IMPACT OF CIMMYT VARIETIES ON THE GENETIC DIVERSITY OF WHEAT IN AUSTRALIA, 1973-1993

Wheats derived from germplasm developed by the International Maize and Wheat Improvement Center (CIMMYT) have been grown widely in Australia since the early 1970s. The impact of CIMMYT germplasm on the genetic diversity of Australian wheats over the 20 years to 1993 is examined. On average, the diversity at a national level remained relatively high throughout the period, but this finding varied markedly between State s. While there was significant increase in diversity in South Australi a and Western Australia, there was a narrowing of the genetic base of varieties grown in the eastern States, especially Victoria, accompanyi ng the widespread use of CIMMYT germplasm.