The aim of this study was to visually evaluate the occurrence of fungal diseases in the conventional production fields of spring barley 'Sanette' during the growing season of 2018. Another aim was to identify the fungal organisms, which survive in the seeds using molecular methods. For the research, three coventional production fields were selected from the lands of the Tiido farm in Ida-Viru County, where the late-spring barley 'Sanette' was grown. Each of the fields had three separate disease observation sites, where the diseases occurrance and the impact strength was detected during the growing season of 2018. The barley seeds for molecular examination were collected as a bulk sample from all fields. The fungi retained in the seed were transferred to the pure culture, their DNA was extracted and the fungal species or genus was identified by sequencing the fungal ITS region. In the production fields, the only disease that occured during the growing season on barley plants was spot blotch caused by Bipolaris sorokiniana, to which the cultivar 'Sanette' was susceptible. The plants got infected in growth stages 21-25 and the signs of the disease increased until harvesting in the growth phase 90. 12 different fungal species were identified from the barley seeds, mainly Alternaria spp., Fusarium spp., Pyrenophora spp. and B. sorokiniana species. In addition, also some mold species were isolated from the genera Rhizopus, Rhizomucor, Lichtheimia, Cladosporium, Penicillium and Aspergillus. The results of the research showed that in the course of visual disease observations, several pathogens were not detected in the field, including Pyrenophora spp., Alternaria spp., Fusarium spp., whose symptoms did not appear in the vegetation period and were therefore not detectable during field surveys. In the same barley seed, these species were present and were detectable in laboratory conditions using molecular methodology for determination. In the course of the work, Alternaria spp. were isolated and identified from the seeds, which have not been done in Estonia before. These species may have a potential role in causing various diseases in barley plants during the growing season, and also damaging the harvest by production of mycotoxins.

Töö eesmärgiks oli hinnata visuaalselt seenhaiguste esinemist tavatootmisettevõtte suviodra 'Sanette' põldudel 2018. a kasvuperioodil ja määrata molekulaarsel teel selle seemnetes säilivad seenorganismid. Uurimistöö jaoks valiti kolm tavatootmispõldu Ida-Virumaalt Tiido talu maadelt, kus kasvatati hilist suviodra sorti 'Sanette'. Igal põllul oli kolm eraldi vaatluskohta, kus teostati vaatlusi taimehaiguste lööbimise ja lööbimistugevuse kohta 2018. a kasvuperioodi jooksul. Odraseemned molekulaarseks uurimiseks koguti saagist ühendproovina kõikidelt põldudelt. Seemnes säilivad seened viidi puhaskultuuri, eraldati nende DNA ja tehti kindlaks seene liik või perekond ITS regiooni järjestuse sekveneerimise abil. Tootmispõldudel lööbis taimede kasvuperioodil ainult pruunlaiksus, mille haigustekitajaks on Bipolaris sorokiniana, millele oli sort ka vastuvõtlik. Taimed haigestusid kasvufaasides 21-25 ja haigus nähud tugevnesid kuni saagi koristamiseni kasvufaasis 90. Seemnes säilivate seente molekulaarsel uurimisel tuvastati 12 arvatavat seeneliiki. Peamiselt oli tegu Alternaria spp., Fusarium spp., Pyrenophora spp. ja B. sorokiniana liikidega. Lisaks leidus seemnetes ka hallitusseente liike perekondadest Rhizopus, Rhizomucor, Lichtheimia, Cladosporium, Penicillium ja Aspergillus. Uurimistöö tulemused näitasid, et visuaalsete haigusvaatluste käigus jäid põllul tuvastamata mitmed haigustekitajad sealhulgas Pyrenophora spp, Alternaria spp., Fusarium spp., mille sümptomid ei avaldunud taimikus ega olnud seetõttu põlluvaatluste käigus määratavad. Samas odraseemnetes need liigid esinesid ja olid tuvastatavad laboratoorsetes tingimustes, kasutades määramiseks molekulaarset metoodikat. Töö käigus tuvastati teadaolevalt esmakordselt Eestis suviodra seemnetest Alternaria liike, millel võib potentsiaalne roll olla erinevate haiguste põhjustamisel odra taimedel kasvuperioodil ning saagi kahjustamisel ka läbi mükotoksiinide produtseerimise.