Questions related to Fungal Plant Pathology
I was wondering for how much time does a mycelium freshly isolated from plant tissue continue to be "similar to what it used to be" in nature. I can see that morphological changes frequently occur when transferring from plate to plate so in short, my question is: can I keep using a mycelium for a long time, making sure it still is the same? Should I re-isolate it from time to time? And, are there some techniques to prevent changes to happen?
There are many Alternaria pathogens that produce host-specific toxins. Alternaria host-specific toxins are classified in three groups in terms of the primary site action. First group of toxins have in common an epoxy-decatrienoic acid structure and exert their primary effect on the plasma membrane of susceptible cells. The second group is represented by ACR(L)-toxin, which induces changes in mitochondria, including swelling, vesiculation of cristae, decrease in the electron density of the matrix, increase in the rate of NADH oxidation, and inhibition of malate oxidation. The third group consists of AM-toxin, which appears to exert an early effect on both chloroplasts and plasma membranes.
Ames and bacterial assays has demonstrated that Altertoxins I, II, III, toxins AOH and AME were mutagenic. A.N. Samokhvalov ( «A method for producing mutant strains of plant pathogen X. campesrtis». Invention certificate No 1473360 of 15.12.1988 (USSR) has found that Alternaria brassicola caused similar mutation in different strains of X. campestris affected xanthomonadin synthesis and virulence of the bacteria.
Is there any information about specific interaction between Alternaria toxins and bacterial/chloroplast or mitochondrial DNA?
I am currently trying to get the Ceratocystis sp. using carrot baiting, there is present of fruiting body on the carrot but after I try to transfer the spore to the MEA, it failed because instead of Cerato there is bacteria growth. I had tried many times and I also tried to add penicillin in my MEA but it seems to have failed again. So, what is the technique for making sure that the spores is successfully transferred to MEA ?
I am looking for few common tobacco pathogens as well as other general plant fungal pathogens. If anyone will be willing to provide it then please contact me.
I'm still relatively new to genetic diversity analysis of plant pathogens. I'd like to ask for suggestions on how to produce a dendrogram consisting of a combination of several genetic markers using the NTSYS software.
I'm using SSR and ISSR markers to analyse the diversity of various isolates of Fusarium wilt pathogen. I'm confident of generating a data matrix using a single genetic marker (using binary codes) and then producing a dendrogram. However, I'm not entirely sure how the data matrix would look like when more than one genetic markers are used.
May I ask for your suggestions on how a data matrix consisting of more than one genetic markers would look like?
Also, is it necessary to test the combinability of data sets from different genetic markers using partition homogeneity test using PAUP software? Does anyone have any experience in handling such test using this software?
Thank you in advance.
When I was studying the feeding regime of the collembolan Pseudosinella alba, I reared it on a variety of fungal strains I had previously isolated from a black rendzina soil. This species exhibited clear preferences for some strains but was able to feed and reproduce on the majority of them, including the well-known pathogenic fungi Verticillium dahliae. The paper (in French) is here:
Pseudosinella alba lives in litter and feeds exclusively (and abundantly) on micro-fungi, both mycelia and spores, the germination of which becomes negligible once gut transit is completed and faeces are deposited. This property, scarce in Collembola (known for their opportunist feeding regime), is shared by other members of the genera Pseudosinella and Willemia. In this article I suggested that such species could be used for preventing pathogenic fungi to invade greenhouses and hydroponics, where pesticides are still currently used for the protection of cultures. Several attempts have been made by various authors to use springtails for the biological control of pathogenic fungi, but to my knowledge they are still not employed at this usage. However, these animals can be easily grown in boxes filled with plaster of Paris and fed with baker’s yeast, where their populations can reach very high densities providing they are fed ad libitum, as this is currently achieved in academic laboratories.
Catch as catch can…
I'm firstly interested in identifying Alternaria cultures to species level. After this, I will have a look at a specific pathotype. In this regard, would it be sufficient to use the ITS region for the initial identification to species level? I'll be happy if it can just tell me if a specific culture is Alternaria alternate or not. I appreciate your time.
