SENSITIVITY OF HEXAPLOID AND OCTOPLOID TRITICALES AND THEIR PARENT SPECIES TO COPPER DEFICIENCY

The tolerance of two triticales to soil of low copper status was determined in deep pots in a glasshouse experiment, and compared with the tolerance of their wheat and rye parent types. Both tetraploid and hexaploid wheats were extremely sensitive to copper deficiency, producing no grain without copper added to the soil. In contrast, rye and the hexaploid triticale were completely tolerant of the copper-deficient soil, producing as much grain without added copper as at the highest rate of copper supply. The octoploid triticale produced about 60% of maximum grain yield in the unamended soil, a performance intermediate between its rye and hexaploid-wheat parents. The cause of grain failure in the wheats was pollen sterility induced by copper deficiency, and this was related to low uptake of copper into the shoot and heads of wheat from the unamended soil. The pattern of uptake of zinc was quite different from that of copper in these plants, which suggests that a specific uptake mechanism for copper exists in rye which is genetically controlled and transferable to triticale, its hybrid with wheat. The copper efficiency so conferred on triticale would appear to be adequate for most field situations where copper deficiency exists. © 1979 CSIRO.