This will squeeze a significant gain in yield for corn likely on the
range of perhaps another twenty percent. Corn is been subjected to
many other beneficial improvements that secures it position as the
leading field crop. In time we will have a rich nutrient enhanced
product that is welcome everywhere.
The conversion to corn culture worldwide continues to be rewarding
and well rewarded and is handily providing us much of our food
security. It will clearly continue to expand its range.
It is all good news for the long term as agriculture prepares to
shift into organic methods.
Plant scientists at
CSHL demonstrate new means of boosting maize yields
by Staff Writers
Cold Spring Harbor NY (SPX) Feb 12, 2013
A team of plant
geneticists at Cold Spring Harbor Laboratory (CSHL) has successfully
demonstrated what it describes as a "simple hypothesis" for
making significant increases in yields for the maize plant.
Called corn by most
people in North America, modern variants of the Zea mays plant are
among the indispensable food crops that feed billions of the planet's
people. As global population soars beyond 6 billion and heads for an
estimated 8 to 9 billion by mid-century, efforts to boost yields of
essential food crops takes on ever greater potential significance.
The new findings
obtained by CSHL Professor David Jackson and colleagues, published
online in Nature Genetics, represent the culmination of over a decade
of research and creative thinking on how to perform genetic
manipulations in maize that will have the effect of increasing the
number of its seeds - which most of us call kernels.
Plant growth and
development depend on structures called meristems - reservoirs in
plants that consist of the plant version of stem cells. When prompted
by genetic signals, cells in the meristem develop into the plant's
organs - leaves and flowers, for instance. Jackson's team has taken
an interest in how quantitative variation in the pathways that
regulate plant stem cells contribute to a plant's growth and yield.
"Our simple
hypothesis was that an increase in the size of the inflorescence
meristem - the stem-cell reservoir that gives rise to flowers and
ultimately, after pollination, seeds - will provide more physical
space for the development of the structures that mature into
kernels."
Dr. Peter Bommert, a
former postdoctoral fellow in the Jackson lab, performed an
analytical technique on several maize variants that revealed what
scientists call quantitative trait loci (QTLs): places along the
chromosomes that "map" to specific complex traits such as
yield. The analysis pointed to a gene that Jackson has been
interested in since 2001, when he was first to clone it: a maize gene
called FASCIATED EAR2 (FEA2).
Not long after cloning
the gene, Jackson had a group of gifted Long Island high school
students, part of a program called Partners for the Future, perform
an analysis of literally thousands of maize ears. Their task was to
meticulously count the number of rows of kernels on each ear. It was
part of a research project that won the youths honors in the Intel
Science competition. Jackson, meantime, gained important data that
now has come to full fruition.
The lab's current
research has now shown that by producing a weaker-than-normal version
of the FEA2 gene - one whose protein is mutated but still partly
functional -- it is possible, as Jackson postulated, to increase
meristem size, and in so doing, get a maize plant to produce ears
with more rows and more kernels.
How many more? In two
different crops of maize variants that the Jackson team grew in two
locations with weakened versions of FEA2, the average ear had 18 to
20 rows and up to 289 kernels - as compared with wild-type versions
of the same varieties, with 14 to 16 rows and 256 kernels. Compared
with the latter figure, the successful FEA2 mutants had a kernel
yield increase of some 13%.
"We were excited
to note this increase was accomplished without reducing the length of
the ears or causing fasciation - a deformation that tends to flatten
the ears," Jackson says. Both of those characteristics, which
can sharply lower yield, are prominent when FEA2 is completely
missing, as the team's experiments also demonstrated.
Teosinte, the humble
wild weed that Mesoamericans began to modify about 7000 years ago,
beginning a process that resulted in the domestication of maize,
makes only 2 rows of kernels; elite modern varieties of the plant can
produce as many as 20.
A next step in the
research is to cross-breed the "weak" FEA2 gene variant, or
allele, associated with higher kernel yield with the best maize lines
used in today's food crops to ask if it will produce a higher-yield
plant.
"Quantitative
variation in maize kernel row number is controlled by the FASCIATED
EAR2 locus" appears online in Nature Genetics on February 3,
2013. The authors are: Peter Bommert, Namiko Satoh Nagasawa and David
Jackson. The paper can be viewed here
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