“The Green Revolution has an entirely different meaning to most people in the affluent nations of the privileged world than to those in the developing nations of the forgotten world”.
- Norman Borlaug
RICE is life for most people living in Asia. Rice has changed the culture, diets, and economies of hundreds of millions of people. Its importance can be seen in the United Nations’ declaring the year 2004 as the “International year of rice,” and the United Nations General Assembly reaffirmed the need to focus world attention on the role rice can play in providing food security and eradicating poverty. The Green Revolution, which occurred in the late 1960s, was a turning point in Indian agriculture. There was remarkable growth in agriculture during the Green Revolution and this sector has been successful in keeping pace with growing demand for food grains in the world. However, though rice production growth trend had kept pace with population growth rate in the last five decades, signs of decreasing growth rate are evident. Currently, world rice production is passing through serious constraints such as plateauing of yield, water scarcity, increased use of agro inputs, irregular monsoons, increasing soil mineral stress, flash floods, water logging, labour scarcity, inadequate storage facilities, invasive pests and diseases, lack of policy innovations, and inadequate institutional dynamics. These have been a cause of concern. During the Green Revolution period, the semidwarf, fertilizer-responsive, high-yielding genotypes of rice and wheat were introduced, which led to phenomenal increase in production and productivity of these crops. It appears that the technology introduced during that time has reached a phase of diminishing returns. Hence, it is very pertinent to critically consider whether rice production can be further increased to keep pace with population growth through current green revolution technologies. There is a need for a paradigm shift in rice research to meet the challenges of the future decades for ensuring food security. We need to adopt the gene revolution technologies.
Several alternative approaches need to be explored to meet future challenges in terms of enhancing genetic yield potential, increasing resource-use efficiency, tolerance of biotic and abiotic stresses, and improving the nutritional quality of the rice grain. The potential of hybrid rice technology to enhance productivity and production of rice has to be fully utilized. Some of the major constraints to the further expansion of hybrid rice are lack of matching grain quality, lack of resistance to major pests and diseases, and higher seed cost. Research efforts to overcome these constraints have to be done. It is expected that hybrid rice will play a major role, along with the New Plant Type (NPT) varieties, in raising the productivity and production of rice in the coming decades. Water stress is an important abiotic stress limiting rice yields across the world. Traditionally, the rice crop requires almost thrice the quantity of water when compared to maize and wheat. The progressive reduction in water resources across the world necessitates the development of alternative strategies to combat water stress in rice. One such strategy is the development of “aerobic rice,” which can survive without constant flooding. Biotechnology can help in the development of aerobic rice through the application of molecular markers, genetic engineering, and genomic tools. Novel molecular and biotechnological methodologies can be used to identify stress-related genes and use them as probes for selection of tolerant genotypes and for generation of transgenic plants. Similarly, identification and utilization of molecular markers linked to gene(s) associated with drought tolerance can tremendously boost the capacity of rice cultivars to resist water scarcity.
The efforts of rice breeders have no doubt brought the rice yield levels to such a stage where, at least for the present, food production growth will possibly outrace population growth. But, we should not be complacent as the vagaries of monsoons and disturbing trend with respect to soil health are bound to destabilize rice production. We must therefore be ready to face the challenges of the future by judicious and prudent application of biotechnological tools. The application of molecular markers in rice improvement started with the efforts of Cornell University and IRRI using RFLP markers for developing molecular linkage maps in rice. More than 25 agronomically important rice genes have already been tagged with markers and can readily be deployed by breeders in breeding programs. Genetic transformation is another tool that promises to revolutionize the Indian rice production scenario. The most important advantage of transgenic technology is its capacity to mobilize useful genes from non-rice gene pool to rice with the least disruption to the rice genome. Genetic engineering can be used for developing rice cultivars with enhanced abiotic stress tolerance and nutritional quality. Transgenic technology can also be employed to attempt to convert rice from being a C3 to a C4 plant. It is hoped that through this, the photosynthetic efficiency and, consequently, the yield, can be increased tremendously. Similar to DNA marker technology and rice transgenics, rice genomics is another area full of prospects.
In view of the growing demands due to the ever-increasing population, it is imperative that rice production and productivity need to be enhanced through application of modern tools of science. It is also equally important to make rice cultivation more profitable and less labour-dependent. Paradigm shift is needed in the way we grow rice in the backdrop of declining resources, escalating labour cost, and deteriorating soil health. ‘Grow more with less inputs’ would be the way forward for sustainable rice production in the coming decades.
Note: The views and opinions on this essay are those of the author's and do not reflect those of the institute and its partners.
Jyothsna Naidu is an agriculture graduate who completed her Master's degree in plant breeding and genetics from Tamil Nadu Agriculture University, India. She also worked as a Mandal Agriculture officer in the state government of Andhrapradesh.