FIRST REPORT OF LEAF SPOT DISEASE OF CALOTROPIS GIGANTEA CAUSED BY PASSALORA CALOTROPIDISIN LAHORE, PAKISTAN

I. Mukhtar, I. Khokhar and S. Mushtaq

First Fungal Culture Bank of Pakistan (FCBP), Institute of Agriculture Sciences, University of the Punjab, Lahore, Pakistan
Corresponding author e-mail: erumm21@yahoo.com

ABSTRACT

Aak [Calotropis gigantea (L.) R. Br. ex. Ait.] leaf and stem samples infected by leaf spot were collected during August and September 2011 from Lahore Pakistan .  Infected leaf and stem surfaces were covered with circular to irregular blackish spots. Conidiophores 15-50 × 4-6 x µm, arising from substomatal stroma in loose fascicles of 8 -15, pale to light golden yellow, simple, sometimes geniculate near tip, 0-3 transversely septate. Conidia solitary, thin and smooth walled, cylindric to cylindro-obclavate, 0-8 septate, obconic base, subobtuse to bluntly rounded tip, 10-130 × 4-6 µm. Morphological characteristics and  pathogenecity test confirmed the identification as Passalora calotropidis . However, this is the first report of P. calotropidis on Calotropis gigantea from Pakistan.
Key words: leaf spot, Calotropus, Pakistan, Passalora calotropidis.