Abida Akram

Mycoflora Detected from Seeds of Sesamum indicum L. in Sialkot, Pakistan

Sesame seeds (Sesamum indicum L.) from various localities of Sialkot were analysed for their mycoflora by using Agar plate, Blotter paper and Deep freezing method. Agar plate and Deep freezing method yielded 22 and 21 fungal species respectively followed by Blotter paper method yielded 19 species. A total number of 36 species belonging to 10 genera of fungi were isolated. The prevalent genera were Penicillium (10 species), Alternaria (7 species), Fusarium (5 species), Cercospora and Cladosporium (4 species each). Penicillium was predominant followed by Alternaria and Fusarium. All detected fungi are the first record of mycolflora from sesame seeds in Sialkot, Pakistan.

The Incidence of Alternaria Species Associated with Infected Sesamum indicum L. Seeds from Fields of the Punjab, Pakistan

Sesame (Sesamum indicum) is an important oil seed crop of Asia. Yields can be negatively impacted by various factors, including disease, particularly those caused by fungi which create problems in both production and storage. Foliar diseases of sesame such as Alternaria leaf blight may cause significant yield losses, with reductions in plant health and seed quality. The work reported here determined the incidence of Alternaria species infecting sesame seeds grown in the Punjab, Pakistan. A total of 428 Alternaria isolates were obtained from 105 seed samples and grouped into 36 distinct taxonomic groups based on growth pattern and morphological characters. Isolation frequency and relative density of surface sterilized and non-surface sterilized seeds showed that three isolates (A13, A47 and A215) were the most common morphological groups present. These isolates were further identified using sequencing of the Internal Transcribed Spacer (ITS) region of ribosomal DNA (rDNA) and the Alternaria major allergen gene (Alt a 1). Whilst ITS of rDNA did not resolve the isolates into Alternaria species, the Alt a 1 sequences exhibited > 99% homology with Alternaria alternata (KP123850.1) in GenBank accessions. The pathogenicity and virulence of these isolates of Alternaria alternata was confirmed in inoculations of sesame plants resulting in typical symptoms of leaf blight disease. This work confirms the identity of a major source of sesame leaf blight in Pakistan which will aid in formulating effective disease management strategies.

Short Communication: Seed Viability Test and Pathogenecity Assessment of Most Prevalent Fungi Infecting Sesamum indicum L.

Sesame is an important source of oil and protein. The quality of sesame crop is adversely affected by various fungal diseases, which not only reduce its production but also affects its export in various countries. During the mycological analysis of sesame seeds in our previous report, a total number of 36 species belonging to 10 genera of fungi were isolated. The prevalent genera were Alternaria, Aspergillus, Cercospora, Fusarium, Penicillium and Rhizopus. The present study aimed to test the seed viability and pathogenecity of the predominant fungi infecting sesame in region of Sialkot, Pakistan. Results indicated that the germination rate was increased and seed borne fungi were eliminated with seed sterilization. The pathogenecity of isolates was evaluated at seedling stage which confirmed the incidence of prevalent fungi. Plant growth was significantly decreased in inoculated plants as compared to un-inoculated plants. Deleterious effects on roots were observed which ultimately affected the whole seedlings. Therefore, we may conclude that fungal test species used in this study are virulent pathogens of sesame which can be controlled by different seed treatments before sowing.