Seerat Wajiha, Akram Abida, Qureshi Rahmatullah, Yaseen Ghulam, Mukhtar Tariq, Hanif Nafeesa Qudsia
Department of Botany, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan.
Department of Botany, Division of Science and Technology, Township campus, University of Education, Lahore, Pakistan.
Microsc Res Tech. 2022 Aug;85(8):2894-2903. doi: 10.1002/jemt.24139. Epub 2022 May 9.
Maize (Zea mays L.) is considered as one of the main cereals, used as a source of food, forage, and processed products. The loss of maize productivity is reported due to effect on roots, stalks, ears, and kernels mainly caused by many fungi. Among these fungal pathogens of maize, Aspergillus flavus (A. flavus) are the most prevalent that produces highly toxigenic aflatoxins that are highly carcinogenic to the consumers. The present study is confined to isolate and characterize the A. flavus from maize seeds for accurate identification that can be helpful for determination and management of aflatoxins in maize crop. Eighty stored seed samples of maize were collected from warehouses where seeds are stored for food and feeding purposes. For the isolation of A. flavus, Potato Dextrose Agar was used. Isolated fungi were identified macro and microscopically using light microscope and scanning electron microscope. A total of 212 Aspergillus isolates were identified based on macro-morphological and micro-morphological characteristics. The results showed that A. flavus colonies were granular, flat with yellow-green to deep yellow-green colony color having a white border and compact, spherical spore heads. Rapid rate of growth was observed maturing in about 3-5 days. In microscopic features, A. flavus have apically swollen conidiophores with various conidia bearing cells in long and dry chains. Spherical conidial heads were split into several columns ranging 300-400 μm in diameter. This will be helpful for farmers, researchers and traders in future for correct identification of sources of aflatoxins. RESEARCH HIGHLIGHTS: Maize seed samples were collected from Pothohar region of Pakistan. The fungi were isolated on PDA. Aspergillus flavus was identified macro-morphologically by observing growth rate, colony color and texture. Furthermore, these fungi were identified micro-morphologically by using light and scanning electron microscope. The 212 Aspergillus flavus strains were isolated and identified.
玉米（Zea mays L.）被视为主要谷物之一，用作食物、饲料和加工产品的来源。据报道，玉米生产力的损失是由于许多真菌主要对根、茎、穗和籽粒造成影响所致。在这些玉米真菌病原体中，黄曲霉（A. flavus）最为普遍，它会产生对消费者具有高度致癌性的高毒性黄曲霉毒素。本研究局限于从玉米种子中分离和鉴定黄曲霉，以便进行准确识别，这有助于测定和管理玉米作物中的黄曲霉毒素。从用于食品和饲料用途的种子储存仓库中收集了80份储存的玉米种子样本。为了分离黄曲霉，使用了马铃薯葡萄糖琼脂。使用光学显微镜和扫描电子显微镜对分离出的真菌进行宏观和微观鉴定。根据宏观形态和微观形态特征，共鉴定出212株曲霉菌株。结果表明，黄曲霉菌落呈颗粒状，扁平，菌落颜色为黄绿至深黄绿色，有白色边缘，孢子头紧密、球形。观察到生长速度较快，约3 - 5天成熟。在微观特征方面，黄曲霉的分生孢子梗顶端肿胀，有各种产孢细胞，呈长而干燥的链状。球形分生孢子头分成几列，直径在300 - 400μm之间。这将有助于未来农民、研究人员和贸易商正确识别黄曲霉毒素的来源。研究亮点：从巴基斯坦波托哈尔地区收集了玉米种子样本。在马铃薯葡萄糖琼脂上分离真菌。通过观察生长速度、菌落颜色和质地对黄曲霉进行宏观形态鉴定。此外，使用光学显微镜和扫描电子显微镜对这些真菌进行微观形态鉴定。分离并鉴定了212株黄曲霉菌株。
