The Philippine Rice Research Institute (PhilRice) has developed 25 new heat-tolerant varieties that can stand the impact of harsh climate change and other extreme weather conditions such as the El Nino phenomenon.
Dr. Norvie Manigbas, lead researcher, said the development of rice varieties with high temperature tolerance was intended to address effects of climate change in areas where 90 to 95 percent of the population depend on rice.
He said PhilRice was able to identify the new breeding lines after rigorous selection for high temperature tolerance using conventional method and marker-assisted selection.
“We established breeding nurseries in high temperature prone areas in Cagayan and Nueva Ecija to screen and select breeding materials under field conditions,” Manigbas said.
Rice grows optimally between 20-35°C and becomes increasingly sensitive to increasing temperatures especially during flowering. In 2010, Manigbas and his team developed new rice genotypes that can tolerate and adapt to high temperatures at 37-39°C under irrigated lowland conditions.
They identified N22 (Nagina 22 from India), Dular (India), and Nipponbare (Japan) as donor parents and used conventional breeding and molecular marker-assisted selection to generate new high temperature tolerant breeding populations.
Manigbas said planting was done on staggered basis so that flowering, or reproductive stage of all test entries, will coincide with the highest temperature during the growing season.
“PhilRice identified twenty five new breeding lines tolerant and 16 of those had lower percent sterility compared with the tolerant checks and donor parent N22,” he said.
Manigbas said the new lines will be evaluated further for other traits and if they passed, they can be nominated to the National Cooperative Test for Multi-Environment Testing.
With his co-researchers — Luvina Madrid, Corazon Cardenas, Evelyn Ladia, and Ferdinand Enriquez — Manigbas targets the promising line to be released as a new heat-tolerant rice variety in 2016-2017.
Their research won the bronze medal in the Gold AFMA Best R&D Paper Award.