NEW DATA ON JUVENILE RESISTANCE TO FOLIAR DISEASES OF RESISTANCE SOURCES IN TRITICALE

Abstract

The search of triticale sources for resistance to fungal diseases from the collection of N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) led to the identification of many resistant accessions. To confirm the breeding value, it is necessary periodically to reevaluate the plants resistance. The seedling resistance in 187 triticale accessions from VIR collection to 4 diseases was studied. Earlier in 2008-2024, in the Russian scientific literature, these accessions were described as resistant to leaf rust – 76 accessions, dark-brown leaf spot blotch – 64, septoria nodorum blotch – 29 and powdery mildew – 39. According to the experiment results, all the samples studied were susceptible to dark-brown leaf spot blotch and septoria blotch. Out of 76 samples, only 28 earlier identified in our work confirmed resistance to leaf rust. Out of 39 samples described as highly resistant to powdery mildew, in this work only 7 accessions confirmed the resistance. We recommend using the identified resistant accessions as reliable sources for triticale breeding. Thus, triticale studies confirm the conclusion, previously made for other cereals, about the susceptibility to diseases of the most accessions described in Russian scientific literature as highly resistant to them. In order to identify reliable sources of resistance to diseases, plant material should be studied in at least 4 independent experiments and at least one additional time when changing populations for inoculation. Resistance assessments are unacceptable with use "benzimidazole" technique, the same as in case of hemibiotrophic fungi, early (3-5 days after inoculation) assessments of diseases development.