High-temperature-tolerant mungbean (Vigna radiata L.) lines produce better yields when exposed to higher CO₂ levels

ABSTRACT

Increasing global air temperatures, along with rising CO₂ levels, are causing concerns about reducing available freshwater resources and altering cropping patterns. They may influence overall growth and production pattern of crop plants. These likely changes would become major limiting factors for future sustainable food production largely in the tropics and subtropics. Thus, understanding physiological responses hold the key to determining the functional relationship between the environment and crop performance. We explore here the impact of rising CO₂ on the growth and yield traits of a few selected high-temperature (HT)-tolerant mungbean lines, which we earlier screened for HT tolerance using a physiological assay under managed growth conditions. The HT-tolerant lines grown under elevated CO₂ levels (550 and 700 μL L⁻¹) showed a considerable improvement in growth rates (13.5%, 67.8%, and 46.5% in plant height, leaf area, and total dry matter, respectively) and pod and seed yield (48.7% and 31.7%, respectively), compared to local checks under the same environments. Interestingly, the symptoms of accelerated pod maturity were also observed in most of these lines. The outcome of the study would undoubtedly open up opportunities for increased yield potentials of legumes under the conditions of the warming climate and elevated levels of carbon dioxide.

KEYWORDS:

• Elevated CO₂ levels
• growth physiology
• high-temperature-tolerant mungbean
• photosynthetic efficiency
• pod maturity

Acknowledgments

We thank USAID-AIP for partial assistance, students, and staff of the Department of Botany at Panjab University for supporting the heat stress study and Dr Mamta Sharma/Mr Rameshwar, ICRISAT for providing the OTC facility for CO₂ enrichment assay, and also Dr Vanaja and Mr Satish, scientists from Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad, India, for helping us in gas exchange measurements.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Core funding to support World Vegetable Center’s activities worldwide is provided by the Republic of China (ROC), UK aid, the Australian Center for International Agriculture Research (ACIAR), the United States Agency for International Development (USAID), Germany, Thailand, Philippines, Korea, and Japan.