Host range of various leaf rust populations in Iran

In order to investigate the host range of various populations of causal agent of wheat leaf rust, Puccinia. recondita sensu lato, during 2010-2016, fifty isolates of the pathogen were collected from different hosts of Poaceae in various parts of Iran including: Ardabil, Fars, Golestan, Ilam, Kerman, Khuzestan, Khorasan Razavi, Kurdistan, Mazandaran and West Azerbaijan. Pathogenicity of all isolates on seven hosts, including bread wheat (Triticum aestivum L., cv. Boolani), durum wheat (Triticum durum Desf., cv. Karkhe & cv. Yavaroos), barley (Hordeum vulgare L., cv. Afzal), oat (Avena sativa L.), rye (Secale montanum Guss.) and triticale (Triticosecale Wittm. Ex A. Camus) was examined. Results indicated that all isolates had high disease severity on bread wheat (cv. Boolani) and triticale. Bread wheat isolates were avirulent on all hosts except for triticale, which showed a hypersensitive reaction or small, dispersed pustules. Triticale isolates were only pathogenic on triticale and bread wheat. Durum wheat isolates were virulent on bread wheat, durum wheat, and triticale, and were avirulent on barley and rye plants. Oat isolates showed an avirulence response on barley, rye and various genotypes of durum wheat and rye. Barley isolates were also pathogenic on bread wheat, triticale and barley and avirulent on durum wheat and rye. Although wild barley isolates were virulent on bread wheat, durum wheat, and triticale, they were avirulent on other hosts. Oat is a non-host for all leaf rust isolates, except for its own isolates. The findings indicate that in the absence of wheat, leaf rust populations are able to survive on other members of the Poaceae family.