UPLB seeks white corn varieties resistant to Fusarium ear rot

MANILA, Philippines - At least 12 local white corn varieties have initially been found to be resistant to Fusarium ear rot, a study conducted by the University of the Philippines Los Baños (UPLB) showed.

Researchers at the UPLB have been screening 43 white corn lines, among which, three have been found to have very strong resistance traits.

These resistant lines, which would still be subjected to confirmatory tests, may be used in developing more resistant varieties.

Fusarium ear rot is a corn disease prevalent in tropical and subtropical regions. Data from the UPLB-Institute of Plant Breeding indicate that during the 2007 wet season, 35 percent of corn ears harvested was infected with the pathogen.

White corn is consumed in the Philippines as a staple along with rice.

Fusarium ear rot may not immediately manifest in standing crops. As such, infected corn may enter the food supply chain.

The DA biotechnology program office said some species of the pathogen produce fumonisin, a family of mycotoxins, that can cause serious animal and human diseases, including esophageal cancer and neural tube birth defects in humans and lethal horse disease and porcine pulmonary edema in animals.

The most predominant fumonisin-producing Fusarium species causing Fusarium ear rot in the Philippines is F. verticillioides, F. proliferatum and F. graminearum.

Preliminary results of the study based on the physical traits and genetic diversity of the ear rot pathogen suggest that it is highly diverse and able to adapt under local conditions, suggesting a high possibility of the rapid evolution of resistance against the current control measures such as application of fungicides.

Increased humidity, hot weather and drought conditions aslo favor the proliferation of Fusarium.

The DA Biotech Program supports research initiatives that utilize biotechnological tools and generate beneficial technologies and novel information to help enhance genetic improvement of agricultural commodities and their production.