Misconceptions persist about GE Chinese taro

GATHERING PLACE
Susan C. Miyasaka

A BILL that has passed the Senate (SB 958) and one now in the House (HB 704, which passed out of the Agriculture Committee last week) would place a 10-year moratorium on testing, propagating, cultivating, raising and growing genetically modified taro. These bills are based on the fear that genetic engineering will contaminate the genetic identity of Hawaiian taro. I would like to correct some common misconceptions about the genetic engineering of taro:

» First, the taro varieties patented by the University of Hawaii are not GE varieties. They were conventional crosses resulting from hand-pollination of a Hawaiian variety with a Palauan variety.

» Second, no attempt was made to insert foreign genes into any Hawaiian taro variety.

» Third, the only taro variety that we genetically engineered is Chinese taro Bun long. We have inserted several disease resistance genes -- from rice, wheat and grape -- into this Chinese taro variety. In preliminary tests, one line of GE Chinese taro appears promising because it completely stopped the spread of the leaf blight in tissue-culture.

» Fourth, GE Chinese taro lines have been tested only in the laboratory. To find out whether this promising GE Chinese line really is resistant to leaf blight, testing in small, contained field conditions is necessary. Under small, contained field trials, accidental movement of foreign genes from GE Chinese taro to non-GE taro varieties is easily avoided by careful surveillance for and removal of flowers.

Let us look at the scientific facts about taro. Taro is a crop that is grown for either its leaf or its starchy corm (underground stem). Chinese taro Bun long rarely flowers under the environmental conditions of Hawaii. Unless Hawaiian taro varieties are hand-pollinated, they rarely produce seed capable of developing into whole plants. In order for foreign genes to move from a GE Chinese taro to a Hawaiian taro, the Chinese taro would need to flower (rare event), the pollen would need to move to a flowering Hawaiian taro (an infrequent event), seed would need to develop (rare event) and seedlings would need to germinate and grow into whole plants (rare event). What are the chances of this occurring? Extremely low.

There is a deadly viral complex in the South Pacific that would kill all Hawaiian taro varieties if it ever reached Hawaii. In the Solomon Islands, there is a "time of hungry" when sweet potatoes cannot be grown due to high rainfall, but taro cannot be grown either because it is killed by the viral complex. Genetic engineering for viral disease resistance saved the papaya industry in Hawaii. It has the potential to improve disease resistance in taro, too.

I believe that a win-win situation is possible. Modify the bills in the Senate and the House to place a 10-year moratorium on genetic engineering of Hawaiian taro only. Please let the members of my team continue their research to improve disease resistance on GE Chinese taro under the jurisdiction of university, state and federal guidelines. Let us work together to ensure that taro will be here for future generations to enjoy.

Susan C. Miyasaka is an agricultural scientist at the University of Hawaii-Manoa who has studied ways to improve taro yields, including testing of taro varieties conventionally bred for increased disease resistance, organic farming and genetic engineering of Chinese taro to increase its hardiness. She has never received funding from a multinational company that profits from GE crops. An update of her research results on GE Chinese taro can be downloaded from the following Web site of the College of Tropical Agriculture and Human Resources: www.ctahr.hawaii.edu/gmo/documents/Update-GE-Dec14-06.pdf, or mirrored here: Update-GE-Dec14-06.pdf.