Archive for the ‘Host plant resistance’ Category

Washington State University News
September 15, 2014
By Eric Sorensen, WSU science writer
PULLMAN, Wash. – Washington State University researchers have found “the most famous wheat gene,” a reproductive traffic cop of sorts that can be used to transfer valuable genes from other plants to wheat.
The discovery clears the way for breeders to develop wheat varieties with the disease- and pest-resistance traits of other grasses, using a legion of genetic tools that can reduce crop losses and pesticide use while foregoing the cost, regulatory hurdles and controversy of genetically modified organisms, or GMOs.
“The real exciting part of this gene is that it has tremendous potential for application,” said Kulvinder Gill, a WSU professor, who reports his findings in the journal Proceedings of the National Academy of Sciences.
For some 35 million years, the wild ancestors of wheat routinely traded genes as they accidentally cross-bred with each other. But with the rise of agriculture and cultivated wheat 10,000 years ago, the plant’s genetic structure changed. Instead of being diploid, with two sets of chromosomes like humans and most other living things, it became polyploid, with, in the case of bread wheat, seven sets of six related chromosomes.
Starting in 1958, just five years after the discovery of DNA’s double-helix structure, researchers suspected that a specific gene controls the orderly pairing of wheat chromosomes during reproduction.
“If this gene was not present, there would be chaos in the nucleus,” said Gill. “Six chromosomes would pair with each other and sometimes five chromosomes would go to one cell and one to the other, resulting in a sterile plant. Because of this gene, wheat can be fertile. Without this gene, it would be more like sugar cane, where it is a mess in the nucleus and it can only be vegetatively propagated.”
But the gene also prevents wheat from breeding with related ancestors that can contain a vast array of traits preferred by growers.
“This gene would not allow rye chromosomes to pair with wheat,” said Gill. “We cannot get a single gene transfer into wheat as long as this gene is present.”
Interest in the gene, called Ph1, has spawned scores of research papers, making it what Gill called, “the most famous wheat gene.”
In 2006, British researchers writing in the journal Nature said they identified the gene.
“In this paper,” said Gill, “we show that their gene is not the Ph1.”
Knowing their findings would be controversial, Gill and his colleagues spent a year repeating the experiments that led to their conclusion. They are now moving on.
“Now that we have the gene, we can actually use that gene sequence to temporarily silence the gene and make rye and other chromosomes pair with wheat and transfer genes by a natural method into wheat without calling it GMO,” Gill said.
Their first effort involves transferring a gene from jointed goatgrass, a wild relative of wheat, to confer resistance to stripe rust. The fungus is considered the world’s most economically damaging wheat pathogen, costing U.S. farmers alone some $500 million in lost productivity in 2012.
While facilitated by technology, the actual exchange of genetic material is similar to what has long taken place in nature, only faster. Incorporating the gene transfer into the overall breeding process, researchers can develop a new variety in five years, said Gill.
“If we let wheat evolve for another few millions years in the wild, maybe it will develop enough variation, but we don’t have that kind of time,” said Gill. “We need to solve this problem today.”
Funding for the research came from WSU’s Vogel Endowment Fund. Other researchers were Ramanjot Bhullar, a WSU doctoral student and the paper’s lead author; Ragupathi Nagarajan, a WSU doctoral student; Harvinder Bennypaul of the Canadian Food Inspection Agency; Gaganpreet K. Sidhu, a WSU master’s graduate now at Columbia University; WSU doctoral student Gaganjot Sidhu; WSU assistant research professor Sachin Rustgi; and R.A. Nilan Distinguished Professor Diter von Wettstein.

Kulvinder Gill, WSU professor, ksgill@wsu.edu, 509-335-4666


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[CAPE TOWN] Researchers in Zurich, Switzerland, have successfully developed a strain of virus-resistant cassava, and now hope to train scientists in Africa to develop the technology in laboratories on the continent.

The study, which demonstrated that researchers can now generate transgenic farmer- and industry-preferred cassava, was published in PLOS One last month (25 September).

Herve Vanderschuren, the study’s lead author, and head of the cassava research team at the Swiss Federal Institute of Technology (ETH) in Zurich, said the research team had developed a new cassava variety that is resistant to cassava mosaic disease and cassava brown streak virus, an infection that makes cassava roots unpalatable.

These two major viral diseases reduce cassava production in large areas of Sub-Saharan Africa.

According to the UN Food and Agriculture Organization, cassava is currently the third most important source of calories in the tropics, after rice and maize, and more than 800 million people use cassava as a source of food and income generation in Africa, Asia, and Latin America.

