First report of Alternaria alternata and Alternaria jacinthicola causing black spot on pear (Pyrus communis) in northeastern Brazil

Pear ( Pyrus spp.) is one of the most widely consumed fruits in Brazil and is cultivated across 14 regions of the country. In northeastern Brazil, pear production has recently expanded, and concomitantly, diseases have been increasingly observed, including Alternaria black spot, whose etiology and species diversity remain unknown in the country. In this study, Alternaria isolates obtained from pear leaves and fruits were characterized using morphological features and multilocus phylogenetic analyses based on partial nucleotide sequences of the ITS region and the Alt a1 , tef1 , rpb2 , and gapdh genes. A total of 12 isolates were analyzed, and phylogenetic inference grouped them into two well-supported clades corresponding to Alternaria alternata and Alternaria jacinthicola . Pathogenicity assays on pear seedlings and fruits confirmed that all isolates were able to induce typical black spot symptoms. Based on combined morphological and molecular evidence, these two species were identified as the causal agents of Alternaria black spot on pear cultivated in northeastern Brazil. This study represents the first investigation of the etiology of this disease in Brazil and the first report of A. jacinthicola associated with black spot on pear worldwide. • Alternaria black spot was detected on Pyrus spp. in pear-producing areas of Pernambuco, Alagoas, and Sergipe, Brazil. • Pathogenicity assays confirmed Alternaria alternata and A. jacinthicola as the causal agents of Alternaria black spot. • This study provides the first report of Alternaria black spot on Pyrus spp. caused by A. alternata in Brazil and by A. jacinthicola worldwide.