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Cultural and morpho-molecular characterization of Fusarium solani and Alternaria spp. associated with fruit rot of strawberry

Nasir Mehmood: PMAS-Arid Agriculture University, Rawalpindi

<div>In Pakistan, Strawberry is emerging as commercial fruit crop with good economic returns. During 2014-15 and 2015-16 survey was conducted in important strawberry growing areas of Punjab, Khyber Pukhtunkhwa and Islamabad, Pakistan. Maximum mean disease incidence of 56% <em>fusarium</em> fruit rot (<em>Fusarium solani</em>) and 8% of <em>Alternaria</em> fruit rot (<em>Alternaria alternata</em> & <em>Alternaria tenuissima</em>) was recorded respectively. Fusarium fruit rot was observed as thick, white fluffy masses of mycelium while <em>Alternaria</em> fruit rot was characterized as small, brown to black, irregular lesions. Pure cultures of fungi were obtained from symptomatic fruit sections and subsequently identified on morphological and molecular bases. Seventy nine isolates of <em>F. solani</em> and 19 isolates of <em>Alternaria</em> spp. (13 of <em>A.</em> <em>tenuissima & </em>6 of <em>A. alternata)</em> were undergone for identification and variation in cultural, pathogenic and morphological features. Significant genetic variability was seen among isolates belonging to different geographical regions. Nucleotide sequences of 11 highly pathogenic isolates of <em>F. solani</em> and 7 of <em>Alternaria</em> spp. were amplified with transcribed spacer region (ITS), translation elongation factor 1- alpha (TEF1-α) and Endo-polygalacturonase gene regions (<em>Endo-PG</em>) and submitted in the GenBank. Evolutionary history was analyzed with available sequences of <em>F. solani</em> and <em>Alternaria</em> spp. Evolutionary trees were constructed by MEGA 7.0 using maximum likelihood method having isolates falling under different sub-trees due to genetic variation in nucleotides. Cultural, morphological, pathogenic and molecular characterization of pathogens associated with fruit rot of strawberry was first time recorded in Pakistan.</div>