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A team of Japanese researchers has developed a method that combines crossbreeding with next-generation sequencing to speed up the identification of genes that cause agronomically important traits in mutant crop lines. The researchers described the method, called MutMap, in a study published in Nature Biotechnology last month. They also outlined their use of the method to rapidly identify the locations of genes associated with desirable traits in mutants of an elite rice cultivar. MutMap combines a strategy of cross-breeding a mutant plant with a desirable trait back to its wild-type parent with whole-genome sequencing of a sample of bulked DNA from several of the resulting crossbreeds. The method's simplicity and efficiency relative to previous methods could help accelerate the improvement of rice and other crops through genomic marker-assisted selective breeding, the group reported. Ryohei Terauchi, the team's leader, told In Sequence that marker-assisted selection has become more and more widespread in crop breeding, but it remains challenging to locate markers for agronomically important traits like yield, flowering time, plant height, and biomass. 
From today's paper: Hardier and more productive strains of rice are being developed faster than ever.
Today, around 3.5 billion people will sit down to a meal of something and rice. The “something” will depend on whether it’s Jamaica, Shanghai or Kerala, but rice is one of the world’s constants. It is a staple food for nearly half the globe and provides a fifth of all the calories humanity consumes. It is hard to overstate its importance. And that importance is growing: the world’s population, which swept past seven billion last year, is projected to reach nine billion by 2050. How are we going to feed all those new mouths? 
Japan is still struggling to recover from the devastation caused by the Tōhoku earthquake and tsunami that hit the country last March. One of the long-term problems is reclaiming farmland ravaged by the tsunami. 
Scientists in Britain and Japan have unveiled a fast-track way towards breeding crops with higher yields or resistance to climate change. 
Späte folgen bringt der Tsunami des letzten Jahres für die japanischen Reisbauern mit sich: Das Salz des Meereswassers lässt die Pflanzen nicht mehr richtig wachsen. Wissenschaftler haben nun eine neue Methode präsentiert, die rascher zu salzresistenten Sorten führen könnte. 
Meriveden suolaamilla riisipelloilla Japanin tsunamialueella kasvanee piakkoin suolaa sietäviä riisilajikkeita. Japanilais-brittiläinen tutkimusryhmä on kehittänyt jalostusmenetelmän, jolla kasveista voidaan eristää haluttu ominaisuus – vaikkapa suolankestävyys – huomattavasti aiempaa nopeammin. Sono state ottenute piante di riso resistenti al sale e adatte alle risaie giapponesi che lo tsunami del marzo 2011 ha inondato di acqua e fanghi salati, rendendole inadatte alla coltivazione. Il risultato, descritto su Nature Biotechnology, si deve a un gruppo di ricerca giapponese e britannico dell'Iwate Biotechnology Research Centre. Le piante sono state ottenute grazie a un nuovo metodo chiamato Mut Map, che permette di ottenere le piante con le caratteristiche desiderate in modo piu' veloce. 
Los investigadores han desarrollado un método, MutMap, para seleccionar semillas de alto rendimiento en un tiempo récord. Aumentan las mutaciones genéticas y sólo requieren una sola unión para aislar las nuevas variedades. |
With advances in a technique known as fast-track breeding, researchers are developing crops that can produce more and healthier food and can adapt and thrive as the climate shifts. 
Scientists merge traditional crop breeding with modern genomics to make a new salt-resistant rice plant. 
Scientists are developing a salt-resistant variety of rice. The move was prompted, in part, by last year's Japan tsunami, which flooded some 20,000 hectares of rice paddies. 
Ni OGM, ni processus classique de sélection par croisements successifs: des chercheurs ont dévoilé dimanche une technique révolutionnaire pour produire en un temps record des semences à fort rendement ou résistantes au changement climatique. 
A method for marker-assisted breeding, conceived in 2009 through a collaborative research project between the UK and Japan, is now focused on developing rice breeds tolerant to salt-sodden Japanese soils following the Tsunami last year. 
Des chercheurs ont développé une méthode, MutMap, permettant de sélectionner des semences à forts rendements en un temps record. Ils dopent les mutations génétiques et n’ont besoin que d’un seul croisement pour isoler les nouvelles variétés. A tavalyi japán földrengés, illetve az azt követő szökőár nemcsak a városi infrastruktúrát, hanem a mezőgazdasági területeket is károsította. A helyzetet tovább súlyosbítja, hogy Japánban a termőterület mérete alacsony, a szökőár által elmosott szántóföldeketet viszont a sós tengervíz megművelhetetlenné tette. Az ehhez hasonló mezőgazdasági katasztrófák után a termőtalajnak körülbelül tíz évre van szüksége a regenerálódáshoz, a gazdáknak pedig olyan haszonnövényekkel kell kísérletezniük, amelyek sós talajban is képesek növekedni. 
The majority of agronomic traits are controlled by multiple genes that cause minor phenotypic effects, making the identification of these genes difficult. Here we introduce MutMap, a method based on whole-genome resequencing of pooled DNA from a segregating population of plants that show a useful phenotype. In MutMap, a mutant is crossed directly to the original wild-type line and then selfed, allowing unequivocal segregation in second filial generation (F2) progeny of subtle phenotypic differences. This approach is particularly amenable to crop species because it minimizes the number of genetic crosses (n = 1 or 0) and mutant F2 progeny that are required. We applied MutMap to seven mutants of a Japanese elite rice cultivar and identified the unique genomic positions most probable to harbor mutations causing pale green leaves and semidwarfism, an agronomically relevant trait. These results show that MutMap can accelerate the genetic improvement of rice and other crop plants. |
