Generación de líneas avanzadas de arroz (Oryza sativa L.) mediante mutagénesis para mejorar la eficiencia de uso del suelo y la productividad del cultivo

Rice is one of the most important crops in Central America, playing a key role in food security. In Costa Rica, this agricultural activity generates more than 15,000 jobs and represents a significant source of income for farmers in rural areas. However, the high costs of nitrogen fertilizers and their low field efficiency represent a major limitation for the profitability and sustainability of the sector. It is estimated that rice requires approximately 150 kg/ha of nitrogen fertilizer per cycle, equivalent to ₡350,000. This dependency has led to substantial economic and environmental vulnerability, given that up to 50 % of the applied nitrogen is lost through volatilization, leaching, and denitrification. This project proposes the development of mutant rice lines with tolerance to low nitrogen availability through radio-induced mutagenesis, a biotechnological technique that increases genetic variability and allows for the generation of materials with improved agronomic traits in a shorter time compared to conventional breeding. The research will be carried out at the Biotechnology Research Center and the Gamma Irradiation Laboratory, both of which have the infrastructure and specialized personnel required for these initiatives. The main objective is to increase genetic variability in rice and to select genotypes with greater nitrogen-use efficiency, thereby reducing dependence on synthetic fertilizers and associated costs. For this purpose, plant material will be established under in vitro conditions, and the median nitrogen inhibition concentration in the culture medium will be determined. Subsequently, mutations will be induced through gamma radiation exposure, followed by in vitro selection cycles under low-nitrogen conditions. Tolerant lines will be evaluated based on growth and survival indicators, and the most promising ones will be acclimatized and transferred to hydroponic systems for validation. The project is developed in close collaboration with the agricultural sector, addressing the identified need for rice varieties adapted to nutrient-poor soils. The resulting materials are expected to maintain the agronomic performance of commercial cultivars but with improved nitrogen-use efficiency, which could lead to a significant reduction in fertilizer use and an improvement in production profitability. The results of this research will strengthen breeding programs by promoting the local generation of materials adapted to the region agroecological conditions. Additionally, this initiative aligns with Sustainable Development Goal 2.4 and its indicator 2.4.1, which promotes sustainable, productive, and resilient agricultural systems. This project is innovative in integrating gamma radiation with in vitro culture as complementary tools for genetic improvement, enabling the accelerated development of stable mutant lines. It is expected to produce at least one mutant rice line tolerant to low nitrogen concentrations, with potential for inclusion in breeding programs. This research represents a significant step towards a more sustainable, efficient, and technologically advanced agriculture, with a direct impact on the productivity and food security, which constitutes an advancement of the state of the art in plant breeding in Costa Rica and Panama.

Desarrollar mutantes de arroz mediante irradiación gamma adaptados a condiciones edáficas limitantes para favorecer la conservación y manejo sostenible del suelo.

Biotecnología Vegetal del CIB