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A NEW
rice variety, developed by a leading rice-research
agency in Asia, for flooded, low-lying fields promises
not only of enduring flood water but also of resisting
the three known most dreaded rice pests—bacterial blast,
tungro and stemborer.
The
scientists involved in breeding the new Tubigan 7 rice
variety used the DNA marker-aided selection (MAS)
technique in identifying the genes for each desired
traits of submergence tolerance and resistance to pests.
“Instead
of the usual laboratory tests, the breeders took pains
in identifying the genes to come out with the target
characteristics of the variety,” said Dr. Antonio
Alfonso, head of plant breeding and biotechnology
division of the Philippine Rice Research Institute (PhilRice)
in Muñoz Science City in Nueva Ecija, which initiated
the development of Tubigan 7.
Alfonso
emphasized, however, that Tubigan 7 is not a genetically
modified rice. “These [genes involved] are not
transgenic. Source of genes were still rice and [the
method was] made through conventional breeding,” he
said.
Tubigan
7, which means “flooded,” in the vernacular, is an elite
line with IR64 background. It also has fertility
restorer trait and could yield about 8 tons per hectare
during the dry season cropping and 5 to 6 tons per
hectare during the wet season, 15 percent higher than
the conventional harvest record in the Philippines.
PhilRice
said Tubigan 7 is “the first-ever successful DNA-MAS
product in the Philippine rice breeding.”
This is
also the second locally developed biotechnology rice,
the first being the tissue culture-derived variety of
improved traditional wagwag, Antonio said.
PhilRice
completed the Tubigan 7 breeding process in June 2006
after nearly a decade of testing series, and recently
the Philippine National Seed Industry Council (NSIC)
officially released it as a variety.
The
scientists involved in the project—Rolando Tabien,
Marilou Abalos, Maricar Fernando, Emily Corpuz, Yolanda
Dimaano, Gloria Osoteo, Rolando San Gabriel, Dindo
Tabanan, Herminia Rapusas, Juliet Rillon and Leocadio
Sebastian—cross-combined 103 genes with BB-, tungro-,
and stemborer-resistance traits, as well as earliness
genes during the dry season.
After
they made additional crosses during the wet season—14 of
them were for tungro-resistance and five for
BB-resistance.
Alfonso
explained that to come out with the flood-tolerant gene,
the scientists applied the DNA-MAS crop breeding
technique, which is direct extraction of DNA from each
plant in the test field to determine which of the plant
is resistant and which is susceptible to bacterial
blight instead of the usual laboratory test. |