Isolation and Morphological Characterization of Aspergillus flavus and Fusarium moniliforme in Groundnut: Implications for Aflatoxin Contamination in Pakistan

Abstract

Groundnut (Arachis hypogea L), also known as peanut, is a significant oilseed crop in the world that has some important nutrients such as carbohydrates, fats, proteins, vitamins, and minerals. Nonetheless, post-harvesting in tropical areas suffers a massive setback due to the presence of mycotoxins, mainly aflatoxins, which are toxic and are produced by fungi, including Aspergillus spp., Penicillium spp., and Fusarium spp. Such toxins are dangerous to the health of human beings and animals, and have significant market access consequences. This paper examines the occurrence of mycotoxins in groundnut crops in two areas of Pakistan: Koont farm, Chakwal, and Attock, during the 2018-2019 growing season. The study aimed to isolate, identify, and characterize fungal pathogens associated with groundnut seeds. Four groundnut varieties (BARI-2000, BARI-2011, BARI-2016 and Mirza Sanjwal Bora 334) were used in collecting 400 samples of seed (40 samples each) randomly and systematically. The Moisture Content was also determined to have a considerable variation in different varieties. BARI-2016 had only 21 per cent Moisture Content, but after one-month air-drying, it had dropped to 10 per cent in Mirza Sanjwal Bora 334. Fungal growth was identified on BARI-2000, BARI-2011, and BARI-2016 through a seed-borne mycoflora study. The fungi found to enter are Aspergillus flavus and Fusarium moniliforme, which are the primary contaminants. Silica gel was used in the purification and preservation of fungal isolates, and morphologic analysis was done using lactophenol blue stains on cotton. The findings showed fungal contamination in the BARI-2000 and BARI-2011 varieties to be more than that of the other two varieties. This paper highlights the need for improved practices in handling and storing crops after harvest to reduce the risk of aflatoxin contamination in groundnut crops, particularly in areas prone to fungal infestation.

Keywords: Aflatoxins analysis, Fusarium isolation, Peanut microbiology, Mycotoxins effects, Food Contamination