Molecular Characterization of Post Harvest Fungus Associated with Spoilt Broccoli

Abstract

Broccoli (Brassica oleracea var. italica) is a nutritional vegetable that looks like a small tree. Despite the fact that it is extensively loaded with arrays of vitamins, minerals, fiber and antioxidants, it has been observed that it has a short lifespan of not more than 2-5 days due to post-harvest deterioration. A study was conducted to isolate and identify the common fungal pathogens causing post-harvest deterioration of broccoli crown. Diseased broccoli crowns were collected from Ogunabali Fruit Garden Market in D-Line, Port Harcourt Local Government Area of Rivers State. Fungal isolates were collected and morphologically identified. The DNA of the most common fungal isolate, BC-3B was molecularly characterized using Internal Transcribed Spacer 4 and 5 (ITS-4 and 5) molecular markers. The morphological studies revealed that the BC-3B isolate was an Aspergillus niger. The BC-3B isolate DNA sequence was aligned using Basic Local Alignment Search Tool for Nucleotide (BLASTN) 2.8.0 version of National Center for Biotechnology Information (NCBI) database. The molecular weight of the DNA of the isolates was over 600base pairs. Based on sequence similarity, it was observed that the broccoli isolate BC-3B was 93% identical to Aspergillus niger. From the above results, these findings showed that Aspergillus niger is the causal fungal pathogen of post-harvest rot of broccoli. Phylogenetic tree was constructed to access the relationship between the isolates obtained from this study. This study has provided information on some of the fungal organisms found in broccoli. It is anticipated that this result will provide information for disease control approach for alleviating the post-harvest losses of broccoli caused by Aspergillus niger and provide a foundation for further study of possible harm of consuming diseased broccoli.