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Questions related from Alex Ignatov
Horsetail (Equisetum arvense) is the plant very resistant to Glyphosate. After weeds were killed by the herbicide, it rapidly propagates and maintains high number per area despite the presence of...
10 August 2023 6,776 2 View
Prof. Van der Wolf with colleagues (2005)* wrote that for "... Clavibacter michiganensis no data on transmission via nematodes are available". Dr. Osdaghi (2022)** in the most recent review of...
05 August 2023 7,752 3 View
Leaves of several plant species lost chlorophyll after infestation by Spanish slugs (Arion vulgaris). Is it specific slug toxin or some specific virus vectored by the slug?
30 July 2023 2,179 5 View
There are many cases of natural transformation by Agrobacterium that gave beneficial phenotypes of agricultural crops. It is reviewed by Desmet, S., Dhooghe, E., De Keyser, E. et al. Rhizogenic...
10 June 2023 5,602 1 View
Chantal Jeanne Beauchamp with colleagues (1990) (Fungal Catabolism of Crown Gall Opines) described fungi capable to utilize several opines as their sole carbon and nitrogen source. Is it possible,...
24 May 2023 5,354 1 View
Tomato disease (Blue mold of tomato) caused by Penicillium oxalicum was found in Japan at 2009. Umemoto, S., Odake, Y., Takeuchi, T. et al. Blue mold of tomato caused by Penicillium oxalicum in...
25 March 2023 8,038 1 View
"Crazy roots" pathogen, Agrobacterium bv1 with Ri plasmid, change plant roots geotropism. Any idea how the pathogen makes it?
14 March 2023 1,208 10 View
Several broccoli plants in one plot have abnormal shoots proliferation - more then 30 shoots above ground. It has obvious underground too - see the pictures. Is it disease or genetic disorder? It...
18 September 2022 4,893 6 View
Some strains of Pectobacterium sp. are known to produce Trimethylamine, responsible for "fishy" smell of infected plants. Such bacteria were very rare in Northern countries until recent years....
25 August 2022 9,170 0 View
Several reports of viroids infection outside thier host plants are sometimes disputed (Serra P, Carbonell A, Navarro B, Gago-Zachert S, Li S, Di Serio F, Flores R. Symptomatic plant viroid...
25 August 2022 2,779 0 View
Potato plants with normal growth expressed such symptoms as day temperature arised till 30oC. Do you know such virus symptoms on potato?
03 July 2022 8,830 2 View
Miracle F1 (cauliflower, Bejo Zaden ) was used as Xanthomonas campestris races differential variety with proposed gene R3 (Taylor JD, Conway J, Roberts SJ, Astley D, Vicente JG. Sources and origin...
07 May 2022 6,959 0 View
Gram-negative bacterial pathogens interact with the host cells by using type III secretion systems (T3SS) to inject virulence proteins into cells. NleB effectors are glycosyltransferases that...
02 April 2022 7,428 2 View
Young tomato plants in the greenhouse nursery have rotted the middle part of the leaves. The pathogen is obviously systemic (vein-spreading). Is it familiar to anybody?
23 January 2022 1,935 7 View
Several tomato plants in the hydroponic greenhouses are dwarf, bushy, with changed flowers (see pics), no fruits formed from the changed flowers. They are free of usual viruses. What can it be? I...
21 January 2022 2,968 8 View
Phytoplasma seed transmission is a controversial issue despite some evidence: Phytoplasma Transmission by Seed: Transmission and Managemen... Nečas T, Mašková V, Krška B. The possibility of ESFY...
15 January 2022 9,529 3 View
Microbacterium paraoxydans is known as a pathogen (Laffineur K, Avesani V, Cornu G, Charlier J, Janssens M, Wauters G, Delmee M. Bacteremia due to a novel Microbacterium species in a patient with...
08 December 2021 990 4 View
Spray-induced gene silencing, SIGS, is tested for plant diseases control. Is there any results on dsRNA formulation trials that showed long life for dsRNA in a product and an efficient transport...
30 July 2021 4,894 5 View
About 1/4 of field was affected by white heads symptoms. What can it be? Temperature range was high: 5 (night) - 30oC (day) within 4 last weeks.
25 May 2021 6,319 4 View
Clavibacter michiganensis susp. michiganensis was recovered from damaged lettuce seedlings in greenhouse and confirmed by PCR with two different methods. I have heard about natural infection of...
24 July 2020 169 6 View
Potato plants free of 5 common viruses (PVY, PVX, PVS, PVM, PLRV) have unusual symptoms. What can it be?
05 June 2020 6,890 19 View
It is stated in https://www2.ipm.ucanr.edu/agriculture/tomato/tomato-yellow-leaf-curl/ that TYLCV can infect a wide range of plant species, including peppers (Capsicum annuum), eggplants,...
