TY  - PRO
AU  - Mondal,S.
AU  - Huerta-Espino,J.
AU  - Singh,R.P.
AU  - Joshi,A.K.
AU  - Crossa,J.
TI  - Earliness in wheat:  A key to adaptation under high temperature stress
PY  - 2013///
N1  - Abstract only
N2  - High temperature stress poses a serious threat to productivity maintenance and enhancement in wheat. The new high yielding, early maturing and heat tolerant CIMMYT wheat lines were evaluated for grain yield and adaptation across diverse heat stressed locations in South Asia and Mexico. Trials were conducted in 2009-2010, 2010-2011, 2011-2012, and 2012-2013 respectively. Each year trials included 28 entries, CIMMYT check variety ?Baj? and a local check. The local check was the best locally adapted variety at each location. The locations were classified by mega environment (ME); ME1 being the temperate irrigated locations with terminal high temperature stress, and ME5 as warm, tropical, irrigated locations where continuous high temperature stress is a major constraint to wheat production. The ME1 locations had cooler temperatures during crop vegetative stages compared to ME5, though the temperatures gradually increased in ME1 and was similar to ME 5 during grain filling. Significant grain yield and kernel weight differences were observed between the ME?s across years. The trial 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 in ME1 as well as early maturing check varieties in ME5. Earliness favored the plants to escape terminal high temperature stress in ME1 but also promoted an efficient utilization of available resources in the ME5 locations and contributed to the final grain yield. Thus 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
ER  -