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Post by ravendra on Aug 31, 2015 19:00:45 GMT -6
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Post by nathalia on Sept 1, 2015 14:56:17 GMT -6
Great job on the presentation! It was very interesting.
This virus intrigued me because normally viruses survive in a vector or in a host. This one does not have a vector (identified so far). How long could this virus survive in the soil or in water in the absence of a susceptible lettuce cultivar. Also, is there any other host besides lettuce that has been reported?
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Post by ravendra on Sept 2, 2015 11:13:04 GMT -6
Great job on the presentation! It was very interesting. This virus intrigued me because normally viruses survive in a vector or in a host. This one does not have a vector (identified so far). How long could this virus survive in the soil or in water in the absence of a susceptible lettuce cultivar. Also, is there any other host besides lettuce that has been reported? Attached is the publication which distinguished Lettuce necrotic stunt virus from Tomato bushy stunt virus based on the serology and genomic information due to the variation between the two viruses which were earlier thought to be the different strains of the same virus TBSV. PHYTO.2001.91.8.797.pdf (305.29 KB). As far as survival in the soil is concerned in the absense of host, I will post as I find more information.
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Post by ravendra on Sept 2, 2015 11:34:57 GMT -6
Great job on the presentation! It was very interesting. This virus intrigued me because normally viruses survive in a vector or in a host. This one does not have a vector (identified so far). How long could this virus survive in the soil or in water in the absence of a susceptible lettuce cultivar. Also, is there any other host besides lettuce that has been reported? Attached is a nice review article which describes how the soil-borne virus disease- lettuce dieback emerged in the Salinas valley in Caifornia. Lettuce dieback disease has primarily been observed in the areas near rivers in the Salinas valley, CA. Due to heavy rainfall and flooding like conditions in Salinas valley the lettuce dieback disease has progressed rapidly in the last decade. This is soil-borne disease with no identified fungal or any other vectors. The literature suggests pretty long survival of the Lettuce necrotic stunt virus in the soil but don't state a specific time-period. I think, the reason would be relatively shorter period of investigation into this disease. Review article on virus disease management ....pdf (388.28 KB) |
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Post by ravendra on Sept 2, 2015 11:41:20 GMT -6
Great job on the presentation! It was very interesting. This virus intrigued me because normally viruses survive in a vector or in a host. This one does not have a vector (identified so far). How long could this virus survive in the soil or in water in the absence of a susceptible lettuce cultivar. Also, is there any other host besides lettuce that has been reported? Yes, the Lettuce necrotic stunt virus has a wide host range similar to the other tombusviruses. The host range lies within multiple families including Amaranthaceae, Brassicaceae, Apiaceae, Chenopodiaceae, Compositae, Caryophyllaceae, and Cucurbitaceae. In most of the cases the virus produces local lesions in the inoculated leaves. One of the papers attached in above posts has all the detailed information on the host range studies carried out. |
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Post by gabriela on Sept 4, 2015 14:08:50 GMT -6
The presentation was great and I really liked, I think that personalty I learned a lot of the Lettuce die back disease 1) Soil treatment? I was really impress to know that this virus could stay in the soil and wait for the host to just produce the infection. I was reading, to see if is possible to get rid of the virus or fungi that stays in soil, and I found a technique, that I don't know if you guys are familiar with and I really not sure if it would be possible with viruses. this technique is called: Soil steam sterilization (soil steaming). This is a farming technique that sterilizes soil with steam in open fields or greenhouses. The pests are killed through induced hot steam which causes their cell structure to physically degenerate.Is this possible in viruses?? well this method is mostly considered as a "partial disinfection" In the case of some fungi and bacteria (that actually survive in soils as spore-forming) some of them survive and then the disease gets actually worst. So that makes me think, is this type of virus heat shock resistant? do they have structures that let them survive in the soil? as camouflage? 2) Hydroponic Lettuce I found this video, where is actually showing how the hydroponic system of lettuce work: www.youtube.com/watch?v=aJ7XAvVUh8wI found video referring to the water treatment in hydroponic systems: ELIMINATION OF ROOT-INFECTING PATHOGENS IN RECIRCULATION WATER FROM CLOSED CULTIVATION SYSTEMS BY ULTRA-VIOLET RADIATION. The paper is not free..so I couldn't actually download the PDF but if you go to this link you could be able at least to read the abstract: www.actahort.org/members/showpdf?booknrarnr=361_36 |
