Feeds:
Posts
Comments

Archive for the ‘Plant Pathogens’ Category

cbu-articles-banner

Development of Powdery Mildew Resistant Tomato via CRISPR-Cas9

In tomato (Solanum lycopersicum), there are sixteen Mlo genes, with SlMlo1 being the major contributor to the susceptibility to the powdery mildew caused by Oidium neolycopersici. Natural loss-of-function slmlo1 mutants are available in tomato, however, introgression of such mutations is a lengthy process. The team of Vladimir Nekrasov from the Sainsbury Laboratory, Norwich Research Park in the UK aimed to generate a transgene-free genetically edited slmlo1 tomato using the CRISPR-Cas9 system.

The team targeted the SlMlo1 locus using the double sgRNA strategy. Transformants were analyzed and eight out of ten tested T0 transformants indicated the presence of mutations. Assays using the powdery mildew fungus revealed that all the generated T0 slmlo1 mutant plants were resistant to the pathogen, while wild-type plants were susceptible.

Furthermore, the slmlo1 mutant plants were morphologically similar to the wild type and also produced harvested fruit weight similar to the wild types. The team named the generated variety Tomelo. This study presents evidence for CRISPR-Cas9 being a highly precise tool for genome editing in tomato.

For more on this study, read the article in Nature.

Read Full Post »

Huanglongbing (HLB), also known as Citrus greening, has been confirmed in Trinidad for the first time. The disease, which was detected on leaves from a lime tree in the north of the island, can cause devastating yield loss for Citrus growers and is regarded as one of the most important threats to global commercial and […]

via Citrus greening detected in Trinidad — The Plantwise Blog

Read Full Post »

fresh plaza logo

Costa Rica leads the way in preventing banana fusariosis

The International Regional Agency for Agricultural Health (OIRSA), the Ministry of Agriculture and Livestock of Costa Rica, through the State Phytosanitary Service (SFE) and the National Banana Corporation (CORBANA) – among other institutions – are leading the way in the Prevention of fusariosis or wilt by fusarium in banana and plantain plantations. The tropical race 4 of Fusarium oxysporum f. sp.cubense Is the main threat to these crops in the continent, which is why it is classified as quarantine pest of first level importance.
The entry of this pest to the continent would involve changing the production system of the entire surface, as the Cavendish-type materials are highly susceptible to it and the prognosis involves the change of varieties and a series of strategic measures to prevent or eradicate outbreaks, and contain the spread of the pest. Currently, in Costa Rica there are 42,717 hectares planted with bananas for export, according to data from the Executive Secretariat for Agricultural Sector Planning, SEPSA. The main strategy against the Foc R4T is its exclusion, so it is important to monitor and remove suspicious or positive materials from the disease.
In Costa Rica and other countries of the OIRSA region – such as Mexico, Honduras or Guatemala – exclusion and preventive measures are carried out through national technical groups composed of specialists and officials. Biosafety and research on Foc R4T in Mesoamerica is led by Costa Rica, with work done at CORBANA.
In turn, the national technical groups, Ministries of Agriculture and the private sector of the countries have the advice of the Latin American command for prevention and attention to possible outbreaks of Foc R4T and other quarantine pests, which is made up of experts from different institutions or agencies, including the Brazilian Agricultural Research Corporation (EMBRAPA), the National Service of Sanitation, Food Safety and Food Safety (SENASICA), the Plant Protection Institute of Cuba and OIRSA.
One of the priority tasks of the command is to update the contingency plans to minimize the risk of introduction or be prepared to eliminate outbreaks. To strengthen the capacity of exclusion or quarantine measures professionals are trained in ports, airports. To evaluate the capacity of prevention and attention to outbreaks of Foc R4T, simulations of the diagnosis of the disease, the elimination of outbreaks, and the confinement of affected areas, among others, are being carried out. To date, simulations have been carried out in Mexico, Ecuador, and Colombia. During 2017 there will be simulations held in Costa Rica and in all countries of the OIRSA region. The drills are also part of the training in biosafety measures that are currently being socialized at farm level and in larger areas.
A program for the dissemination of printed documents, audio-visual documents and computer applications is being prepared for the transfer of technology and knowledge. Costa Rica has a dissemination program, through the SFE and CORBANA, as well as academic institutions, that allows the socialization of strategies to sensitize producers, exporters and the general public in order to minimize risks of introduction of this pest. Strengthening the economic capacity to face an emergency declared by a Ministry of Agriculture is also a priority for the OIRSA, which is why the Agency is ready to act within less than a week to operate the national plans for the elimination of outbreaks in any country in the region.

