Electron Micrographs ◽

Image Analysis Technique ◽

Analysis Technique ◽

Initial Penetration ◽

Scanning Electron

The initial penetration process of appressoria of Colletotrichum acutatum on almond leaves was studied using digital image analysis of light micrographs and scanning electron microscopy. For image analysis, a series of sequential, partially focused digital micrographs of appressoria was analyzed to generate a single, completely focused montage image with a continuous in-focus depth of field. In studies on the development of the internal light spot (ILS), we observed that 50.4% of the appressoria formed an ILS after leaves were inoculated and incubated for 12 h at 20°C, and that this increased to 95.8% after 24 h. Comparative image analyses of appressoria with and without ILSs using depth relief mapping and line profile software options showed that the ILS had a depth relief that was below that of the leaf surface. Depth relief analysis in the ILS region during incubation revealed an increase in depth in this area of up to 1.8 μm in some of the appressoria. A comparative morphological study of the ILS in montage images and the penetration pore of appressoria in scanning electron micrographs showed similar shapes and dimensions of the two structures in the appressorium. Light micrographs of histological sections confirmed fungal penetration and internal vesicle formation in almond leaves within 36 h after inoculation and incubation at 20°C. This study represents the first direct evidence that the ILS in appressoria corresponds to the penetration pore and the developing penetration peg using a rapid, digital image analysis technique.

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