Manila, The Philippines
August 26, 2008
by Angelina Garces, S&T Media
Service
After the public sector biotechnology initiatives on the papaya
ringspot virus-resistant variety, the government is now focusing
on improving corn.
In this regard,
PCARRD (the Philippine Council for Agriculture, Forestry and
Natural Resources Research and Development) approved recently a
three-year project in the amount of P8.6 million. Titled
"Molecular map-based isolation and characterization of
resistance genes for downy mildew (DM) in corn," the project
aims to develop corn varieties resistant to DM using
marker-assisted
selection (MAS).
DM, caused by Peronosclerospora philippinensis Weston (Shaw), is
still one of the major corn diseases in the country despite
earlier breakthroughs in chemical control. High incidence of DM
has been observed in Northern Luzon and many parts of Mindanao,
particularly when seeds are not treated with fungicides. In
severe infections, yield loss due to the disease was reported to
be as high as 80-100%.
For the past decades, the Institute of Plant Breeding of the
University of the Philippines Los Baños (IPB-UPLB) has been
incorporating downy mildew resistance in its corn breeding
program using conventional approaches. Several resistant
varieties have been released but through time, they succumbed to
the disease.
Unlike conventional selection wherein plants are allowed to grow
to maturity to determine their desirable traits, MAS uses
genetic markers to do the same thing much faster.
Deoxyribonucleic acid or DNA markers have been linked and
identified with the DM-resistance gene. The use of these markers
to select the desired plants that carry the DM resistance genes
has also been well established in corn and other major crops
like rice and wheat.
Incidentally, the project will use markers in selecting corn
lines that carry the resistance gene. Such procedure will make
the development of DM-resistant corn variety a lot faster. The
DM-resistant corn varieties will then be tested in several
locations of the country targeting the major corn-growing areas.
In the absence of DM-resistant variety, corn farmers are forced
to treat seeds with fungicide, which is a potential contaminant
of ground water and suspected to cause cancer. Availability of
DM-resistant corn variety will, therefore, benefit the farmers
in terms of higher yield and income, and better health.
A leading public sector institution, UPLB's College of
Agriculture, its Crops Science Cluster, and IPB will implement
the project, under the leadership of Dr. Hayde F. Galvez. |
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