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obuhvataju mnoge ekonomski, nutritivno i medicinski značajne vrste koje po obimu proizvodnje zauzimaju peto mesto u svetu. Obzirom na stalni nedostatak hrane u svetu, postoji kontinuirana potreba za povećanjem proizvodnje ovih biljnih kultura, a razvoj efikasnih strategija zaštite od patogena predstavlja važan cilj u njihovom gajenju. Fitopatogene vrste gljiva predstavljaju najznačajnije prouzrokovače bolesti kupusnjača, među kojima su i vrste roda Alternaria. U periodu od 2013. do 2016. godine, tokom obilazaka glavnih proizvodnih regiona kupusnjača u Srbiji, na 24 lokaliteta u 22 administrativna okruga, detektovani su tipični simptomi crne lisne pegavosti koje izazivaju Alternaria spp. Uočena je relativno visoka učestalost oboljenja za uljanu repicu (17-43%), ren (30-51%), kupus (22- 53%), brokoli (15-34%), karfiol (14-28%), kelerabu (18-26%) i kelj (21-28%). Iz uzoraka biljaka sa simptomima bolesti identifikovano je 436 izolata Alternaria spp. Rezultati morfoloških i molekularnih analiza su potvrdili prisustvo 8 vrsta, prouzrokovača lisne pegavosti kupusnjača: A. brassicae (141 izolat), A. brassicicola (141 izolat), A. japonica (12 izolata), A. alternata (114 izolata), A. arborescens (12 izolata), A. cheiranthi (8 izolata), A. nepalensis (4 izolata) i A. malvae (4 izolata). Na osnovu filogenetske analize i genealoške mreže ispitivanih sekvenci ITS, GAPDH, Alt a1 i ATP gena, potvrđeno je postojanje jednog multilokusnog haplotipa za A. brassicae, A. cheiranthi i A. malvae; tri haplotipa za A. brassicicola; po dva haplotipa za A. japonica i A. arborescens; dok je 20 haplotipova izdvojeno za A. alternata. Zavisnost distribucije haplotipova u odnosu na domaćina ili geografski region utvrđena je samo za neke delove haplotipske mreže izolata A. alternata, A. brassicicola i A. japonica. Na testiranim biljkama, najpatogenija je bila A. brassicicola, zatim A. brassicae i A. japonica, dok su ostale izolovane vrste Alternaria bile značajno manje patogene. Izolati A. alternata uglavnom su bili slabo patogeni, ali se izdvojila i grupa nepatogenih izolata, 15 izolata haplotipa 20 i 4 izolata haplotipa 4. Iako genetički različiti, patogeni i nepatogeni izolati A. alternata imali su visok stepen srodnosti, što sugeriše da su faktori patogenosti ili virulencije u ovoj filogenetskoj liniji nestabilniji nego što je slučaj kod ostalih vrsta. Biljke rena su bile najotpornije na infekciju Alternaria spp. pa tako vrste A. alternata, A. arborescens, A. cheiranthi i A. nepalensis nisu pokazale virulentnost na ovom domaćinu. U svim ispitivanim slučajevima stariji listovi su bili više oštećeni od mladih, što ukazuje na različitu osetljivost biljaka prema bolesti u različitim razvojnim stadijumima. Pored svega navedenog, ispitivanja patogenosti na različitim domaćinima ukazala su na potencijal Alternaria spp. za unakrsnu infekciju različitih zasada kupusnjača. Zabeležene vrednosti stope rasta i intenziteta sporulacije izolata na 0 °C, 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C i 40 °C istakle su razlike u evolucionim strategijama između vrsta. Izolati A. alternata su imali najširi opseg optimalnih temperatura i najbržu stopu rasta, A. brassicicola najveći intenzitet sporulacije i visoku stopu rasta, dok su optimalne temperature za A. brassicae izolate bile niže, a plastičnost spora na različitim temperaturama najveća u poređenju sa drugim grupama. Takođe, zaključeno je da učestalost javljanja A. brassicae i A. brassicicola na renu, kupusu, brokoliju, kelerabi i kelju u Srbiji može biti povezana sa sezonskim fluktuacijama temperature. Na osnovu mikrosatelitskih lokusa za populacije A. brassicicola uočen je visok genetički diverzitet populacije, netipičan za vrste koje se aseksualno razmnožavaju. Uprkos visokom genetičkom diverzitetu ove vrste, prisutvo mutacija koje su odgovorne za promenu osetljivosti na fungicid azoksistrobin nisu detektovane... The plants from family Brassicaceae are distributed