Showing posts with label Rice. Show all posts
Salt-Tolerant Rice 'Could Aid Japan's Tsunami Farmers'
Posted by Unknown in Flood, Food Security, Japan, Plant Breeding, Research and Technology, Rice, United Kingdom (UK) on Tuesday, 29 January 2013
UK
scientists have claimed a breakthrough in research on rice that could
help farmers devastated by last year's tsunami in Japan.
Researchers
in Norwich said a method of identifying and isolating crop traits has
been developed that means new varieties could be created in a year.
A Sainsbury Laboratory scientist said Japanese farmers could now grow a salt-resistant crop within two years.
It previously took up to 10 years to develop new crop strains, he said.
Much
of the agricultural land to the north east of Japan was drenched in sea
salt from the tsunami, which has since made it hard for rice to grow.
As
part of the research between the UK and Japan, a spokeswoman from the
Sainsbury Laboratory said seven salt-tolerant mutants have now been
identified in a particular type of rice, meaning breeders could be
creating usable varieties for Japanese farmers in the next few years.
"This is a huge leap forward," said Dr Brande Wulff from the Sainsbury Laboratory at Norwich Research Park.
Crop traits
"Advances in technology allow us to sequence plant genomes and identify gene variants that give rise to desirable traits.
"Our colleagues in Japan have already identified mutants that are more salt-resistant.
"Now
it's just a matter for them to back-cross those mutants to the parental
variety and clean up the background - get rid of the bad mutations and
keep the good one - and then bulk up the seed provided to the farmers,"
he said.
Crop
traits such as drought and salt tolerance, plant height and yield are
often controlled by many genes, with each having a subtle effect, the
laboratory spokesman said.
It is therefore difficult to identify the complete genetic basis for a particular characteristic, he added.
But
in the new research method, called MutMap, the laboratory said
scientists can now identify the characteristics by working with an
"elite" rice and creating mutants that harbour different traits.
'Genomics revolution'
Once
a mutant is identified with the desired trait, for example salt
tolerance, this can then be crossed with the original rice and grown in a
field.
The difference between the offspring of this cross and the elite rice can then be identified.
The
changes detected are called single-nucleotide polymorphisms (SNPS) and
insertion-deletions (indels), which are tiny genetic improvements that
can be observed using genome sequencing.
"Until
now, plant breeding has not been able to take advantage of the genomics
revolution," said Professor Ryohei Terauchi, from Japan's Iwate
Biotechnology Research Centre.
"MutMap
overcomes one of the greatest limitations, which has been the time it
takes to identify genetic markers for desirable traits."
Results from the study have been published in Nature Biotechnology.
Researchers Aim to Flick The High-Carbon Switch on Rice
Posted by Unknown in Genetics, Research and Studies, Rice on Monday, 28 January 2013
'C4 photosynthesis', as used by maize and sorghum, could greatly boost rice yields, after a decade of slowing improvements.
Codename: C4
rice project. Mission: to modify photosynthesis in rice to boost crop
yields. Duration: 15 to 25 years. This might sound like science fiction,
but it is already under way at the International Rice Research
Institute (IRRI) in
the Philippines, where William Paul Quick and his team have been working
since 2008 on changing the photosynthesis process in rice from the C3
carbon-fixation mechanism, common to 98% of all plants, to its much more
efficient C4 counterpart.
Some 50
species, including maize and sorghum, have completed this step
naturally, enabling the plants to devote most of their energy to
carbon-fixing, and thus to growth. "At present we are studying how far
the cell structures and enzymes required to achieve C4-type
photosynthesis are already present in rice and closely related plants,"
says Nourollah Ahmadi, a rice specialist at France's Centre for International Co-operation on Farming Research for Development. "The
aim is to activate the available but as yet inactive cell structures
and enzymes and to introduce the ones that are lacking by genetic
transformation, drawing on other plants."
This could
increase output by as much as 50%, bringing about another green
revolution, capable of responding to the foreseeable demand for food in
2050, when there will be 9 billion mouths to feed. Rice is currently the
staple foodstuff for more half the world's population, with more than 1
billion people depending on rice farming for their livelihoods. "For
every additional billion people, an extra 100m tonnes of rice will need
to be produced," says Ahmadi. In contrast, the annual increase in yields
has slowed since the 1990s, from 2% to just 1%.
Research into
rice now concentrates on creating varieties that are more productive and
more resistant to the various forms of stress, caused by disease (such
as pyriculiariosis) or environmental factors (flooding, drought, extreme
temperatures and high salt concentrations).
"Rice will be
one of the cereals most affected by climate change," says Robert
Zeigler, the head of IRRI. "So it's vital to prepare production systems
and rice growers for change if we want to maintain a certain dynamic."
Hopes are consequently high for the programme launched by IRRI and China
to sequence the genome of 10,000 of the 120,000 known rice varieties.
The first results are due in June.
"Thanks to new
sequencing techniques, we can determine the specific features of the
genome of any particular variety," says Mathieu Lorieux, a geneticist at
France's Development Research Institute (IRD). "Our work then consists
in cross-breeding the most useful species to obtain new ones that meet
consumer demands and environmental constraints, and are resistant to
disease."
Lorieux is
taking part in a programme to overcome the sterility barrier between
Asian (Oryza sativa) and African rice (Oryza glaberrima), the idea being
to develop hybrid varieties combining the former's productivity with
the robustness of the latter. He is also working on the plant's
architecture, so that each shoot produces more grain.
In 2011 IRRI launched a four-year programme on the Mekong delta, in Vietnam, to add flood and salt-tolerant genes to rice.
"More or less
all over the world, the potential yield from rice is about 10 tonnes a
hectare, whereas the global average is only 4.5 tonnes," Ahmadi
explains. "But the effort required to bridge this gap is increasing all
the time."
No transgenic
rice varieties are currently being cultivated, but "golden rice", a
variety developed a decade ago to have added vitamin-A, did cause
controversy. Lorieux is certain we shall one day eat transgenic rice:
"If a new disease appears and there are no resistant rice varieties, we
shall have to look for a resistant gene elsewhere or maybe make a
synthetic gene ... or give up growing rice."
This article originally appeared in Le MondeGilles van KoteGuardian Weekly