I have isolated about 20 different kinds of Fungals from the fruit peel and now I would like to measure the spore concentration,
1- How can prepare the spore suspension solution for spore counting, as not sure which kind of fungi?
Many efforts have been done by the researchers to culture the fungus extracted from Taxus plants in different mediums but the success rate was less. Hence, the Taxus plants remains the only source for paclitaxel extracts which is important for preparation of Taxol used in diagnosing cancer patients.
Macrophomina phaseolina is a fungal pathogen with a host range of more than 500 plant families; inciting a stem cancer disease in many crops that is often referred to as charcoal rot, due to the charcoal type coloration imparted to the colonized plant tissues.
How effective is biological control among other management strategies for Macrophomina??
What are the black structures that appear on Botrytis cinerea mycellium after two weeks of in vitro culture??
I tried to observe them under binocular microscope and I think that they are fruiting bodies but I am not sure.
Can anyone cofirm this ??
I have tried aniline blue and cotton blue staining for root sections. They're not effective, in this case.
During the field harvest, I've managed to collect infected oak leaves with fungal hyphae, without any visual cues to identify the fungal species. I'm worried that I might confuse other species with actual pathogen if isolation failed.
Is there any clever way to boost the probability to isolate this unknown fungus solely? (weather condition were rainy / humid / 20'C to 30'C recently)
Hello, I want to preserve wheat blast fungus in glycerol for long term storage. However, I do not know the procedure for this particular fungus. What should be the concentration of glycerol? Do I need to make conidial suspension and then store it? or What is the whole procedure? please give me some suggestions.
I am interested to study the genetic diversity of a plant fungal pathogen. I have gathered potential genetic markers (around 30 sets) from journals to investigate their % polymorphism before selecting the suitable ones for further analysis. I have a total of 50 isolates of fungal pathogen. Do I have to screen 50 isolates at one time using one set of genetic marker?
In other words, can I just use 10 representative isolates, instead of 50 isolates, to screen for suitable genetic markers with high % of polymorphism? How many bands is needed to produce reliable genetic diversity results?
Thank you in advance.
I am interested in the life cycle of the dinoderus minutus as it consumes cut bamboo. It's digestion is dependent on symbiotic fungus.
I notice the bugs seem to have specific preferences for which bamboo it will infest first.
Are there known resources about what kinds of fungus are naturally included in bamboo? Are the on the external surface of the bamboo, or are they already incorporated into the bamboo wood?
Olive (Olea europaea L.) is one of the most important crops in the Mediterranean countries. Olive leaves, available throughout the year, are one of the byproducts of olive farming; they accumulate during the pruning of the olive trees and can be found in large amounts in olive oil industries after being separated from fruits before processing (about 10% of the weight of olives). Several reports have shown that olive leaves have antioxidant activity and anti-fungal properties, So, can be used dry leaves powder as protectants against phytopathogenic.
My lab is drafting a field trial in mildew resistance. Can someone suggest a good metered dose sprayer that would allow uniform area and fungal spore count onto a leaf surface?
We have considered a paint sprayer, but the lack of a 1-pump spray lead to variation in the amount of spores sprayed between people.
Additionally, nebulizers do not allow particle sizes between 15-30 microns, and are thus too small.
We have considered a nasal sprayer, but that shoots more of a spray over a uniform mist.
I cannot find any purchasable and empty metered dose inhalers that could be used for this online.
Thanks so much and I appreciate any help!
I am trying to extract DNA from Alternaria spores. They prove to be very tough to open. Does anyone have a lab protocol they are using to obtain a high yield of Alternaria spore DNA? Currently, I am using the E.Z.N.A. Universal Pathogen Kit and bead milling with a range of bead sizes from 0.1-0.5 mm. I am thinking of trying a pre-DNA extraction step of incubating with lyticase overnight at 30C, or trying a freeze thaw step with LN2.
Any help would be much appreciated!
