Compatibility of Erysiphe graminis Hybrids f. sp. secalis X f. sp. Tritici with Wheat Lines Involving Resistance Genes from Rye

Compatibility of hybrid cultures Erysiphe graminis ff. sp. secalis (SI) ×tritici (t2) was tested in the laboratory with wheat cultivars involving different resistance genes and with two rye cultivars. Segregation was observed on wheat without resistance gene and with resistance genes Pm1, Pm3b and Pm3c compatible with t2, but not on wheat with resistance gene Pm2, Pm 3a, Pm 4a and Pm 5 incompatible with t2, nor on rye. It was obvious that S1 involves avirulence genes to Pm1, Pm2, Pm 3a, pm 3b, Pm 3c, Pm 4a, Pm 5. Segregation was found on wheat cultivars involving rye resistance genes Pm 7 (Transfed) and Pm 8 (Kavkaz), but cv. Transec (Pm7) was incompatible with all cultures used, because Transec involves another gene for resistance. The results indicate that hybridization between formae speciales secalis and tritici of the fungus can be a source of fungus compatibility with wheat with rye resistance, even in field conditions.