DISEASE NOTE Journal of Plant Pathology https://doi.org/10.1007/s42161-022-01251-7 ITS MH879769, EndoPG MK168643, RPB2 ON568191, and GAPDH ON568192) showed 99–100% similarity with references LC440581, KP789546, and KP124767, and KP124156 respectively. Pathogenicity test was conducted on 50 healthy fruits, surface disinfected as reported above, sprayed with 10 5 conidia/mL suspension, and incubated at 26 ± 1 °C. Control fruit (n = 50) were sprayed with distilled water. Four days post-inoculation the fruits exhibited brown spot symptoms. ALT-16 was recovered from infected fruits and morphologically identifed. The strain was deposited at the Fungal Culture Collection, University of Agriculture, Faisalabad, Pakistan. Previously, we reported A. alternata causing postharvest brown spot of mandarin in Pakistan (Moosa et al. 2021; Liaquat et al. 2021) reported preharvest brown spot of lemon caused by A. alternata, using the 18S rRNA region for identifcation. However, to our knowledge, this is the frst record of A. alternata causing postharvest brown spot of lemon in Pakistan, identifed using a multi- locus approach. Funding Authors acknowledge the Deanship of Scientifc Research, King Khalid University, Saudi Arabia for funding this work under grant no. (R.G.P. 2/131/43). Declarations Ethical approval This article does not contain any studies with human participants or animals performed by any of the authors. Disclosure of potential conflict of interest The authors do not have any confict of interest. Informed consent Informed consent was obtained from all members involved in this research. In 2018, infected lemons (Citrus limon cv. ‘Meyer Lemon’) were collected from the fruit market of Faisalabad, Pakistan. The fruit had visible brown spots symptoms on the peel with 9% disease incidence. Fruit (n = 50) were collected and pro- cessed. To isolate the pathogen, fruit peel was excised into small 2 mm-segments. These segments were surface dis- infected with 1% NaOCl and rinsed with sterilized water. Then they were plated on Potato Dextrose Agar (PDA) and incubated at 26 ± 1 °C. Fungal colonies appeared irregular, olive-green at the margins and dark brown to blackish at the center. Conidia were ovoid to obclavate, 23.9 to 45.3 × 9.3 to 16.1 μm with 1–6 horizontal and 0–2 transverse septa, and with 8.9 μm beak. Based on morphology, pathogen was identifed as Alternaria alternata (Fr.) Keissl. The Internal Transcribed Spacer (ITS), endopolygalacturonase (EndoPG), RNA polymerase-II (RPB2), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) genes were ampli- fed for confrmation (Andrew et al. 2009). BLAST analyses of representative isolate ALT-16 (GenBank accession No.  Anam Moosa annu_77@Live.com 1 Department of Plant Pathology, The Islamia University of Bahawalpur, Bahawalpur, Pakistan 2 Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China 3 Department of Biology, Faculty of Science, King Khalid University, Abha, Saudi Arabia 4 Department of Botany and Microbiology, Faculty of Science, South Valley University, Qena, Egypt 5 Department of Pathology, College of Medicine, King Khalid University, Abha, Kingdom of Saudi Arabia 6 Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura, Egypt Keywords Meyer lemon · Pathogenicity · Morphology · Fruit · Alternaria alternata Received: 23 May 2022 / Accepted: 16 October 2022 © The Author(s) under exclusive licence to Società Italiana di Patologia Vegetale (S.I.Pa.V.) 2022 First report of post-harvest brown spot of lemon caused by Alternaria alternata in Pakistan Anam Moosa 1  · Muhammad Naveed Aslam 1  · Muhammad Taimoor Shakeel 1  · Tanvir Ahmad 2  · Mahmoud Moustafa 3,4  · Mohammed Al-Shehri 3  · Ahmed Al-Emam 5,6 1 3