Morphological and molecular identification of pathogenic fungal strains on postharvest Dongzao jujube fruit during cold storage

Nine pathogenic fungal strains on Dongzao jujube in China were identified and analyzed according to the morpho-logical characteristics and ITS sequences. Morphological studies showed that strains DH2,DH4,DJ3,DJ4,LW3 and LW5 generated spores on potato dextrose agar plates and slides. Strain LW4 generated distinct conidiomata and single-celled oval conidia. Strains DH4,DJ3,DJ4 and LW5 produced muriform conidia. The rDNA ITS regions of these pathogens were ampli-fied by PCR and then sequenced. After analyses of their ITS sequences, a phylogenetic tree was obtained from the program NJ (Neighbor-joining), together with the sequence of related strains which were downloaded from GenBank. The results of morphological observation and molecular detection of these nine strains showed that DH4, DJ3, DJ4 and LW5 belong to Al-ternaria spp.; DH1 and LW4 belong to Phomopsis spp.; DH2 belongs to Phoma sp.; LW3 belongs to Exserohilum rostratum and DJ5 belongs to Stemphylium sp.