جستجوی مقالات مرتبط با کلیدواژه "زنگ برگی" در نشریات گروه "گیاهپزشکی"

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.

Wheat leaf rust (Puccinia triticina Eriksoon) is of the most injurious wheat diseases that prevails throughout areas where wheat is grown. An identification of virulence factors along with differences in the population of pathogen in different wheat growing regions is necessary for an enhancement of resistant cultivars with effective resistant genes to leaf rust. To accomplish the purpose, a leaf rust Trap Nursery containing 37 near isogenic lines in addition to Bolani susceptible cultivar as check were planted under natural infection conditions in Gorgan (with an application of mist irrigation) and Gonabad (with no mist irrigation) locations during 2002-2007. Reaction to the disease of each line was recorded at the flag leaf stage and when infection on the Bolani susceptible cultivar was at its maximum level for infection rate and type. "S" reaction indicated virulence while "O, R, MR and MS" reactions were indicative of as avirulence. Results showed that virulence was detected for genes Lr1, Lr2c, Lr3, Lr3ka, Lr3bg, Lr10, Lr11, Lr12, Lr13, Lr14a, Lr14b, Lr15, Lr16, Lr17, Lr18, Lr20, Lr21, Lr22a, Lr22b, Lr23, Lr24, Lr26, Lr30, Lr32, Lr33, Lr34 and either Lrb at one or both Gorgan and Gonbad locations. Virulence was observed for genes Lr3, Lr10, Lr14b, Lr17, Lr18, Lr26 and Lr34 only at Gorgan site. No virulence was observed for genes Lr2a, Lr2b, Lr19, Lr25, Lr28, Lr29, Lr35, Lr36 and Lr37 at these locations. Avirulence due to the resistance of the above resistant genes provides the possibility of the use of these genes in breeding programs to develop varieties resistant to wheat leaf rust.

The interaction between root-colonizing Pseudomonas fluorescens strain CHA0mcherry and three wheat cultivars (Bolani, Roushan, Forno) was studied as a phenomenon to be employed in the control of Wheat Leaf Rust Disease (Puccinia triticina). CHA0mcherry was inoculated using seed treatment method. The application of CHA0mcherry reduced the number of pustules on leaves via inducing systemic resistance, specially in Bolani cultivar. The non-inoculated Bolani and Forno cultivars exhibited the highest infection of the leaf rust. A study of the bacteria-wheat-pathogen interaction indicated that Forno was the most responsive root- colonized variety to the bacterium. The lowest colonization was observed within the rhizosphere of Roushan cultivar. Interaction between pathogen and cultivars was shown to lead to increase of peroxidase and Phenylalanine Ammonia Lyase (PAL) activity in leaves. In summary, the results showed negative correlations between the bacterial colonization (cfu per mg dry root) and the number of rust pustules on the leaves. There was also a significant correlation noted between PAL activity and disease severity.