Publication date: 7/11/2017

 

Read Full Post »

EPPO Reporting Service 2017 no. 6- Diseases

2017/117 First report of ‘Candidatus Liberibacter asiaticus’ in Panama

In February 2016, ‘Candidatus Liberibacter asiaticus’ (associated with huanglongbing – EPPO A1 List) was detected for the first time in Panama. The disease was found on citrus the areas of Guabito and Las Tablas (district of Changuinoa, province of Bocas del Toro). The Ministry of Agriculture has declared a state of phytosanitary emergency and a national contingency plan has been elaborated to contain the disease and its vector, Diaphorina citri (Hemiptera: Liviidae – EPPO A1 List). In July 2016, 101 citrus plants at the sites where the disease was found were destroyed (burnt). In addition to plant destruction and surveys, the development of a national certification scheme for the production of healthy planting material of citrus has been undertaken. The situation of ‘Candidatus Liberibacter asiaticus’ in Panama can be described as follows: Present, only in some areas (province of Bocas del Toro), under official control.

Source: INTERNET Gobierno de la República de Panamá – Noticias (2017-06-05) Más de B/. 1 millón invertirán Panamá y Taiwán en proyecto para control de la enfermedad de los cítricos HLB. http://mida.gob.pa/noticias_id_4875.html – Noticias (2017-06-02) Sector public y privado analizan normativa de viveros cítricos. http://mida.gob.pa/noticias_id_4495.html – Noticias (2016-08-16) MIDA y Embajada de China (Taiwan) coordinan proyectos técnicos. http://www.mida.gob.pa/noticias_id_3977.html – Noticias (2016-07-25) Decomisan plantones de cítricos en puesto de control de cuarentena en Hornitos. http://mida.gob.pa/noticias_id_3898.html – Noticias (2016-06-01) MIDA impulsa plan de emergencia para control de enfermedad en los cítricos. http://www.mida.gob.pa/noticias_id_3739.html República de Panamá. Ministerio de Desarrollo Agropecuario. Resolucion no. OAL039-ADM-2016 of 2016-02-03. Gaceta Oficial Digital, jueves 17 de marzo de 2016 no. 27991. http://extwprlegs1.fao.org/docs/pdf/pan163996.pdf

Pictures: ‘Candidatus Liberibacter asiaticus’. https://gd.eppo.int/taxon/LIBEAS
Additional key words: new record Computer codes: LIBEAS, DIAACI, PA

Read Full Post »

A plant assistant of Plant Clinic in Rohal Suong is recently recruited as an agricultural extension worker for her commune. Women can help reach more sectors in the communities. Photo: Dyna Eam (WorldFish)

Greater involvement of women in plant clinics has improved the climate resilience of the farmers in Rohal Suong village, Cambodia. Women farmers play a critical role in agricultural production and food security, as well as household welfare in most Southeast Asian countries. According to a Census of Agriculture in Cambodia in 2013, of the 82% of Cambodians engaged in the agriculture sector, at least half of them were women.

Female youth and women, however, have limited access to education, agricultural extension services and social events, as they often have low education backgrounds, and are frequently busy with household activities and other unpaid work. They are historically underrepresented in agriculture decision-making and community leadership as well.

Agricultural development projects are now seeking to increase women’s involvement. The CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), aims to improve gender equality and women farmers’ decision-making in agriculture through the establishment of Climate-Smart Villages (CSVs). Rohal Suong Village in Battambang, Cambodia is one of the six CSVs in Southeast Asia.

As such, the Rohal Suong CSV has emphasized the inclusion of women farmers in its activities and strategies, such as the Plant Clinic. Operating since June 2016, it is a meeting place where plant advisors and assistants help farmers who are faced with issues of plant pests and diseases. The Clinic has been supported by WorldFish and Center for Agriculture and Bioscience International Southeast Asia (CABI-SEA). Plant advisors and assistants, who are trained through CABI’s Plantwise program, provide diagnoses, treatment advice and recommendations to farmers. Women farmers are encouraged to join the program.

Training and field practices on rice pest and diseases provided by Cambodia’s General Directorate of Agriculture and CABI’s Plantwise program.  Women farmers join the program. Photo: Dyna Eam (WorldFish)

The Plant Clinic is currently led by plant advisors from Battambang Provincial Department of Agriculture and Aphivat Strey (AS), a local NGO, and supported by plant assistants. Plant assistants who are recruited from local farmers play an important role in engaging local farmers to bring their crop issues to the clinic and also in following up with client farmers.

One woman farmer, Ms Savet, was recruited to join the Plant Clinic as a plant assistant. Through her involvement in the project, she has learned several things, such as plant disease identification, plant treatment, and community engagement. She has also had more opportunities to work closely with other community committees and to deliver services to local farmers, particularly other women. Ms Savet was not only able to help local farmers to improve their plant management technique, but has also applied the techniques and treatment methods she learned on her own farm.

