Comparison of controls on development in breeding lines from Australian and CIMMYT/ICARDA winter and facultative wheat breeding programs

Abstract

This study sought to compare developmental controls in breeding and parental lines utilized within two winter wheat improvement programs, one Australian and a CIMMYT/ICARDA program based in West Asia. Developmental controls considered were intrinsic earliness, and responses to photoperiod and to vernalization. The reliability with which each control on development had been measured was tested in separate experiments using the wheats utilized in the Australian program. Measures of intrinsic earliness showed significant agreement between experiments, better agreement being found for response to photoperiod and between integrated response to vernalization and time to double ridge after late summer sowings. The wheats utilized in the CIMMYT/ICARDA programs were found to be quick in intrinsic earliness, and to possess little response to photoperiod. While these controls varied more for the wheats utilized in the Australian program, commercial Australian winter wheats were similar to the CIMMYT/ICARDA lines. Lines utilized by both programs were represented by types with spring, facultative and winter habit. The dearest differences between programs were that CIMMYT/ICARDA winter wheats appeared to have much stronger response to vernalization than the Australian winter wheats. These findings suggest breeders would find a good proportion of segregates, from crosses between the Australian and the CIMMYT/ICARDA winter wheats, to be developmentally adapted to south-central New South Wales. This suggests CIMMYT/ICARDA winter wheats provide a matching pool from which to access germplasm to introduce new characters into Australian winter wheats.