The new strain is drought tolerant and can grow in a range of agro-ecosystems — including less fertile soils — ensuring that when other crops fail, cassava can still be harvested.

“We are going to establish the technology in African laboratories, and have local scientists develop them there,” Vanderschuren told SciDev.Net.

Despite limited funding, the team were already transferring technology through funded trainings to laboratories in Kenya, Tanzania and South Africa, and were working to ensure that scientists in Africa were becoming adept at using it, Vanderschuren explained.

He said that empowering local laboratories could help change the views of some African governments on genetically-improved crops, as previously they had not been in a position to ‘own’ or monitor the technology, but now would be.

How soon the new cassava strain would be available to farmers was still not clear, Vanderschuren said, as key stages, including product development and local authority engagement, still needed to be undertaken.

On a wider level, Vanderschuren encouraged raising the level of debate to ensure improvements in the transfer of technology from North to South.

“If we are to guarantee that this technology spreads among scientists in Africa, researchers must share knowledge on genetically-modified cassava,” said Chrissie Rey, a professor of plant biotechnology at the University of the Witwatersrand, in Johannesburg, South Africa.

Rey said all intellectual property rights owners should be engaged before the technology is rolled out to the farmers. Policy issues must be addressed and GM laws developed to ensure technology can be transferred smoothly into African contexts, she told SciDev.Net.

If these laws were established, she added, they would allow more trials and enable more results from varied field conditions

More field trials were needed to ensure the technology was robust, Rey concluded.

Link to full article in PLoS ONE

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lalitpur_fileminimizer_Five years ago, diseases and storms during the monsoon season would wipe out the majority of Nepali tomato plantations. Discouraged, Nepali farmers slowly started abandoning tomato production. But the tomato is a big part of local cuisine, so Nepal had to import it from India.

Horticulturist Kedar Budhathoki, based in the Lalitpur district, understood Nepali farmers’ problems. He was already leading a team of scientists working to develop a tomato variety that was resistant to the disease wilt. A few years — and many experiments — later, a local hybrid variety, Shrijana, was born.

Demand grew as the fruit remained popular. And Nepali farmers knew they had found a way to flip the export-import equation. Today, 90 per cent of tomatoes in Nepal are Shrijana and Nepal not only produces all its own tomatoes, but it exports them to several neighbouring states in India.

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[LAGOS] Nigerian farmers who tested new maize crops resistant to the widespread Striga plant parasite are so enthusiastic about their increased crop yields that they are selling more seeds than the official distribution channels.

The crops were developed in the Nigerian laboratories of the International Institute for Agricultural Research (IITA). They dramatically cut maize losses from the root-infecting Striga, or witchweed, during two years of trial cultivation by farmers in Borno State in northern Nigeria.

Nigeria’s Institute for Agricultural Research began distributing the new parasite-resistant maize seeds in December 2008.

Abebe Menkir, the lead scientist on the research project at IITA, told SciDev.Net that some farmers in Borno state were already producing large quantities of resistant seeds and selling them on to farmers in and outside the region. He was unable to say how many seeds are being — and will be — distributed through official channels.

“The farmers say they couldn’t wait for the official release of seedlings because the variety is successful, cutting losses,” says Menkir.

Menkir said the next step was to distribute the parasite-resistant maize in other countries in West and Central Africa.

The varieties, known as Sammaz 15 and 16 contain genes that diminish the growth of parasitic flowering plants such as Striga, which attaches to the maize root. Both Sammaz varieties tolerate heavy Striga infestations without suffering crop losses.

“A normal maize variety without resistance to Striga can sustain from 60 per cent to 100 per cent grain yield loss in farmers’ fields that are severely infested,” Menkir told SciDev.Net. Sammaz 16 loses just ten per cent of yield in an extreme invasion.

Sammaz 16 is a late-maturing variety requiring 110 to 120 days of growth, whereas Sammaz 15 can often be harvested at 100 days and is more suitable for regions with short growing periods or unpredictable water supplies.

Agronomy researcher Michael Aken’Ova from the faculty of agriculture at the University of Ibadan, said that producing resistant and tolerant cultivars such as Sammaz is the most economically feasible, easily accessible, safe and sustainable approach to combat losses due to Striga, particularly compared to labour-intensive methods such as weeding.

He added that he is sure that the resistant crops will soon make it to the farmers who need them, with the aid of leaflets, radio magazine programmes and messages in local languages.

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In 2011, a new maize disease was identified in East Africa. The viral disease, maize lethal necrosis (MLN), has devastated crop yields in those areas in Kenya, Uganda and Tanzania where it was first detected. In parts of Kenya, farmers have lost ‘their entire’ harvest.