I am so happy to work as a plant assistant because I have learned many things about plant disease, pest and treatment methods from the plant advisers and trainings, such as training in Phnom Penh. Now I can provide the advice on some plant diseases to my villagers,” said Ms Savet.

As a result of her experience in the project, Ms Savet has been recruited as an agricultural extension worker for her commune. Now, she is organizing groups of community members for an agricultural demonstration project run by the Battambang Provincial Department of Agriculture, Forestry and Fisheries, and the Agriculture Services Programme for Innovation Resilience and Extension (ASPIRE). ASPIRE is a program of the Ministry of Agriculture, Forestry, and Fisheries, and is funded by the International Fund for Agricultural Development.

I thought that I was recruited as a commune extension worker because I could answer well the questions from examination committees, actually this knowledge came from my experiences at Plant Clinic,” added Ms Savet.

She is now trying to understand the common and different needs of women and men famers in agriculture. Ms Savet is keen to learn more about agricultural technologies and extension service methods, and to transfer her knowledge to her villagers.

Engaging local farmers through the Plant Clinic and extension work is an approach that has helped to successfully build local farmers’ capacities and also help local farmers, particularly women farmers, to get better access to agricultural services. In doing so, the project has helped improve the livelihoods of farming households and increase the resilience of agriculture-dependent communities.

By Dyna Eam. Reblogged from the CGIAR CCAFS blog. Read the original here→

Read Full Post »

Phys Org

Researchers identify protein target to halt citrus tree disease

June 7, 2017

University of Florida researchers may have come a step closer to finding a treatment for a disease called Huanglongbing, or citrus greening, that has been decimating citrus trees in the state. In work published this week in mSphere, an open access journal from the American Society for Microbiology, the investigators describe identifying a small protein from one bacterium living in Asian citrus psyllids—the flying insects that spread the disease as they feed on the trees—that can “cross-talk,” moving to another bacterium within the insects to silence so-called “prophage genes” containing viral material in the second bacterium, helping prevent an insect immune reaction that would likely be detrimental to both bacteria.

The , from the Wolbachia bacterium, could serve as a potential target to develop spray treatments to protect trees against the psyllids, and could potentially help the trees themselves fight off bacterial invasion, said senior study author Dean W. Gabriel, Ph.D., a professor of Plant Pathology at the University of Florida in Gainesville. Wolbachia is a natural bacterium present in up to 60 percent of all insect species. (image: citrus greening disease on mandarin oranges, wikimedia commons)

“In this case, one bacterium is doing a favor to the whole bacterial community living within the psyllid by shutting down a potential threat to survival of insect host,” Gabriel said.

Gabriel and colleagues had been looking for ways to interrupt , a disease process caused when psyllids carrying but not affected by a bacteria called Candidatus Liberibacter feed on healthy trees and inject this bacteria into the trees’ phloem, a tubular system normally used to transport sugars produced during photosynthesis from the leaves of a plant to the rest. The bacterium suppresses the plants’ defenses as it moves, Gabriel said: “It’s like a little cunning burglar sneaking in under the radar.” It impacts the tree from its roots to its shoots, he said, and has a long incubation period: “By the time disease is detected in one tree, the entire grove is thoroughly infested and much more difficult to treat.”

Citrus greening causes a severe decline in the —leaves turn a blotchy, mottled yellow color, the fruits produced are smaller and have an off-taste, and fruit yield is much reduced. The disease has devastated Florida over the last 10 or so years, Gabriel said. As a result, the state’s overall citrus production has declined by about 60 percent over the last six years. Scientists have been desperately seeking a cure.

In a series of laboratory experiments, Gabriel’s team discovered that expression of proteins that help drive the spread of the Candidatus bacteria were suppressed when they were treated with extracts from the psyllids. Further studying the process, they identified a fragment of the protein doing part of suppression as encoded by the Wolbachia strain and secreted into the insect. This protein could move within the insect into the Candidatus bacteria causing greening, bind itself to a genetic region that would normally promote prophage activity, and repress these genes.

Gabriel’s group has a grant from the U.S. Department of Agriculture to grow the Candidatus Liberibacter bacterium in culture, a process that has been difficult because, once removed from its host, the bacterium historically has destroyed itself. Now that a protein target has been identified, it can be commercially synthesized and added to culture media, where the may be more likely to grow, Gabriel said.

Explore further: Blue-bellied insects may play a role in the fight against citrus greening

Read more at: https://phys.org/news/2017-06-protein-halt-citrus-tree-disease.html#jCp

Read Full Post »

The spread of pests and pathogens that damage plant life could cost global agriculture $540 billion a year, according to a report published on Thursday. The report, released by the Royal Botanic Gardens (RBG) at Kew in London, said that an increase in international trade and travel had left flora facing rising threats from invasive […]

via Pests and pathogens could cost agriculture billions — The Plantwise Blog

Read Full Post »

Older Posts »