Developing Stress-Resilient Maize for Asian Tropics.

Maize is largely grown as rain-fed crop in Asian tropics, which is prone to face variable and unpredictable weather conditions. Climate projections suggest increased weather extremes, including increase in growing season temperatures, intermittent droughts and waterlogging within season. The unpredictable trend of their occurrence, sometime more than one extreme condition within a same crop season, increases the likelihood of short-run crop failures and long-run production declines, and eventually threatening food security and livelihood. A vast amount of research has focused on individual stresses such as drought, water-logging, heat, salinity, low nitrogen stress etc., however in farmers’ fields crops are regularly subjected to a combination of stresses. Breeding programs often run independent screens for stresses know to occur in the target environment, selecting genotypes which perform well across a suite of stresses. The major challenge is to put together multiple abiotic stress tolerance and develop productive genotypes tolerant to combination of stresses, such as drought and heat stress, drought and water-logging, drought and low-nitrogen etc. Plant breeding has made remarkable progress in increasing maize yields during the past century. However climate change projections suggest large yield losses in many regions, particularly South Asia. The development of climate-ready germplasm tolerant to individual or combination of stresses to offset these losses is of the upmost importance. Given the time lag between the development of improved germplasm and adoption in farmers’ fields, the development of improved stress-resilient breeding pipelines needs a high priority. Recent advances in molecular breeding and precision phenotyping tools provide powerful tools accelerate breeding gains and dissect stress adaptation. This paper focuses on novel tools and methods for quick and efficient germplasm development strategies for stress-prone ago-ecologies in Asia.