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Rumena rja Puccinia striiformis Westend. je bolezen trav in žit. Povzroča jo obligatni parazit P. striiformis, ki ima izrazito sposobnost za množične okužbe. Okužba z rumeno rjo je ena izmed najpomembnejših glivičnih obolenj, ker okužuje najpomembnejše krušno žito na svetu, pšenico. Izguba pridelka pšenice zaradi rumene rje je ocenjena na najmanj 5,5 milijonov ton letno. Šest do sedem dni po okužbi s patogenom, se na rastlini pojavijo klorotična območja, deset do štirinajst dni kasneje pa so vidni pomarančasto oranžni trosi, s katerimi se bolezen širi. Za rumeno rjo je značilno, da z vetrom ali transportom zlahka osvaja nova območja zaradi sposobnosti prilagoditve vremenskim razmeram in povečane agresivnosti novih sevov. Rodova Berberis in Mahonia sta lahko vmesna gostitelja rumene rje. Vse to nakazuje na to, da rumena rja zares postaja nevarna bolezen pšenice tudi na tistih območjih, kjer prej ni bila gospodarsko pomembna. Po svetu so bile najhujše epidemije po letu 2000, v Sloveniji pa je bila pšenica najbolj prizadeta leta 2014 in 2016. Yellow rust Puccinia striiformis Westend. is a wheat and grass disease. It is caused by an obligate parasite P. striifomis, which has an extraordinary capability for mass infections. Infection with yellow rust is one of the most serious fungal diseases, because it infects the most important field crop in the world – wheat (Triticum aestivum L.) The loss of wheat crop because of yellow rust infection is estimated to be at least 5,5 tons annualy. Plant chlorosis appears six to seven days after infection with patogen and ten to fourteen days later orange uredospores, with which the disease spreads, can be seen on the plant. It is characteristic of yellow rust that it can easily spread and infect new regions by transport and wind, because of its adaptability to weather conditions and increased agressivety of new strains. Genera Berberis and Mahonia can be alternate hosts of yellow rust. It all indicates that yellow rust is becoming a dangerous wheat disease even in regions where it hasn't been economically important before. The worst epidemics around the world were after year 2000 with years 2014 and 2016 being the worst in Slovenia. |
