Cultural, Morphological and Pathogenic Characterization of Alternaria porri Causing Purple Blotch of Onion

  • Sayed Mohammad MOHSIN Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh
  • Md. Rafiqul ISLAM Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh
  • Abu Noman Faruq AHMMED Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh
  • Hosna Ara Chowdhury NISHA Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh
  • Mirza HASANUZZAMAN Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University

Abstract

Twenty seven (27) isolates of Alternaria porri were isolated from diseased leaf samples collected from different onion growing regions of Bangladesh and characterized for cultural, morphological and pathogenic variabilities. A. porri colonies colony colour ranged between light to dark olivacious and grayish white with irregular, regular with concentric ring and regular without concentric ring shape. Margin of colonies were entire, irregular and wavy with effuse, fluffy and velvety texture. Isolates impregnated media with colour ranged between grey to brown on the reverse of the plates. Growth rate of isolates ranged between 2.433 and 3.950 mm/day with fast growth in isolate DSTR 02 and least in MMBH. Morphological variation in conidia production was between 7.720×103 to 47.02×103 per mm2 with sporulation time 3.33 to 11.00 days. The conidial shape was straight to curve with light to deep brown colour. The number of horizontal and vertical separation in the conidia ranged from 3.00 to 6.00 × 1.00 to 2.00 with size from 11.20 to 39.20 × 4.76 to 11.43 µm. In pathogenicity test isolates also exhibited variations in size of the lesions (2.77 to 7.55 mm) produced on onion leaves. The results demonstrate existence of considerable variation in cultural, morphological, and pathogenic characters of A. porri isolates prevalent in Bangladesh environment.

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Published
2016-06-14
How to Cite
MOHSIN, S. M., ISLAM, M. R., AHMMED, A. N. F., NISHA, H. A. C., & HASANUZZAMAN, M. (2016). Cultural, Morphological and Pathogenic Characterization of Alternaria porri Causing Purple Blotch of Onion. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 44(1), 222-227. https://doi.org/10.15835/nbha44110110
Section
Research Articles