I am currently establishing protocols for identification of plant pathogenic species by PCR. I tried primer pair BC108/BC563 published in 2006 by Rigottii and collegues, but it does not work with me (while I get excellent amplification with ITS1/ITS4 primer pair). Any suggestions or any experiences with BC108/BC563 ?
I’ve tried to isolating Phytophthora of avocado soil or any Solanaceae soil with different media culture like V8 or Carrot media, or even potato media and ornamental leaves tramp but not success yet, ¿does anybody know the best way to isolate this oomycete from soil?
I am working with pathogenic oomycetes in grasses which are asymptomatic and rarely produce sporangia growing out from the host tissue. The grass samples were fixed in 5% Glutaraldehyde in PBS (pH 7.5) and thus difficult to proceed with oomycete-specific probes for FISH (GA creates a very strong fluorescent background that even my negative controls reacts with the different filters). Apparently, I tried using multiple fluorescent stains and combinations (Aniline Blue, Trypan Blue, and Uvitex2b) although these stains also binds to chitin. The problem is the host plant may have both fungal and oomycete pathogens together. Likewise, it is already sure that my target parasite is present since specific primers were designed (sequences obtained were 99-100% identical and forms a clade with the same species with >95% support by RaxML) and the samples for microscopy where derived from the same batch. I had also considered morphological aspects like the presence and absence of septation, but reports of septation in the hyphae of oomycetes had been widely observed in different genera (Plasmopara, Peronospora, etc). Trying chitin degradation had been an option too, but the procedure is too tedious, likewise the chances of degrading cellulose and glucans of oomycete cell walls are highly possible. Considering my little amount of samples, this risk is also quite the least option for me. Sorry for the long detail, I hope someone can offer some suggestions. Thanks!
I need about 2000-5000 R. solani sclerotia for my experiments. I usually grew R. solani in Petri plates but I just get 10-12 sclerotia. It has wasted my time. I need a substrate on which I cultivate R. solani so that It may produce a lot of sclerotia for my experiments. Looking forward for your suggestions.
pathogenicity test needs seed clear from pathogen ; but they are mostly not available, so we some times use dusting seeds.
Plant apoplast contains various antimicrobial peptides e.g., defensins. As part of their antifungal mode of action, these defensins (not all defensins) are known to interact specifically with membrane-resident bioactive phospholipids, such as PA, PI(4,5)P2 with high affinity. We know that these pathogens have different life style. Very importantly, when biotrophic pathogens thrive in the apoplst, they encounter various antifungal proteins and fungus needs to protect itself from these proteins which subsequently determine the outcome. However, necrotrophic pathogens produce different cell wall-degrading enzymes (CWDEs) and toxins to kill the host plant cell. When necrotrophic pathogens damage the cell wall and plasma membrane, the antimicrobial peptides (e.g., defensins) which are present in the apoplast, may encounter plant membrane-resident bioactive phospholipids. Do you think these defensins highly interact with plant phospholipids (instead of fungal membrane-resident bioactive phospholipids) and indirectly regulate its own plant lipid metabolism? If so, why does it prefer binding to its own phospholipids? Does this non-specific interaction leads to toxicity to the plant cells? What about binding to fungal membrane-resident bioactive phospholipids? Does defensin loses it ability to bind to fungal phospholipids, subsequently paving the way to infect the plant? How do transgenic (and also non-transgenic) plants over expressing phospholipid-binding proteins (e.g., defensins) control itself of these non-specific interactions? Do you think the change in the environment (e.g., pH) can limit these non-specific interactions in both non-transgenic and overexpressing plants ?
I place some of R. solani cultured Petriplates under fluorescent tubes and some of the Petri dishes in complete dark. The results were surprising, the color of R. solani under flouresent tubes as whitish while the color of R. solani which were placed in dark as completely dark. What is the reason?
Hello everyone, I am interested in infecting eggplants with microsclerotia of V. dahliae and I need a clear method on how to do it. Thank you!
What can be precise phenotypic parameters of partial resistance to stripe rust rust pathogen in wheat at seedling stage. There are numerous such latency period 1, latency peiord 50, infection type, uredinium size , infection frequency etc. Suggest two or three?
