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Late blight, a disease caused by oomycota, Phytophthora infestans, is a greater threat to the potato crop than any other disease in Mauritius. This disease remains the most challenging to manage once symptoms have appeared, thus requiring rapid detection for effective disease management. The aim of this study was to compare different methods for early detection of the causal agent of potato late blight. Conventional culture-based methods involved the direct isolation of P. infestans from infected leaves on Carrot Piece Agar (CPA), Carrot Sucrose Agar (CSA), Commercial Potato Dextrose Agar (CPDA), Fresh Potato Dextrose Agar (FPDA-1 and FPDA-2), Oatmeal Agar (OMA), Pea Sucrose Agar (PSA) and Water Agar (WA) without antibiotic supplementation. Mycelial growth on agar was subsequently identified using molecular techniques. A culture-independent method was also attempted whereby total genomic DNA was directly extracted from symptomatic leaves with mycelial growth followed by PCR amplification with ITS5/ITS4 primers and sequencing. The different media ranked in the following decreasing order of performance: PSA >>> CSA ~ FPDA-1 > CPA ~ CPDA ~ OMA, with growth appearing on PSA within 7 days without contamination. DNA sequencing confirmed the identity of the agent recovered from PSA and from diseased leaves to be P. infestans. Findings of this study point to an optimum nutritive medium for recovering and culturing P. infestans from leaves with foliar blight without the use of antibiotics. Alternatively, a cultureindependent method can be used for rapid detection and identification during routine disease surveillance.

Sixteen samples of sorghum seed (Sorghum bicolor (L.) Moench.) 'Alba', 'Gold', 'Prima' and 'Reform' were analyzed in the localities of Bački Petrovac and Čantavir in the period 2009-2011. Tipresence of species belonging to the genera Epicoccum, Fusarium, Alternaria, Aspergillus and Penicillium was established in single and mixed infections. From the infected sorghum seed, monosporial cultures identified as Epicoccum nigrum based on morphology, proved their pathogenicity on artificially inoculated sorghum seedlings. Molecular identification was performed by PCR and amplification of the ITS region of ribosomal DNA. Gene sequences of selected isolates 291-09 (JQ619838) and 315-09 (JQ619839) exhibited 99-100% nucleotide identity with the sequences of 31 isolates of E. nigrum deposited in the GenBank. It obtained results represent the first detailed characterization of E. nigrum in Serbia. The presence of a large number of phytopathogenic fungi on sorghum seed should be further investigated in order to clarify their relationships and relative significance.

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