Taro DNA mapped by UHH scientists


By TOM CALLIS

Tribune-Herald staff writer

As any farmer knows, not all types of taro are created equal.

But with few genetic differences between the varieties grown in Hawaii — about 50 altogether — identifying each strain can be difficult for scientists.

Researchers at the University of Hawaii are working to change that by mapping the DNA for each variety.

That effort has been under way for about seven years, said Michael Shintaku, a plant pathologist with UH-Hilo. So far, they have learned the DNA footprint of less than half of the plants.

“We’ve tried pretty much all of the Hawaiian varieties,” Shintaku said.

“We’re not able to resolve them all. About a little more than half of the Hawaiian varieties are not resolvable.”

Those that have not been fully mapped are lumped into groups of two to eight different varieties.

To get better results, researchers are using different techniques, Shintaku said.

By gaining the DNA footprints, scientists can better understand the traits of each, which can help them find better matches for cross breeding.

Cross breeding helps develop more resistant varieties to disease, such as leaf blight, without having to result to genetic engineering.

“If you can show a variety is resistant to taro leaf blight, a DNA test will help you out that way,” Shintaku said.

The university has focused on cross breeding taro after a genetically modified plant it produced prompted a public push back about a decade ago.

The GMO taro used a wheat gene to make it resistant to leaf blight, a disease that can damage or destroy the plant.

But the university has since operated under a moratorium of such genetically engineered taro, Shintaku said, due to strong opposition, primarily among Native Hawaiians who revere taro much like an ancestor.

Much of the current research is done at UH’s agriculture research center outside Hilo.

One of the main researchers, Susan Miyasaka, an agronomist with UH Manoa, said the goal is to make plants that are resistant to diseases like leaf blight but also commercially viable.

“Basically, we’re trying to find varieties good for making poi,” she said.

One cross-bred variety that’s resistant to leaf blight has been introduced to farmers in Kauai, Miyasaka said.

How many farmers have accepted it was unclear, but she estimated use at about 25 percent. Multiple calls to the Kauai Taro Growers Association were not returned.

Miyasaka said researchers are working with a grant that will expire next year. Other funding sources are being pursued, she said.

Jerry Konanui of Pahoa said the university made the right choice by putting a moratorium on GMO taro.

Konanui is an expert on Hawaiian taro and assists scientists with their research. He also works with farmers around the state to identify the many taro varieties.

“They (were) chasing a dream, chasing a super taro,” he said. “And this is all myth.

“When you use original (strains) you have less disease, better quality, better everything.”

Email Tom Callis at tcallis@hawaiitribune-herald.com.

 

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