In response to the threat this virulent disease poses to food security in East Africa, the International Maize and Wheat Improvement Center, in collaboration with the Kenya Agricultural Research Institute, has opened a research facility in Naivasha, Kenya, to find varieties of maize resistant to MLN. The facility opened in September 2013 and, this March, the first varieties of maize were inoculated with the disease. The initial results have given hope that new hybrid varieties can be created that will be resistant to MLN.

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The Ecologist

2nd August 2014



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Fall armywom larva in a sweetcorn ear.

Photo: Judy Baxter via Flickr






GMO corn varieties that express insecticidal Bt toxins are failing in the field, with reports of infestations of the fall armyworm on Bt corn in Brazil and the USA. Now the EU is poised to approve one of the failing varieties for use on European farms.

There are barely any non-GMO seeds available … it is very uncomfortable that the companies are blaming the farmers.

The Association of Soybean and Corn Producers of the Mato Grosso region (Aprosoja-MT) has complained that its members’ genetically modified ‘Bt corn’ crops are no longer resistant to insect pests.

That’s corn which has been genetically modified to produce an insecticidal toxin that repels or kills pests – principally Spodoptera frugiperda, also known as fall armyworm, corn leafworm or southern grassworm.

The Bt toxin is meant to provide protection to the crop without needing to be sprayed with insecticide. But reports from farmers allege that the Bt corn is actually less resistant to attack by Spodoptera caterpillars than non-GMO varieties.

Now farmers have been forced to apply insecticides to their crops, racking up additional environmental and financial costs – after having already paid a premium price for the GM corn seeds.

Deceptive advertising?

The loss of resistance to Bt corn caterpillars was identified by Aprosoja-MT in March, when the first reports of emerged from Mato Grosso producers frightened by what they saw on the field.

Aprosoja-MT began to gather technical reports with data, photos and economic analysis of producers’ financial losses, estimated at $54 per hectare in terms of extra insecticide and application costs.

The association is now calling on Monsanto, DuPont, Syngenta, and Dow companies to offer solutions as well as compensate the farmers for their losses.

“We want companies point to a rapid solution to the losses and also a way to compensate those who were harmed”, says the president of Aprosoja-MT, Ricardo Tomczyk. “It is a typical case of product that promised an outcome that was never delivered – i.e., deceptive advertising”

Blame the farmers

The association has given the seed companies ten days in which to offer solutions to the problems presented by the GM varieties, as well as a way to compensate the losses faced by farmers in Mato Grosso.

But Monsanto and other seed companies are unlikely to accommodate the farmers. According to Reuters, “seed companies say they warned Brazilian farmers to plant part of their corn fields with conventional seeds to prevent bugs from mutating and developing resistance to GMO seeds.”

However Tomczyk responded that the seed companies instructions on creating insect refugia of non-GMO corn were vague and hard to follow. And in any case, he added, “There are barely any non-GMO seeds available … it is very uncomfortable that the companies are blaming the farmers.”

Aprosoja-MT is attempting to negotiate an agreement with the seed companies, but insists that farmers are ready to sue for their pesticide costs.

Not for the first time

Earlier this year, a similar problem arose in the US, when scientists confirmed that corn-destroying rootworms had evolved to be resistant to the GMO corn engineered to kill them.

And according to the non-profit TestBioTech, the GMO maize 1507 -which may soon be approved for cultivation in the European Union – is one of those now failing in Brazil.

This maize variety, developed by US companies Pioneer/DuPont and Dow, combines a Bt insecticidal protein with tolerance to glufosinate herbicides.

According to a study published in the journal Crop Protection, certain pests in Brazil are becoming resistant to this maize line only few years after market approval.

Farias et al. (2014) found resistant populations of Spodoptera in the federal states Bahia and Rio Grande del Sul. According to the authors, development of resistance in fall armyworm was first noticed in 2012, the third year after the start of cultivation of maize 1507 in Brazil.

Industry response – add more GM traits

The industry response to such loss of efficacy is not to encourage biodiversity, but to further modify the organisms, according to TestBioTech:

“The case of Brazil is an example for an overall trend showing that nearly twenty years after the start of commercialization of Bt crops, there are problems in several countries growing this kind of genetically engineered crop.

“Industry tries to tackle this issue by commercialization of so called ‘stacked traits’ that produce several different Bt toxins. The best known example is Monsanto’s SmartStax maize that produces six different Bt toxins.”

