Prvi nalaz teleomorfnog stadijuma prouzrokovača sive pegavosti lista i klasa pšenice Leptosphaeria nodorum u Srbiji

Abstract

Parastagonospora nodorum (teleomorf Leptosphaeria nodorum) je prouzrokovač sive pegavosti lista i klasa pšenice. Prvi put je otkriven na pšenici 1845. godine i čest je u regionima sa relativno visokim, ili periodično visokim padavinama. P. nodorum izaziva simptome na svim nadzemnim delovima biljke, tj. listovima, stablu, plevama i osju. Patogen prezimljava na žetvenim ostacima pšenice u obliku pseudotecija i piknida. Askospore oslobođene iz pseudotecija obično čine izvor primarnog inokuluma, međutim, konidije oslobođene iz piknida sa žetvenih ostataka takođe mogu izvršiti zarazu klijanaca. Pored toga, poznato je da gljiva preživljava i na semenu u vidu dormantne micelije, tako da i zaraženo seme može biti izvor primarne infekcije. Tokom proizvodne 2022/2023. godine sume padavina u aprilu (63,9 mm) i maju (124,8 mm ) nadmašile su sedamneasetogodišnje proseke čime su se stvorili uslovi za pojavu prouzrokovača sive pegavosti lista i klasa pšenice. Mikroskopskim pregledom pega zaraženih listova pšenice utvrđeno je prisustvo polnog stadijuma (L. nodorum) prvi put u Srbiji. Bespolni stadijum (P. nodorum) uočen je na uzorcima zaraženih klasova na više sorti. Ovaj rad upućuje da se u budućnosti mora posvetiti posebna pažnja praćenju uslova koji bi mogli dovesti do jače pojave ovog patogena na proizvodim površinama pšenice u Srbiji.

Parastagonospora nodorum (teleomorph Leptosphaeria nodorum) is the causal agent of septoria nodorum blotch (SNB). It was first discovered on wheat in 1845. and is common in regions with relatively high or periodically high rainfall. P. nodorum causes symptoms on all above-ground parts of the plant, including leaves, stems, glumes, and awns. The pathogen overwinters on wheat crop residues in the form of pseudothecia and pycnidia. Ascospores released from pseudothecia typically serve as the primary source of inoculum, but conidia released from pycnidia on crop residues can also infect seedlings. Additionally, the fungus is known to survive on seeds in the form of dormant mycelium, making infected seeds a potential source of primary infection. During the 2022/2023 growing season, precipitation totals in April (63.9 mm) and May (124.8 mm) exceeded seventeen-year averages, creating conditions conducive to occurence of SNB. Microscopic examination of lesions on leaves of wheat variety revealed the presence of the sexual stage (L. nodorum) for the first time in Serbia. The asexual stage (P. nodorum) was observed on infected ears of different varieties. This study highlights the need for more attention in monitoring conditions that could lead to outbreak SNB in wheat production areas in Serbia.