Special Features Agriculture Breeders walk the wild side of rice
Breeders walk the wild side of rice
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- Published on Friday, 01 June 2012 00:00
- Written by MA. LIZBETH BAROñA
By A Web design Company
Scientists are scouring the deep and “wild” end of the rice gene pool to help find hidden traits and genes that can help breed new varieties better at thriving and producing food in difficult environments.
Although the genetic diversity of cultivated rice is already rich, widening its diversity through its wild relatives is significant, as they possess high-value traits that can help breeders make new varieties that can stand up to climate change and other challenges.
Rice has wild or undomesticated relatives, called “wild rice,” that are rich repositories of genetic material that can provide tolerance of environmental stresses and help improve yield.
Wild rice diversity is considered to be in the periphery of the rice gene pool, with the center being around varieties cultivated from the two main species of rice: Oryza sativa and O. glaberrima; there are 27 species of rice.
Wild rice’s richness in desirable traits, such as pest and disease resistance, is borne out of centuries of surviving in harsh environments – untended and away from human intervention. These important traits have been infused in cultivated varieties to help protect them against pests and asdiseases that have affected thousands of hectares of rice farms and have caused millions of dollars of damage.
The International Rice Research Institute (IRRI) and its partners carry out rice improvement activities using wild rice traits. By way of conventional breeding and modern biotechnological tools, these crucial traits are transferred to cultivated varieties and have resulted in rice varieties with improved resistance to bacterial blight, blast, tungro, brown planthopper and soil toxicity.
To name a few species, wild rice O. minuta gave breeders genes that contain resistance to bacterial blight, blast, brown planthopper and sheath blight. Resistance to tungro virus, on the other hand, was found in wild rice O. rufipogon.
The opportunities are expanding as more is learned about how to explore the diversity in wild rice to improve cultivated rice.
“We have now succeeded in transferring genes from almost every species in Oryza, giving access to the full range of genetic diversity in the genus,” said Dr. Kshirod Jena, head of interspecific hybridization breeding at IRRI.
Genetic diversity is the foundation of the genetic improvement of crops. IRRI seeks to understand rice genetic diversity and uncover new genes and traits in rice that will help breeders face challenges brought about by climate change, pests and diseases, and other unfavorable conditions.
“Our latest important result is the transfer of a gene with resistance to the brown planthopper,” said Jena. The gene was transferred from the wild rice O. australiensis to a high-yielding variety for cultivation in South Korea.
This variety is called Anmi. This is a significant achievement because host-plant resistance is an effective way to control brown planthopper, a pest that has rendered hundreds of millions of dollars in damage across Asia.
“From the same wild rice, O. australiensis, we have identified a blast-resistance gene that will soon be infused in cultivated varieties,” Jena explained.
“Perhaps the brightest prospect from wild rice is that we at IRRI are in the process of transferring yield-enhancing genes from O. rufipogon. In the future, we will develop new varieties that are not only resistant to pests and diseases, but that are also able to give better yield.”