21 May 2020 1,874 3 View
Barley plants, local winter cultivar Dostoynyi has leafspots, what can cause the disease? 3 weeks ago field was treated by Tribenuron-methy 75%, 0.02 g per ha. Seeds were treated by Tebuconazole....
16 May 2020 502 0 View
Low accumulation of Boron (B) cause physiological damage in many plants. High concentration of soluble Ca in soil (over 6 g/kg) and acidic pH (4.5-5) prevent accumulation of B despite sufficient...
25 January 2020 5,282 3 View
Carrot plants suffer from acute B-deficiency (
27 December 2019 6,534 3 View
Tomato plant have severe damage of fruits and young leaves. Mosaic pattern on leaves and necrotic symptoms on fruits, leaves, and petioles. Its it Tomato brown rugose fruit virus ? I have seen...
06 November 2019 6,081 18 View
There is a task to identify rapidly current variants of potyviruses in potato and tomato plants. What would yo recommend - NGS or Sanger method to make it faster? If NGS, what method shell we use...
07 October 2019 9,602 2 View
Pseudomonas corrugata causes pith necrosis of tomato, diseases of chrysantemium, geranium plants, isolated from roots of other crops, and applyed as biocontrol method against plant pathogenic...
23 May 2019 9,523 13 View
Young rose plants have chlorosis on leaves and slow growth comparing to healthy ones. What is the reason? Greenhouse plants are grown under controlled (optimal) temperature, humidity, light, and...
10 January 2019 9,304 11 View
The EU Court of Justice has ruled that plants created using novel genome editing methods will be classed as genetically modified organisms and therefore have to follow the strict EU guidelines for...
29 July 2018 3,784 34 View
Sunflower young plants show retarded growth, surface necrosis and cracks of undersoil stem part, necrosis of leaf petioles, young top leaves are dead. There is no evidence of bacterial or fungal...
10 June 2018 9,790 8 View
It is known that many pathogenic/parasitic microbes increase resistance to biocides if penetrate host cell. What would happen with Phytophthora infestans?
21 April 2018 4,007 10 View
I have isolated from water some strange-looking colonies on YDC medium. In fact they are dark violet. Do you have any idea about taxonomic position of this bacteria?
25 February 2018 7,921 5 View
For the first time it looks like herbicide damage. Young leaves growth retardation and yellowing have been noticed at the same plot last year, but at later stage of plant development. This year,...
08 July 2015 8,595 29 View
High energy microwave affect iliving beings mainly through termal effect. What is the mechanism of low dose microwave (300 MHz - 300 GHz electromagnetic field) effect on organism: membrane...
18 January 2015 9,692 8 View
There are many articles about root-associated bacteria capable to protect plant from pathogenic fungi causing root rot of cereals. Many of this bacteria belong to plant pathogenic taxa...
30 December 2014 2,485 6 View
I have found recently yellow-pigmented bacterium that cause canker of Physalis leaves at 25-30oC and rapid blight at 35oC. This bacterium cause no symptoms but colonyze plant leaves at
29 August 2014 7,055 4 View
What shell we expect and test plants before founding new grapevine plantations? The list includes 14 viruses: Alfalfa mosaic virus; Arabis mosaic virus; Broad bean wilt virus; Grapevine Algerian...
27 August 2014 3,957 10 View
"The ancient pathogen Pithovirus sibericum (class of giant viruses) was discovered buried 30m down in the frozen ground. The virus infects amoebas. The last time it infected anything was more than...
05 March 2014 3,569 4 View
Agrobacterium bv1 with cucumopine Ri plasmid causes root mat disease of cucumber and tomato in greenhouses. I cannot find any efficient way to reduce the disease on plants and remove the pathogen...
11 February 2014 5,659 14 View
Economic threat of bacterial diseases of cereals is a highly disputed. Some data show potential loss about 40% of yield, others - less than 10% of total losses caused by all diseases
01 February 2014 2,831 2 View
Some DNA sequences localized between CRISPRs repeats of plant pathogenic bacteria are more similar to plant pathogenic viruses than to bacteriophages. Does it mean that plant viruses have infected...
18 January 2014 7,376 6 View
Wheat and barley plants infected by wheat streak mosaic virus and other viruses with clear yellow and even necrotic lesions have very small population of bacteria (Pantoea sp., Pseudomonas sp.)...
09 January 2014 871 4 View
Andree Hubber (2004) described effector-coding genes with signal aa for both T3SS and T4SS.
24 November 2013 6,383 3 View
Has anybody confirmed presence of N-gene of resistance to TMV in tobacco accession CV-58 (PI 551316 Nicotiana tabacum L. SC 72, NC403, T.W. Graham, J.F. Chaplin, Z.T. Ford, R.E. Currin. 1974....
01 January 1970 2,764 2 View