Trichoderma are promising biological bio-protectants agent against plant pathogenic fungi. Producing large number of spores and unaffected to environmental variabilities and and have a long shelf life are definitely required.
(a) Fungal spp. - Hypholoma spp., Phlebiopsis gigantea, Armillaria ostoyae, Heterobasidion irregulare. (b) observing interaction pairings
I need the detail list of techniques used in the screening of fusarium wilt in Musk melon and even the scale required for evaluation.
In my project which deals with how certain fungicides affect certain fungi, one of the aspects of data collection is daily spore count after the fungi has been met with fungicides and are being studied.
I am working with wild relatives of rice.
I have been facing an issue with the germination as the seeds are highly contaminated.
I tried to use ethanol 70% 2 minutes, bleach 4% for 30 minutes, mercury chloride 0.1% for 3 minutes.
Still, the blueish fungi appear on the seeds (in the petri dish).
Any recommendations? maybe try to use vaccum infiltration in order to help penetrate the seed's wax? Have anybody done it before?
Many thanks in advance
- I harvest some infected leaves with S. turcicum patches.
- I dried them during 4 days at 30-35°C.
In which form do you think it is better to conserve it ? Leafs, powder ?
In which conditions ? In a cold chamber ? (6-8°C and H2O%=50%)?
How long can I preserve theses spores in well-adapted storage conditions?
Many thanks in advance for all the answers!
In my case, I'm working with entire root systems of Medicago truncatula infected by an oomycete.
I want to know the methods and procedures for inoculating sawdust at a certain weight and the parameters to measure or take to know if degradation is enhanced.
Which protocol i may follow to preserve plant pathogens at -20 and at -80 degree Celsius specially Rhizoctonia, Alternaria, Bipolaris, Curvularia, Sclerotium, Colletotrichum and Fusarium? we are not using liquid nitrogen based preservation more.
Thanks in advance
I would like to inquire whether someone has been treated fungal cultures by vacuum in a Petri dish? We have found that the agar dries suddenly. This is normal? How can we detect the effect of vacuum and not the desiccation?
I'm working towards a research on Pterocarpus trees on the Palmas del Mar forest at Humacao, we've noticed some white leaves on the seedlings of these trees, I'm having trouble pin-pointing a protocol to start this project. Any suggestions?
Wheat blast caused by Magnaporthe oryzae Triticum pathotype is a fearsome disease first emerged in Bangladesh. It poses serious threat to food and nutritional security of Bangladesh. Scientist fears that this disease may spread to neighbouring Asian countries. We need to isolate the pathogen in infected plants and alternate hosts and thus needs a cheaper and faster protocol.
I want to check chitinase activity of bacteria. Is any indicator dye can be added to observe the result of chitinase production by bacteria easily? If yes, then what should be the pH to be maintained?
I got fungal contamination every time (photo attached) during isolation of Phytophthora infestans. I tried culturing on potato tuber slices, for first few days culture is pure but after 1 week some other fungus grows on it. What is this fungi? What are the causes for this type of contamination and how to avoid this? Thanks in advance.
Please here are some other pictures that I got. May somebody help me with the name of this fungus? I am working on water hyacinth and these pictures come from damage leaves by pathogens
During my experiment (cut stem inoculation technique) to identify the isolate aggressiveness of Macrophomina phaseolina and out of 15, 3 isolates found very aggressive.
Can we go for race identification. If yes, then what procedure i should follow.
The photos were taken in northern Italy at the beginning of September of the current year. The vines are placed in an experimental area and are grown in pots. The lower surface of the leaves is normal. Some entomologists and acarologists exclude that the damage is caused by mites. The damage has a negative impact on the quality of grapes. Did someone note similar damage elsewere and does he know or can hypothesize the cause?
Rapid potato stem damage caused by Phytophthora is spreading this year on some potato cultivars. Is it common symptoms comparing to late blight? Some plants are infected by Pectobacterium spp. together with oomycete, increasing soft rot symptoms. Is it common for green part of potato plant?