Cultural, morphological, pathogenic and molecular characterization of Alternaria mali associated with Alternaria leaf blotch of apple

  • TA Sofi
  • Muzafer A Beig
  • Gh. Hassan Dar
  • Mushtaq Ahmad
  • Aflaq Hamid
  • FA Ahangar
  • BA Padder
  • MD Shah

Abstract

Alternaria blotch (Alternaria mali) causes severe foliar damage to apple trees in Kashmir. Twenty one (21) isolates of A. mali were collected from different locations and characterized for cultural, morphological, pathogenic and molecular variations. A. mali colonies varied in their cultural behaviour ranging from velvety to cottony, mostly appressed, with regular to irregular margins. Colour of colonies ranged between light to dark olivacious. Isolates impregnated media with colour ranging between grey to brown. Growth rate of isolates was between 5.86 to 8.21 mm/day with fast growth in isolate Am-13 and least in Am-5. Morphological variations in size, shape and septation of hyphae, conidiophore and conidia were observed in the isolates with significant variations in conidiophore and conidial septation. Average conidial size ranged from 21.36 to 31.74 x 8.34 to 14.48 μm. Isolates exhibited variations in incubation period, number and size of the lesions were produced. The dendrogram analysis, based on cultural, morphological and pathogenic studies, revealed variation within A. mali population. At 67% similarity matrix, all the isolates formed 2 clusters with 12 and nine isolates in cluster I and II, respectively. However, dendrogram on molecular (random amplification of polymorphic DNA, RAPD) basis revealed five clusters at 68% Dice similarity coefficient. There was no congruence between RAPD pattern and cultural, morphological and pathogenic characters. Isolates identical for one spectrum were often dissimilar for other spectrum. The results demonstrate existence of considerable variation in cultural, morphological, pathogenic and molecular characters of A. mali isolates prevalent in Kashmir valley.

Keywords: Apple, Alternaria mali, variability, cultural, morphological, pathogenic, RAPD

African Journal of Biotechnology Vol. 12(4), pp. 370-381

Author Biographies

TA Sofi
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
Muzafer A Beig
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
Gh. Hassan Dar
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
Mushtaq Ahmad
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
Aflaq Hamid
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
FA Ahangar
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
BA Padder
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
MD Shah
Division of Plant Pathology, SKUAST- Kashmir, Shalimar, Srinagar-191121, Jammu and Kashmir, India
Published
2015-11-29
Section
Articles

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