Open AccessNeocosmospora spp. associated with dry root rot of citrus in South Africa
Author(s) -
Vladimiro Guarnaccia,
Jan van Niekerk,
Pedro W. Crous,
Marcelo Sandoval-Denis
Publication year - 2021
Publication title -
phytopathologia mediterranea
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.493
H-Index - 46
eISSN - 1593-2095
pISSN - 0031-9465
DOI - 10.36253/phyto-12183
Subject(s) - biology , internal transcribed spacer , root rot , botany , horticulture , intergenic region , ribosomal rna , biochemistry , gene , genome
Citrus is one of the most important fruit crops cultivated in South Africa. Internationally, citrus dry root rot is a common disease in major citrus production areas. Several abiotic and biotic factors are involved in disease development, in which Neocosmospora species are important biotic agents. The diversity of Neocosmospora species associated with dry root rot symptoms of Citrus trees cultivated in South Africa was evaluated using morphological and molecular analyses. Multi-locus analysis was conducted, based on fragments of seven loci including: ATP citrate lyase (acl1), calmodulin (cal), internal transcribed spacer region of the rRNA (ITS), large subunit of the rRNA (LSU), RNA polymerase largest subunit (rpb1), RNA polymerase second largest subunit (rpb2), and translation elongation factor 1-alpha (tef1). A total of 62 strains representing 11 Neocosmospora species were isolated from crowns, trunks and roots of citrus trees affected by dry root rot, as well as from soils sampled in affected citrus orchards. The most commonly isolated taxa were N. citricola, N. ferruginea and N. solani, while rarely encountered taxa included N. brevis, N. crassa, N. hypothenemi and N. noneumartii. Furthermore, four Neocosmospora species are also newly described, namely N. addoensis, N. citricola, N. gamtoosensis and N. lerouxii.