COMPARISON OF CONTROLS ON DEVELOPMENT IN BREEDING LINES FROM AUSTRALIAN AND CIMMYT ICARDA WINTER AND FACULTATIVE WHEAT BREEDING PROGRAMS/

This study sought to compare developmental controls in breeding and pa rental lines utilized within two winter wheat improvement programs, on e Australian and a CIMMYT/ICARDA program based in West Asia. Developme ntal controls considered were intrinsic earliness, and responses to ph otoperiod and to vernalization. The reliability with which each contro l on development had been measured was tested in separate experiments using the wheats utilized in the Australian program. Measures of intri nsic earliness showed significant agreement between experiments, bette r agreement being found for response to photoperiod and between integr ated response to vernalization and time to double ridge after late sum mer sowings. The wheats utilized in the CIMMYT/ICARDA programs were fo und to be quick in intrinsic earliness, and to possess little response to photoperiod. While these controls varied more for the wheats utili zed in the Australian program, commercial Australian winter wheats wer e similar to the CIMMYT/ICARDA lines. Lines utilized by both programs were represented by types with spring, facultative and winter habit. T he 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 fi nd a good proportion of segregates, from crosses between the Australia n and the CIMMYT/ICARDA winter wheats, to be developmentally adapted t o south-central New South Wales. This suggests CIMMYT/ICARDA winter wh eats provide a matching pool from which to access germplasm to introdu ce new characters into Australian winter wheats.