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Post by omararias on Sept 5, 2015 9:35:41 GMT -6
Hi everyone, Here is the presentation that I made on lettuce dieback disease. Nice presentation. Please, I have one question, so far is there any specific virus mechanism movement through the water and soil?, I mean how can the virus transport and survive through this means. Besides of the US, is there any country in which this virus has shown a huge impact in terms of agricultural losses? Thanks. |
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Post by omararias on Sept 5, 2015 9:55:06 GMT -6
I have another question, please, besides of the treatment with bromide and chloropicrin that you talked in the presentation and the ultra violet radiation that Gaby mentioned. Is there any molecular mechanism for tolerance against this virus like for instance, developing of some type of resistance, like genetically modified lettuce.
Thanks.
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Post by omararias on Sept 5, 2015 10:04:41 GMT -6
The presentation was great and I really liked, I think that personalty I learned a lot of the Lettuce die back disease 1) Soil treatment? I was really impress to know that this virus could stay in the soil and wait for the host to just produce the infection. I was reading, to see if is possible to get rid of the virus or fungi that stays in soil, and I found a technique, that I don't know if you guys are familiar with and I really not sure if it would be possible with viruses. this technique is called: Soil steam sterilization (soil steaming). This is a farming technique that sterilizes soil with steam in open fields or greenhouses. The pests are killed through induced hot steam which causes their cell structure to physically degenerate.Is this possible in viruses?? well this method is mostly considered as a "partial disinfection" In the case of some fungi and bacteria (that actually survive in soils as spore-forming) some of them survive and then the disease gets actually worst. So that makes me think, is this type of virus heat shock resistant? do they have structures that let them survive in the soil? as camouflage? 2) Hydroponic Lettuce I found this video, where is actually showing how the hydroponic system of lettuce work: www.youtube.com/watch?v=aJ7XAvVUh8wI found video referring to the water treatment in hydroponic systems: ELIMINATION OF ROOT-INFECTING PATHOGENS IN RECIRCULATION WATER FROM CLOSED CULTIVATION SYSTEMS BY ULTRA-VIOLET RADIATION. The paper is not free..so I couldn't actually download the PDF but if you go to this link you could be able at least to read the abstract: www.actahort.org/members/showpdf?booknrarnr=361_36Those treatments are very interesting, please, according to what you have been reading, do you know which mechanism works better in terms of efficiency?, and is it possible to present collateral damage, like secondary effects (for example: low rate of nutrients in the lettuce, affectation in human consumption) in the cultivar itself when applying UV light?. Thanks. |
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Post by ravendra on Sept 5, 2015 10:16:17 GMT -6
The presentation was great and I really liked, I think that personalty I learned a lot of the Lettuce die back disease 1) Soil treatment? I was really impress to know that this virus could stay in the soil and wait for the host to just produce the infection. I was reading, to see if is possible to get rid of the virus or fungi that stays in soil, and I found a technique, that I don't know if you guys are familiar with and I really not sure if it would be possible with viruses. this technique is called: Soil steam sterilization (soil steaming). This is a farming technique that sterilizes soil with steam in open fields or greenhouses. The pests are killed through induced hot steam which causes their cell structure to physically degenerate.Is this possible in viruses?? well this method is mostly considered as a "partial disinfection" In the case of some fungi and bacteria (that actually survive in soils as spore-forming) some of them survive and then the disease gets actually worst. So that makes me think, is this type of virus heat shock resistant? do they have structures that let them survive in the soil? as camouflage? 