The Resistance of Twelve Varieties of Triticum Vulgare to Erysiphe Graminis Tritici

Abstract

A genetic study was made of the resistance of 12 vars. of T. vulgare to a South Australian isolate of E. graminis tritici. This collection has been resolved into 2 pathogenic components which may be differentiated by their reactions on the Chul var. The 12 vars. studied fall into 3 natural groups. Eight vars. of group A possess a common gene, Mlt, which confers resistance to mildew at all stages of growth. Mlt is completely linked with a gene conferring resistance to race 135AB of Puccinla triticina. Group B is represented by a single var. which derives its mildew resistance from a 2d gene, Mlu. This var. is susceptible to P. triticina 135AB. The vars. of group C are resistant to mildew from the 3 -leaf stage onwards and apparently owe their resistance to a 3d gene, Mls. These vars. are also susceptible to P. triticina 135AB.