Innovate

BE THE LINCHPIN OF SCIENTIFIC INNOVATION AND THOUGHT LEADERSHIP SOLVING COMPLEX PROBLEMS WITH DEEP RESEARCH

As it works toward building a smarter and sustainable rice sector, IRRI draws on the strength of its innovation edge for new ideas that will address upcoming challenges in crop production and productivity. In 2018, IRRI partnered with government and private organizations in its relentless pursuit of innovations that benefit farmers and push the limits of rice science into new disruptive territories. These are some of the groundbreaking explorations centered on bringing the newest technology into the farmer’s field.

Bacterial blight is a major rice disease that severely affects rice production in Asia. In irrigated environments, bacterial blight can easily spread to large areas causing up to 30% in losses and a huge impact on the income of smallholder farmers.

Major genes called Xa genes (e.g., Xa4, Xa5, Xa21), have already been used in rice breeding programs for developing varieties that have some resistance to the disease. However, despite the importance of these genes in controlling the disease, the bacterium adapted to these resistant varieties making them susceptible again. There is a need to continue discovering new ways and developing varieties that can protect farmers from losses caused by bacterial blight.

In a recent paper published in PLOS One, scientists discovered variations of the SWEET (sugars will eventually be exported transporter) genes that give plants resistance to Xanthomonas oryzae pv. Oryzae, the organism that causes bacterial blight.

Under normal conditions, the pathogen promotes the leakage of sugars by activating the SWEET genes inside the plant cell. However, the new SWEET gene variants prevent the release of sugar and the bacterium fails to get nutrition from the host plant and it eventually dies. The gene naturally occurs in rice and offers a promising strategy to gain resistance against bacterial blight.

“Using IRRI’s rich germplasm collection, we were able to discover the potential of variations in the SWEET gene to be used in breeding new blight-resistant varieties,” said Dr. Ricardo Oliva, a plant pathologist at the institute. “The variations appear to have emerged from at least three rice subspecies. This opens up the gates to use similar techniques to fight other pathogens in rice as well as in other crops such as corn, wheat, and cassava.”

At present, the SWEET gene variants have been introduced into IRRI’s breeding pipeline and a new class of rice varieties resistant to bacterial blight will be available in a few years.

“This year, we were able to develop new populations and parental lines for breeding, new hybrids for testing, and new DNA markers for forward breeding,” Jauhar Ali, coordinator of the Hybrid Rice Development Consortium (HRDC), reported at the 2018 HRDC annual meeting. “These advances generated more resources and opportunities that enabled HRDC members to develop high-performing varieties.”

Dr. Ali also reported the licensing of two hybrid rice varieties (Mestiso 61 and Mestiso 68) to SL Agritech Corporation under the limited exclusivity agreement. Mestiso 30, another new hybrid rice variety was provided to Advanta Seeds under a non-exclusivity license agreement.

Collaborations between IRRI and private partners in hybrid rice research and development significantly accelerate and broaden the distribution and delivery of improved seeds to farmers globally. “These agreements are expected to generate benefits not just for HRDC but, more importantly, for the smallholder farmers who will use the developed hybrid rice varieties,” said Dr. Ali.

One of the highlights of the two-day meeting is a series of discussions led by IRRI scientists on using bacterial genomics for effective pathogen monitoring in rice, the potential of direct-seeded rice hybrids in maximizing productivity and environmental sustainability in Asia, and the impacts of hybrid rice in the yield and income of smallholder farmers.