Journal of Plant Pathology Archive

Abstract:

Crinum latifolium, a bulbous herb of the family Amarylli- daceae, is greatly valued for traditional medicine in India (Beck- strom et al., 1994). During a post-rainy survey, leaves of C. latifoli- um showed symptoms characterized by scattered, small circular to irregular, brown to light-red lesions with a yellow halo. Old le- sions became shrunken and brick-red in the centre. The disease caused significant reduction in the weight and volume of the med- icinally valuable bulbs. Diseased tissue fragments were surface- sterilized and plated on PDA at 22±2°C for 7 days. A fungus pro- ducing greyish to blackish colonies with red pigmentation, which consistently isolated from diseased tissue, was identified as Drech- slera halodes (Drechsler) Subramanian et Jain using standard monographs and taxonomic keys (Ellis, 1971). Conidiophores were up to 200 μm long, 5-10 in μm thick, septate, cylindrical, brown and paler towards the apex. Conidia were straight to slight- ly curved, thick-walled, had a basal septum darker and thicker than the other septa and measured 15-170×5-25 μm. The identity was confirmed by the National Fungal Culture Collection of India (NFCCI), Agharkar Research Institute, Pune, India (Culture no. OP 75). To confirm pathogenicity, disease-free plants were inocu- lated with conidial suspensions containing 1000 conidia per ml. Controls were inoculated with sterile distilled water. After 1 week, leaf spots similar to those observed in the field were observed on inoculated but not on control plants. The pathogen was re-isolat- ed from inoculated leaves, fulfilling Koch’s postulates. To our knowledge, on the basis of the literature (Jamaluddin et al., 2004), this is the first report from India and worldwide of D. halodes in- fections causing leaf blight of C. latifolium.