How can we determine which pathogen (bacteria, fungi, virus) is responsible for a given plant disease from a phenotypic observation (for example: spots, smudges on leaves) ??
All instrumental methods can be applied for the pathogen identification (microscopic analysis, wet chamber, pure culture isolation, artificial inoculation tests, biochemical tests like LOPAT for Pseudomonas, ELISA, FAME, PCR, LAMP, DNA sequencing, MALDI), but they are quite far from the simple phenotypic observation.
Mohammad,
The task of the disease identification by image analysis can be done with one of many expert systems based on PC or mobile phone. If you look for way to do it by visual observation, I would say that you need many years of work in field plant pathology.
Regards
Alex
https://plantvillage.psu.edu/blog
https://www.ijcsmc.com/docs/papers/January2016/V5I1201618.pdf
Chapter Intelligent Pattern Recognition System with Application to C...
Article Automated identification of sugar beet diseases using smartphones
Chapter Cell Phone Image-Based Plant Disease Classification
https://www.colwiz.com/public/publication/f2088b346834d71/cell_phone_image_based_plant_disease_classification
https://ijarcce.com/upload/2016/march-16/IJARCCE%2094.pdf
http://www.euronews.com/2017/01/04/the-plant-doctor-app-helping-to-identify-plant-disease
Thank you Mr. Ignatov for your answer and the valuable links below.
I think that the use of selective antibiotics and 16S sequencing may be useful. Right?
All instrumental methods can be applied for the pathogen identification (microscopic analysis, wet chamber, pure culture isolation, artificial inoculation tests, biochemical tests like LOPAT for Pseudomonas, ELISA, FAME, PCR, LAMP, DNA sequencing, MALDI), but they are quite far from the simple phenotypic observation.
I agreed Dr. Alex. For identification of plant pathogen, we need to follow Koch’s postulates by artificial inoculation to confirm the suspected pathogen is present or not. http://www.life.umd.edu/classroom/bsci424/BSCI223WebSiteFiles/KochsPostulates.htm
After confirmation, biochemical or molecular studies were performed for detailed studies on species level.
External symptoms are generally related with various pattern of pigment loss, stunting and deformity of plant or plant part, sometimes association of spores, conidia, fruiting bodies in case of fungi , eggs or larvae in case of insect or nematode. For confirmation microscopic observation may help.
Mohammad,
16S rRNA sequencing is good for new bacteria identification, and antibiotic resistance (and other biochemical) tests are good for evaluation of bacterial plant pathogens diversity. Detection and diagnostics of the most expected pathogens can be done in rare case by phenotype (I agree with Prof. Rekha Arya - some diseases have distinct traits and microscopic observation may help a lot for fungi or nematodes), but, it is better to use PCR or IFA (ELISA) for virus or bacteria identification. Virus diseases are especially harmful in mixture of two or more species (like PVY+PVX or PVM, TuMV+CaMV, etc.), and bacteria have rapid succession of major components - specific pathogens are succeeded by soft rot pathogens or by semi-pathogenic bacteria.
Alex
Dear Mohammad,
Every pathogen has its own specific symptoms. e.g. some plant viruses produced typical symptoms (like begomovirus produced leaf curling, yellow veins, mosaic yellow pattern, leaf deformation, enation, vein thickening, vein swelling) so this appearance we assumed the disease may be caused by begomovirus. Further confirmation is also done by using diagnostic tools like PCR, Blots, ELISA etc.
Similar is the case of bacteria and fungi.
Carry a study on the physical manifestation of the disease pathogen*bacterial*fungi*virus* and *nematode in relation to the distinct characteristics and later *Koch's Postulate* for disease diagnostic. Agnes Wakesho Mwang'ombe
Dear Mohammad,
I agree with all valuable responder opinion. However, it is difficult to explain your question with a few words here. I suggest you to have a look plant pathologists’ constitution book (Plant Pathology edited by Agrios).
Dear for this you shall go for a plant pathologist, only a pathologist can be helpful and can make sure about any disease and their related studies.
- Badges
- Science topic
- Similar topics
- Biological Science
- Microbiology
- Microorganisms
- Bacteria