Heat-tolerant rice varieties promises increased yields in Bangladesh

Date:07-04-2024

IRRI, in collaboration with BRRI and funded by BMZ, has developed heat-tolerant rice varieties to address the severe impact of rising temperatures on rice production in Bangladesh. 

Climate change, characterized by rising temperatures and increased frequency of extreme weather events, significantly impacts rice production and yields. High night temperatures disrupt the grain-filling process in rice plants, leading to reduced yields and lower grain quality. In Bangladesh, this results in substantial annual losses in rice production, threatening food security and farmer livelihoods. As temperatures continue to rise, the need for heat-tolerant rice varieties becomes increasingly critical to sustain rice production and mitigate the adverse effects of climate change.

Researchers at IRRI have identified genes responsible for improving rice yield in higher night (and day) temperatures and developed rice varieties that thrive in both high day and night temperatures. During the closing ceremony of the project titled "Heat Resilient Varieties with Reduced Impact of Combined High Day and High Night Temperatures on Rice Productivity with Added Premium Grain Quality for Improving Livelihoods in South and Southeast Asia" held in Dhaka, Bangladesh on 25 June, around 60 stakeholders gathered to share the project's results and findings.

The project, led by the International Rice Research Institute (IRRI) with Bangladesh Rice Research Institute (BRRI) as a key partner funded by BMZ (Federal Ministry for Economic Cooperation and Development), addressed the crucial issue of significant yield losses in rice production due to rising day and night temperatures by developing and testing heat-resilient rice varieties, the initiative aimed to mitigate the adverse effects of climate change, thereby enhancing food security and improving the livelihoods of smallholder farmers. The project employed advanced breeding techniques and participatory varietal selection to ensure the new rice varieties meet local agronomic and consumer preferences.

The evaluation of 16 heat-tolerant rice lines was conducted in various regions of Bangladesh, including Lalpur, Ghazipur, Dinajpur, Rajshahi, and Kushtia. The trials involved rigorous assessments of traits such as plant height, days to flowering, tiller numbers, fertility percentage, and yield under varying temperature conditions. Local stakeholders participated in the varietal selection trials, emphasizing the adaptability and performance of selected genotypes like IR18C1002, IR18C1004, and IR18C1005.

The BMZ Heat project conducted a comprehensive assessment of heat-tolerant rice lines in five different hotspots. The study showed that these rice lines were able to adapt to varying day and night temperatures, which ranged from 28˚C to 43˚C during the late Boro season trial in 2023, and 22˚C  to 32˚C in the late Aus season of 2023. This breakthrough not only demonstrated the resilience of specific high-temperature tolerant genotypes, such as IR154 and IR18C 1005, to high temperatures, but also emphasized the adaptability of selected genotypes, like IR18C IR1002 and IR18C IR1004, for stable performance and improved rice production in heat-tolerant regions.

IRRI, BRRI, local farmers, seed producers, and NARES breeders—all the stakeholders—worked together to ensure the varieties are well-adapted to our region's specific climatic challenges.

Dr. Nese Sreenivasulu, Research Unit Leader-Consumer-driven Grain Quality and Nutrition, and BMZ Heat Project Lead from IRRI, said, ″The trials have shown that the new rice lines can yield 1.5 to 2 tons more per hectare compared to traditional varieties, even under high night temperature conditions. These results were consistent over three years of testing, indicating the robustness of the heat-tolerant genes identified.″

Dr. Malay Choudhury, Additional Secretary, Extension Wing, Ministry of Agriculture, Bangladesh, and Chief Guest at the event, said during the closing ceremony of the project,  "I am sincerely grateful to everyone who is dedicated to addressing this issue. It is imperative for our country, as we have the potential to export products with our fertile soil. This project holds great promise for our nation, but it is essential to secure additional investment from the private sector and conduct further research."

Dr. Md. Shahjahan Kabir, Director General, of Bangladesh Rice Research Institute (BRRI) and chairperson of the event, said, "Bangladesh ranks 7th among the countries most affected by climate change. The impact is already significant and is expected to worsen over time, particularly affecting our agricultural output. Despite experiencing exceedingly high temperatures this year, we remain hopeful that with technological advancements and increased research, we can better prepare ourselves for these challenges."