TestBioTech also argues that the European Food Standards Agency should re-consider its likely approval for maize 1507 given the fast developing resistance to it among pests, also citing “fundamental data gaps in risk assessment.”

Further information:

Farias et al. (2014), Field-evolved resistance to Cry1F maize by Spodoptera frugiperda (Lepidoptera: Noctuidae) in Brazil
Industry influence in the risk assessment of genetically engineered Maize 1507 (2014)
Genetically engineered maize 1507 – Industry and EFSA are disguising true content of Bt toxin in the plants (2014)
High-Level-Risk-Maize 1507 (2013)Testbiotech figure: Bt crops: Resistance development in pest insectsA fall armyworm (Spodoptera frugiperda) caterpillar in a sweetcorn cob. Photo: Judy Baxter via Flickr.

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Forjar alianzas de investigación pensando en agricultores

Alianzas reales son clave para unir innovación de vanguardia con usos posteriores dice Jean-Marcel Ribaut del CGIAR.


         Investigación de laboratorio: desconectada de estudios aplicados en otras fases de cadena de I+D

  • Programa del CGIAR los vincula para crear nuevos cultivos para agricultores de escasos recursos

  • Se basa en promoción de enlaces eficaces en vez de alianzas usadas como ‘coartadas’






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Alianzas reales son clave para unir innovación de vanguardia con usos posteriores dice Jean-Marcel Ribaut del CGIAR.
La investigación agrícola para el desarrollo abarca una amplia gama de actividades: desde la investigación de ‘vanguardia’, generalmente realizada en universidades o institutos avanzados de investigación, hasta la investigación mucho más ‘secundaria’ de los fitomejoradores que logran mejores cultivos en los campos de agricultores.
Como resultado de este amplio contexto, las actividades pueden fragmentarse y tener escasa comunicación entre los equipos especializados a lo largo de la cadena de investigación y desarrollo (I+D). Esto a menudo resulta contraproducente, especialmente cuando los investigadores van más allá de su área de especialización.
Además, las cada vez más amplias y diversas carteras de investigación con frecuencia ponen en peligro la eficiencia y crean una competencia desleal para la financiación. Y, en consecuencia, los proyectos de investigación nunca se convierten en productos que mejoren la productividad agrícola.
Las alianzas verdaderas y eficaces —que conectan a la gente adecuada de los equipos complementarios— son un camino obvio para mejorar la efectividad de la I+D.
Vincular la innovación con la aplicación
Vincular las innovaciones de la investigación de avanzada con las aplicaciones posteriores de esa investigación —frecuentemente conocida como ciencia de transferencia o biología de transferencia— no es un reto nuevo. Al menos en el campo del mejoramiento de cultivos, es más fácil decirlo que hacerlo.
Es importante encontrar las personas y los equipos adecuados, y tener financiamiento y recursos humanos suficientes para manejar eficazmente las alianzas, procurando que todos se muevan en la misma dirección y maximizando las sinergias entre los equipos al tiempo que se mantiene la atención en la calidad de la información y el intercambio de información. 
Los Programas de Desafío del CGIAR constituyen un modelo de cómo pueden trabajar eficientemente estas alianzas. Uno de ellos es el Programa Generación, que yo dirijo: un consorcio global de instituciones de investigación de cultivos que, en una década, se propuso demostrar que aplicando biología moderna y aprovechando la diversidad genética de las plantas es posible crear variedades de cultivos que satisfagan las necesidades de los agricultores de escasos recursos.

Un reto esencial de una alianza verdadera es lograr el equilibrio adecuado entre la gestión que sirve al programa en su totalidad y crear compromiso de modo que todos los socios se puedan alimentar del espíritu de red”.

