Three hundred ninety one (391) spring wheat introductions from Asian, Middle Eastern and Mediteranean areas were screened for resistance to races C17, C20, C25, C49, C53 and C57 of Puccinia qraminis tritici; races 1, 5, 9, 15 and bulks 1, 4 and l0 of Puccinia recondita; races T2, T10, T13 and T39 of Ustilago tritici and to 6 isolates of Drechslera tritici-repentis prevalent in western Canada. Of the 34 introductions resistant to P. graminis tritici, 15 were genetically studied using F2 segregation data derived from the progeny of the crosses involving resistant introductions, their corresponding near isogenic lines and stem rust universal suscepts. Eleven of these were found to carry single Sr genes for resistance, notably, Sr30, Sr13 and Sr15. Of the 70 introductions resistant to P. recondita, 28 were studied and 9 were found to carry known Lr genes for resistance, notably Lr10 and the genes present in RL6057 and RL6061. Twenty two introductions are believed to carry either 1 or 2 unidentified dominant, recessive, partially dominant and/or complementary genes for resistance to either stem or leaf rust. Five introductions were immune and 6 highly resistant to the 4 races of U. tritici. Sixty-nine introductions were resistant to D. tritici-repentis . These were arbitrarily classified into 10 'phenotypic classes' according to their reactions to the 6 isolates used.

Three hundred ninety one (391) spring wheat introductions from Asian, Middle Eastern and Mediteranean areas were screened for resistance to races C17, C20, C25, C49, C53 and C57 of Puccinia qraminis tritici; races 1, 5, 9, 15 and bulks 1, 4 and l0 of Puccinia recondita; races T2, T10, T13 and T39 of Ustilago tritici and to 6 isolates of Drechslera tritici-repentis prevalent in western Canada. Of the 34 introductions resistant to P. graminis tritici, 15 were genetically studied using F2 segregation data derived from the progeny of the crosses involving resistant introductions, their corresponding near isogenic lines and stem rust universal suscepts. Eleven of these were found to carry single Sr genes for resistance, notably, Sr30, Sr13 and Sr15. Of the 70 introductions resistant to P. recondita, 28 were studied and 9 were found to carry known Lr genes for resistance, notably Lr10 and the genes present in RL6057 and RL6061. Twenty two introductions are believed to carry either 1 or 2 unidentified dominant, recessive, partially dominant and/or complementary genes for resistance to either stem or leaf rust. Five introductions were immune and 6 highly resistant to the 4 races of U. tritici. Sixty-nine introductions were resistant to D. tritici-repentis . These were arbitrarily classified into 10 'phenotypic classes' according to their reactions to the 6 isolates used.

Loose smut of barley, caused by fungal pathogen Ustilago nuda is one of the major concerns throughout the globe for barley producers. The infection takes place without exhibiting any obvious symptoms and an infected seed lot can only be identified at the heading stage when the fungal teliospores emerge at the place of crop. The percentage losses on yield are directly proportional to the occurrence of infection. Currently available detection methods include seed health testing protocols which are time-consuming and cumbersome. With the globalization of the international market and increased crop demand, development of rapid disease screening methodologies has become an essential focus in the field of plant pathology. The present study sought to develop a rapid probe-based detection method for screening of U. nuda with real-time qPCR. Two U. nuda specific primer pairs were compared using standard PCR alongside optimization of real-time qPCR assay. The advantage of high fidelity DNA polymerase for amplification of U. nuda genomic DNA was recorded. U. nuda genomic DNA was amplified and cloned into a vector which was further used for generation of a quantification curve with a specific probe. The qPCR assay developed in this study was successful in the detection of as little as 43 copies of U. nuda genomic DNA. With studies involving larger sample size and field samples, this assay can be improved for enhanced sensitivity and specificity which can help in monitoring infection from DNA extractions of barley seeds and further improving the current microscopic detection methods.