Early Maturity in Wheat for Adaptation to High Temperature Stress

Abstract

High temperatures pose a serious threat to productivity maintenance and enhancement in wheat. A strategy that has come forward in the CIMMYT breeding program is the development of high yielding early maturing lines that are adapted to high temperature stress especially for South Asia. The high temperature stress in South Asia is classified into terminal high temperature stress where the high temperatures stress occurs during grain filling stages, and continual high temperature stress, where high temperature persists across the wheat growing season. The new high yielding, early maturing and heat tolerant CIMMYT wheat lines were evaluated for grain yield and adaptation across diverse locations in South Asia and Mexico. Trials were conducted for three consecutive years 2009–2010, 2010–2011, and 2011–2012. The results suggest that CIMMYT lines with high yields and early maturity, selected under normal and late sown condition in Cd. Obregon, Mexico, have the potential to adapt and outperform normal maturing check varieties under terminal and continual high temperature stress in South Asia. Earliness favored the plants to escape terminal high temperature stress and also promoted an efficient utilization of available resources under continual high temperature stress to achieve higher grain yield. The simultaneous enhancement of grain yield potential and heat stress tolerance of early maturing wheat lines is likely to be beneficial in enhancing productivity under high temperature stress across South Asia.