throughout the world, consisting of a wide range of economically, nutritionally and nutraceutically important crops, ranking 5th in the global production. The global demand for cruciferous plants makes it one of the fastest-growing crops in production with a need for increasing growing area and productivity, both of which depend on effective pathogen control strategies. Fungal pathogens causing leaf spot disease are one of the most limiting factors for growing Brassica crops and Alternaria spp. cause serious losses throughout the world. During the survey, period 2013-2016, a typical Alternaria-induced dark leaf spot lesions were noticed at 24 localities of 22 administrative districts of major production areas of the cruciferous crops in Serbia. From the symptomatic plants, 436 isolates of Alternaria spp. have been collected and estimated incidence of disease was relatively high, for rapeseed (17-43%), horseradish (30-51%), cabbage (22-53%), broccoli (15-34%), cauliflower (14-28%), kohlrabi (18-26%) and kale (21-28%). In this study, morphological, molecular and pathogenic analyses were congruent and identified 8 pathogens causing leaf spot disease: A. brassicae (141 isolates), A. brassicicola (141 isolates), A. japonica (12 isolates) , A. alternata (114 isolates), A. arborescens (12 isolates), A. cheiranthi (8 isolates), A. nepalensis (4 isolates) and A. malvae (4 isolates). Multigenetic analyses and haplotype network of ITS, Alt a1, GAPDH, and ATP sequences revealed: one multilocus haplotype for A. brassicae, A. cheiranthi and A. malvae; three haplotype groups for A. brassicicola; two for A. japonica and A. arborescens; and 20 haplotypes for A. alternata isolates. The haplotype distribution dependency on host or geographical regions was confirmed only for some parts of haplotype network of A. alternata, A. brassicicola and A. japonica isolates. The pathogenicity test showed that A. brassicicola was the most virulent, A. brassicae and A. japonica exhibited the same level of pathogenicity, while the other species showed less pathogenic capability for tested plants. A. alternata population was generally weakly pathogenic with two non-pathogenic groups, 15 isolates of haplotype 20 and 4 isolates of haplotype 4. Although these groups of pathogenic and non-pathogenic isolates were genetically separated, the analyses showed they are closely related, suggesting that pathogenicity or virulence factors are more unstable in this phylogenetic lineage. The difference in susceptibility among plants was indicated, where horseradish plants were the most resistant, A. alternata, A. arborescens, A. cheiranthi and A. nepalensis have not shown virulence on this host. Old leaves were more severely affected than young leaves in all cases, indicating an age-related difference in the susceptibility of the plants. All species indicated potential for cross-infection, and the same haplotypes of particular species were isolated from different cruciferous hosts in Serbia, suggesting the presence of one persistent Alternaria population on multiple Brassica hosts in the region. The data recorded on rate of growth and sporulation intensity of isolates at 0 °C, 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C and 40 °C revealed significant differences in evolutionary strategies among species: A. alternata had the widest optimum range and the fastest growth rate; A. brassicicola showed the highest sporulation intensity and high growth rate; and A. brassicae expressed lower optimum temperatures for sporulation and significant plasticity of spore dimensions compared to the other species. Temperature response and prevalence of species in the field suggested that incidence of A. brassicae and A. brassicicola species was related to seasonal temperature fluctuations in the all tested hosts except rapeseed. Analysis of microsatellite loci revealed high genetic diversity of A. brassicicola, not a common feature for species in which only asexual reproduction was noticed...