Morphological and cultural characterization of Phyllosticta zingiberi (Ramkr.) causing leaf spot disease of ginger

Abstract

Isolation of ginger (Zingiber officinale) leaf spot pathogen form the UBKV farm field was done in the laboratory. The isolated pathogen was identified as Phyllosticta zingiberi on the basis of morphological characters as documented in taxonomic keys. The microscopic observation revealed that the pycnidia were globose to subglobose with dark brown colour measuring 124.16 ?m × 2.35 ?m in average. The pycnidio spores were hyaline, oval to bullet shaped, monoguttulate measuring 4.02 ?m × 2.35 ?m in average. Among the different media tested for growth highest growth was recorded in Oat meal agar (26.44 cm2) followed by malt extract agar (24.04 cm2) which was statistically at par. The temperature of 25?C favoured maximum growth (24.20 cm2). However, higher sporulation was observed in 30?C. Among the different carbon source tested, mannitol supported the highest growth of the pathogen (27.67 cm2).