Aspergillus niger is the causal organism of "black mold" disease of fruits and vegetables. The objective of the present investigation was to characterize the pathogen morphologically in vitro and to confirm its molecular identity and phylogenetic position by the sequence of ITS region of rDNA. A. niger LKO1 was isolated from soil and cultured in PDB and PDA media. The characteristic of growth was monitored and the reproductive structures were analyzed. After 3 days of growth, the diameter of each colony was 1.5 cm, after which the colony was extended its diameter 1 cm per day and subsequently black conidiophores were formed with black pigmented spore heads carrying numerous conidia. Fungus was also characterized using molecular methods based on ITS-PCR (GenBank accession number MK696283). The amplified sequence was compared with the available sequences in the NCBI GenBank. The sequence showed 100% similarity with other isolates of A. niger. The isolation, morphological characterization and sequencing of ITS region of rDNA will help in further research on the management of this plant pathogen and its commercial utilization.

Soil-borne fungi Pythium aphanidermatum causes damping-off of cucumber, coriander and other economically important plants in India and presumably in many other countries. The objective of the present investigation was to characterize the pathogen morphologically in vitro and to confirm its molecular identity by the sequence of ITS region of rDNA. P. aphanidermatum was isolated from soil and cultured in PDB broth and PDA solid media. The characteristic of growth was monitored and the reproductive structures were analyzed. Hyphae were grown with a daily increment of 2.5-3.0 cm on PDB. Sporangia were swollen, multinucleate and usually measure 10-50 μm in diameter. Oogonia were found mostly terminal, spherical, 22-27 µm in diameter. Fungus was also characterized using molecular methods based on ITS-PCR. The amplified sequence was compared with the available sequences in the NCBI GenBank. The sequence showed 99% similarity with other species of Pythium. Based on the morphological and molecular characters isolate was confirmed as Pythium aphanidermatum. The isolation, morphological characterization and sequencing of ITS region of rDNA will add knowledge to the scientific community for proper identification and in-depth research on the management of this plant pathogen.