Jean-Marcel Ribaut, CGIAR

Para apoyar las iniciativas de colaboración de los equipos de investigación independientes, en los primeros cinco años (2004-2008)  del programa hubo varias convocatorias para subvenciones. Esto creó una sana competencia a medida que los ganadores eran seleccionados basándose en criterios bien definidos. Un criterio clave fue el de la ‘alianza integradora’: cada proyecto necesitaba tener por lo menos un socio de un instituto de investigación de avanzada, un centro perteneciente al CGIAR y una institución de investigación y/o educación de un país en desarrollo.
A través de un proceso competitivo, el programa también fomentaba la participación activa de socios de países en desarrollo, que facilitaran la adopción sostenible de nuestros productos, descalificando a lo que denominamos alianzas usadas como ‘coartada’, vale decir aquellas donde la participación de los países en desarrollo queda reducida a una actividad y un presupuesto limitados. Cada proyecto también tenía que incluir un componente de creación de capacidades.
Reorientar las agendas de investigación
A la mitad del programa, se reorientó su agenda de investigación para reducir el número de cultivos y países objetivo basándose en criterios como el material genético y genómico potencialmente valioso y disponible de un determinado cultivo y evitando la duplicidad con otras iniciativas.
La segunda fase (2009-2014) esencialmente encargó proyectos para construir resultados prometedores derivados de la primera fase, traduciéndolos en productos tangibles para nuestros usuarios primarios, que principalmente son mejoradores de plantas de los países en desarrollo. Esto se logró con un cambio progresivo en el presupuesto y en el liderazgo de los institutos de investigación avanzada y del CGIAR a través de subvenciones directas a los institutos locales de mejoramiento.
Una iniciativa sobre el sorgo en el que participan científicos de tres regiones (América del Norte y del Sur y África) es un ejemplo de dicho cambio.
En primer lugar, los investigadores dirigidos por un científico de alto rango del Departamento de Agricultura de los Estados Unidos con sede en la Universidad de Cornell, en colaboración con un científico visitante de la corporación de investigación EMBRAPA de Brasil, clonó un gen que confirió tolerancia al sorgo ante la toxicidad del aluminio. Mediante otro proyecto competitivo dirigido por Brasil (en su primera fase), los investigadores examinaron posteriormente un conjunto diverso de material genético de diferentes familias de plantas para identificar las más favorables para el desempeño del sorgo en suelos ácidos con aluminio tóxico.
En un tercer paso, a partir de la construcción de una alianza exitosa y de los productos generados a través de dos subvenciones competitivas, el programa encargó una segunda fase del proyecto colaborativo entre mejoradores africanos y los científicos brasileros que dirigieron el segundo proyecto competitivo. El objetivo fue transferir los genes favorables brasileños en las variedades africanas de sorgo de Kenia y Níger.
De esta manera, este proyecto con múltiples socios de distintos países a lo largo de una década, que comenzó con un experimento de laboratorio en los Estados Unidos, se espera que conduzca a productos para los agricultores africanos en los próximos dos o tres años, con una parada en el intermedio en Sudamérica.
El espíritu de la alianza
Esta es, por supuesto, una de nuestras mejores historias que facilitan la colaboración exitosa a lo largo de la cadena de I+D. Naturalmente, también hubo algunos fracasos, especialmente cuando nos pusimos demasiado legalistas en la nominación de socios que teóricamente pensábamos eran muy adecuados para una actividad determinada. También tuvimos proyectos que generaron productos que resultaron inapropiados para ser transferidos a la cadena de suministro.
Aprendimos que la ‘química’ entre los socios —el hecho de que se aprecien entre sí, construida progresivamente en base a colaboraciones anteriores— es probablemente tan importante, si no es más importante, que las habilidades complementarias que lucen prometedoras en el papel.
Así que, en general, la joya de la corona de nuestros logros es en realidad un espíritu intangible y una cultura basada en la confianza mutua, el respeto y un auténtico deseo de complementar el trabajo —y aprovechar las habilidades—de los otros socios. Así lo afirmó una reciente revisión externa, que calificó muy alto el enfoque de alianzas del programa. [1]
No hay una receta mágica para fomentar este espíritu. La construcción de proyectos prometedores como parte de un trabajo enfocado y encomendado es un ingrediente clave, como lo es el constante deseo de ayudar y, cuando sea posible, pasar el liderazgo al siguiente actor de la cadena de suministro.
Debo añadir una advertencia necesaria: este modelo puede trabajar solo si se construye con instituciones sólidas y bien establecidas, y como un complemento a las actividades básicas.
Otro elemento clave del éxito es identificar aquellos objetivos específicos de la investigación que se puedan alcanzar en un determinado margen de tiempo. Nuestra experiencia también sugiere que los beneficios de tener un equipo de gestión independiente supera el costo que ello conlleva.
Un reto fundamental de una alianza verdadera es lograr el equilibrio adecuado entre la gestión que sirve al programa en su totalidad y crear compromiso de manera que todos los socios se puedan alimentar de un espíritu de red.
Jean-Marcel Ribaut es director del Programa de Desafío Generación del CGIAR, una red de alianzas de fitomejoradores alojada en la sede del CIMMYT en México. Se le puede escribir a: j.ribaut@cgiar.org
La versión original de este artículo se publicó en la edición global de SciDev.Net


[1] Paramjit S. Sachdeva and others Report of the final external review of the Generation Challenge Programme (CGIAR, April 2014)

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