2) Hydroponic Lettuce I found this video, where is actually showing how the hydroponic system of lettuce work: www.youtube.com/watch?v=aJ7XAvVUh8wI found video referring to the water treatment in hydroponic systems: ELIMINATION OF ROOT-INFECTING PATHOGENS IN RECIRCULATION WATER FROM CLOSED CULTIVATION SYSTEMS BY ULTRA-VIOLET RADIATION. The paper is not free..so I couldn't actually download the PDF but if you go to this link you could be able at least to read the abstract: www.actahort.org/members/showpdf?booknrarnr=361_36Gaby, thanks for the information. As far as I know, soil solarization works for some viruses in the family Potyviridae. Wheat streak mosaic virus which was earlier classified as a potyvirus but now is the type member of tritimovirus genus in Potyviridae is an example where soil solarization has been successfully utilized to reduce the virus spread in the wheat. This research has been recently done at Texas AgriLife Research station in Amarillo and I attended that presentation in Southern APS meeting in Dallas last year. Soil solarization also works for some nematode diseases in leafy vegatables. I don't know yet if soil solarization works for lettuce dieback. But, I will get back to the forum and let you guys know if I come up with any information on that. Thanks, for your input., That was really awesome.
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Post by ravendra on Sept 5, 2015 10:24:42 GMT -6
Hi everyone, Here is the presentation that I made on lettuce dieback disease. Nice presentation. Please, I have one question, so far is there any specific virus mechanism movement through the water and soil?, I mean how can the virus transport and survive through this means. Besides of the US, is there any country in which this virus has shown a huge impact in terms of agricultural losses? Thanks. Omar, thank you for asking that question. Lettuce necrotic stunt virus is reported to be transmitted through water and soil. Flooding like conditions especially in Salinas valley in California were reported to be one of the reasons of virus spread, I had attached that paper in earlier posts. Besides US, this virus has been reported from Morocco and Spain as well. |
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Post by ravendra on Sept 5, 2015 10:29:50 GMT -6
I have another question, please, besides of the treatment with bromide and chloropicrin that you talked in the presentation and the ultra violet radiation that Gaby mentioned. Is there any molecular mechanism for tolerance against this virus like for instance, developing of some type of resistance, like genetically modified lettuce. Thanks. Yes, TvrI is the gene which has been utilized for developing Lettuce necrotic stunt virus resistant cultivars. Please find attached the link to the paper which describes marker assisted selection for TvrI in detail. www.biomedcentral.com/1471-2229/9/135
Sorry that I couldn't attach the pdf because of larger size than permitted.
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Post by gabriela on Sept 6, 2015 14:21:11 GMT -6
Dear Omar, in terms of efficiency I couldn't find which treatment is better than the other one in terms of UFC or pathogen's elimination. However, in economic terms, solarization process are less expensive and for that reason they are more use. No even biodegradable plastics and films are being used for efficiency and for environment friendly terms.
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Post by gabriela on Sept 6, 2015 14:38:20 GMT -6
Thanks so much Ravendra, I was just wondering about this information. If soil solarization is possible, and cost effective that would benefit high number of farmers avoiding huge economic losses.
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Post by ravendra on Sept 7, 2015 13:35:16 GMT -6
www.sciencedaily.com/releases/2011/01/110118101606.htmThe above link to Science News released on February 17, 2011 that mentioned new breeding lines of Romaine lettuce developed in California to have disease resistance against Lettuce necrotic stunt virus. The article mentioned that California and Arizona together account for more than 95% of lettuce production in United States and the virus had been responsible for approx. 60% crop losses resulting in major setback to the growers. The work was published in HortScience: Ivan Simko, Ryan J. Hayes, Krishna V. Subbarao, and Rebecca Grube Sideman. SM09A and SM09B: Romaine Lettuce Breeding Lines Resistant to Dieback and with Improved Shelf Life. HortScience, 2010; 45: 670-672.
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