Davy Moussango Victor, Steve Voundi Olugu, Sammuel Tchabong Raymond, Boat Marie Ampères Bedine, Moise Ntah Ayong, Busuioc Anna Cazanevscaia, Mbondi Priscile Ebong, Botezatu Andreea Veronica Dediu, Jules Manz Koule, Mihaila Maria Daniela Ionica, Dinica Rodica Mihaela, Lambert Sameza Modeste
Biotechnologies Laboratory, University Institute of Technology, University of Douala, Douala 8698, Cameroon.
Laboratory of Biochemistry, Faculty of Science, University of Douala, Douala 24157, Cameroon.
J Fungi (Basel). 2025 May 17;11(5):385. doi: 10.3390/jof11050385.
Post-harvest decay of L. is the primary cause of deterioration in papaya quality and the low economic impact of this sector in Cameroon. Field surveys conducted by teams from the Ministry of Agriculture and Rural Development (MINADER) in Cameroon have primarily associated these decays with fungal attacks. However, to date, no methodological analysis has been conducted on the identification of these fungal agents. To reduce post-harvest losses, rapid detection of diseases is crucial for the application of effective management strategies. This study sought to identify the fungal agents associated with post-harvest decay of papaya Sunrise solo in Cameroon and to determine their physiological and biochemical growth characteristics. Isolation and pathogenicity tests were performed according to Koch's postulate. Molecular identification of isolates was achieved by amplification and sequencing of the ITS1 and ITS4 regions. Phylogenetic analysis was based on the substitution models corresponding to each fungal genus determined by jModeltest, according to the Akaike information criterion (AIC). Fungal explants of each identified species were subjected to variations in temperature, pH, water activity, and NaCl concentration. The ability to secrete hydrolytic enzymes was determined on specific media such as skimmed milk agar for protease, peptone agar for lipase, and carboxymethylcellulose for cellulase. These experiments allowed the identification of three fungi responsible for papaya fruit decay, namely , , and . All three pathogens had maximum mycelial growth at a temperature of 25 ± 2 °C, pH 6.5, NaCl concentration of 100 µM, and water activity (aw) equal to 0.98. The three fungal agents demonstrated a strong potential for secreting cellulases, lipases, and proteases, which they use as lytic enzymes to degrade papaya tissues. The relative enzymatic activity varied depending on the fungal pathogen as well as the type of enzyme secreted. This study is the first report of as a causal agent of papaya fruit decay in Cameroon.
番木瓜采后腐烂是喀麦隆番木瓜品质下降以及该产业经济影响较低的主要原因。喀麦隆农业和农村发展部（MINADER）的团队进行的实地调查主要将这些腐烂与真菌侵袭联系起来。然而，迄今为止，尚未对这些真菌病原体的鉴定进行方法学分析。为减少采后损失，快速检测病害对于应用有效的管理策略至关重要。本研究旨在鉴定喀麦隆日出单果番木瓜采后腐烂相关的真菌病原体，并确定其生理生化生长特性。根据科赫法则进行分离和致病性测试。通过ITS1和ITS4区域的扩增和测序实现分离株的分子鉴定。系统发育分析基于jModeltest根据赤池信息准则（AIC）确定的每个真菌属对应的替代模型。对每个鉴定出的物种的真菌外植体进行温度、pH、水分活度和NaCl浓度的变化处理。在特定培养基上测定分泌水解酶的能力，如用于蛋白酶的脱脂牛奶琼脂、用于脂肪酶的蛋白胨琼脂和用于纤维素酶的羧甲基纤维素。这些实验鉴定出三种导致番木瓜果实腐烂的真菌，即 、 和 。所有三种病原体在温度25±2°C、pH 6.5、NaCl浓度100µM和水分活度（aw）等于0.98时菌丝体生长最快。这三种真菌病原体表现出很强的分泌纤维素酶、脂肪酶和蛋白酶的潜力，它们将这些酶用作裂解酶来降解番木瓜组织。相对酶活性因真菌病原体以及分泌的酶的类型而异。本研究是喀麦隆首次报道 作为番木瓜果实腐烂的病原体。
