INHERITANCE OF ALUMINUM TOLERANCE IN WHEAT

Abstract

Aluminum tolerant and aluminum sensitive wheat (Triticum aestivum L. em Thell) cultivars representing different parental backgrounds were used to study the inheritance of response to aluminium. F1, F2, F3, and backcross generations from crosses of four soft red winter wheat cultivars were grown in nutrient solutions containing 8 ppm aluminum. There appeared to be no genetic differences between the two sensitive parents (Redcoat and Arthur) for aluminum response. The two tolerant parents (Seneca and Thorne) also exhibited no apparent genetic differences for aluminum response but were decidedly superior to the sensitive parents in the presence of aluminum. F1, F2, and backcross data from sensitive/tolerant crosses indicated that sensitivity was conditioned by a single recessive gene. Selection for aluminum sensitive plants in the F2 was effective, based upon their F3 family means. Selection for intermediate or tolerant plants was less effective, indicating that the inheritance was more complex than a single gene. Leaf length and roots/plant were found to be inferior to root length as measures of aluminum tolerance. These nutrient culture results were consistent with the occurrence of sensitive and intermediate lines and the absence of highly tolerant lines from breeding populations selected on limed soils.