Modernising rice breeding

In the face of mounting challenges like population growth, climate change, and shrinking arable land, Bangladesh must urgently reform its approach to rice production. As the backbone of the country's food security, rice constitutes 97 per cent of grain production and supplies over half of the nation's caloric and protein needs.

However, rice yields have reached a critical stagnation point, with genetic improvements contributing less than 1 per cent annual growth over the past five decades. To meet the projected demand of an additional 44.6 million tons of rice by 2050, modernising breeding strategies is no longer optional-it must become a national priority.

THE URGENCY OF FOOD SECURITY: Rice is more than just a staple food in Bangladesh-it is a lifeline for over 166.5 million people, with annual per capita consumption averaging 213.5 kilograms. With the population expected to surpass 215 million by 2050, the pressure on rice production will intensify. Without substantial improvements in productivity, Bangladesh risks facing crises akin to the 2007-08 rice shortages, which destabilised food systems and markets.

Despite advancements in mechanisation, irrigation, and fertilizer use, genetic gains in rice productivity have lagged far behind. Inbred varieties have shown annual gains of just 0.28 per cent in Boro and 0.18 per cent in Aman rice-figures insufficient to meet future food security demands. For policymakers, the question is not whether to modernise rice breeding, but how quickly and effectively this transformation can be realised.

BREAKING THE YIELD STAGNATION: Rice yield growth in Bangladesh has plateaued due to a persistent reliance on traditional breeding methods, primarily pedigree selection. While these techniques have historically been effective, they are no longer capable of overcoming the complex challenges of the modern agricultural landscape. Genetic improvements in yield have been marginal, with non-genetic factors like irrigation and inputs driving most productivity gains. To break this entrenched yield ceiling, Bangladesh must transition to science-driven, advanced breeding strategies.

A promising solution lies in recurrent selection, a method that enhances desirable traits by continuously selecting and interbreeding superior genotypes underpins continuous population improvement. When integrated with innovations such as genomic selection and rapid generation advancement (RGA), this approach can revolutionize rice breeding. Genomic selection, in particular, allows breeders to predict a plant's breeding value using its genetic data, enabling more precise selection and faster improvements of complex traits like yield. By accelerating the breeding cycle, this method can deliver high-performing varieties to farmers more quickly, significantly boosting productivity.

The Breeder's Equation, first introduced by J.L. Lush in 1937, remains a foundational concept for modern breeding strategies. It highlights the critical role of heritability and selection differential in driving genetic improvements, emphasising the careful selection and inter-mating of optimal parental lines to achieve maximum gains. In the current context, this approach is enhanced by pre-breeding techniques that focus on incorporating traits like climate resilience, disease resistance, and higher yields-essential for adapting to increasingly challenging environmental conditions.

LEVERAGING THE TRB APPROACH FOR SUSTAINED GAINS: To address yield stagnation, the International Rice Research Institute (IRRI) has launched the "Transforming Rice Breeding" (TRB) initiative, which integrates genomic selection, recurrent selection, and RGA to achieve consistent genetic gains in rice yield. Through the OneRice Breeding Strategy-a unified framework for rice breeding within the CGIAR system-Bangladesh has access to a global pool of genetic resources and cutting-edge innovations. This international collaboration offers an unprecedented opportunity to leverage breeding technologies that have been successful in other regions.

However, the effectiveness of these strategies depends on the commitment of national policymakers to invest in breeding infrastructure and long-term research. Without sustained funding and support, the potential of these advanced breeding methods cannot be fully realised.

OVERCOMING CHALLENGES AND CHARTING A PATH FORWARD: Despite the promise of modern breeding techniques, several challenges remain. A major concern is the potential loss of genetic diversity within breeding populations, a common outcome of recurrent selection. This narrowing of the gene pool could limit future opportunities for improvement, especially as climate change intensifies. To counter this, breeders must access global gene banks and incorporate elite exotic lines into their programs, maintaining the genetic diversity needed for long-term resilience.

Furthermore, expanding collaboration between the public and private sectors is crucial. Strong partnerships will ensure that farmers have access to high-quality seeds, advanced extension services, and market conditions that incentivize the adoption of high-yielding varieties. National breeding programs must also tap into global expertise, strengthening Bangladesh's position in the international research community.

Substantial investment is also needed in human capital and infrastructure. Breeders, researchers, and extension workers must be equipped with the latest tools and training to effectively implement these advanced techniques. To ensure progress, national policies should prioritize agricultural research and align with international best practices.

THE ROLE OF POLICY AND INVESTMENT: Unlocking the full potential of modern rice breeding requires a comprehensive policy framework that supports long-term innovation and research. This begins with increased funding for key institutions like the Bangladesh Rice Research Institute (BRRI) and IRRI, empowering them to drive continuous improvements in rice productivity.

Strengthening extension services is equally important to ensure that farmers can access new varieties and technologies. Extension workers must be trained to support farmers in adopting modern practices that enhance yield potential while minimizing environmental impacts. Additionally, ensuring profitable market prices for rice farmers will create the economic incentives necessary to drive widespread adoption of new, high-yielding varieties.

Policymakers must also take into account the looming impacts of climate change and shrinking arable land. Breeding programs must prioritise the development of climate-resilient rice varieties that can withstand extreme weather events such as droughts, heats and floods. Investing in sustainable rice production systems will be essential to safeguard food security in the face of increasingly unpredictable environmental conditions.

CONCLUSION: For Bangladesh, modernising rice breeding is not merely a choice-it is an urgent necessity. As the population grows and environmental challenges become more severe, the country must embrace innovative breeding strategies to secure its food future. By adopting cutting-edge technologies such as recurrent genomic selection, CRISPR-CAS, and bioinformatics, and committing to sustained investment in research and infrastructure, Bangladesh can break the yield ceiling and ensure food security for generations to come.

To achieve this, policymakers must prioritise the development of a national rice breeding policy, enhance extension services, and ensure that farmers have access to high-quality seeds and profitable markets. The stakes are high, but with the right strategies and investments, Bangladesh can maintain its position as a global rice producer and a model for food security in the 21st century.

Dr Md Kamal Hossain is a Senior Associate Scientist at the International Rice Research Institute's (IRRI) Bangladesh office in Dhaka. k.hossain@irri.org