Pseudocercospora and allied genera associated with leaf spots of banana (Musa spp.)

Abstract

The Sigatoka leaf spot complex on Musa spp. includes three major pathogens: Pseudocercospora, namely P. musae (Sigatoka leaf spot or yellow Sigatoka), P. eumusae (eumusae leaf spot disease), and P. fijiensis (black leaf streak disease or black Sigatoka). However, more than 30 species of Mycosphaerellaceae have been associated with Sigatoka leaf spots of banana, and previous reports of P. musae and P. eumusae need to be re-evaluated in light of recently described species. The aim of the present study was thus to investigate a global set of 228 isolates of P. musae, P. eumusae and close relatives on banana using multigene DNA sequence data [internal transcribed spacer regions with intervening 5.8S nrRNA gene (ITS), RNA polymerase II second largest subunit gene (rpb2), translation elongation factor 1-alpha gene (tef1), beta-tubulin gene (tub2), and the actin gene (act)] to confirm if these isolates represent P. musae, or a closely allied species. Based on these data one new species is described, namely P. pseudomusae, which is associated with leaf spot symptoms resembling those of P. musae on Musa in Indonesia. Furthermore, P. eumusae, P. musae and P. fijiensis are shown to be well defined taxa, with some isolates also representing P. longispora. Other genera encountered in the dataset are species of Zasmidium (Taiwan leaf speckle), Metulocladosporiella (Cladosporium leaf speckle) and Scolecobasidium leaf speckle.

A chromosome-level genome assembly ofZasmidium syzygiiisolated from banana leaves

“…We obtained a highly similar match (98.7% nucleotide identity) to Zasmidium syzygii (NR_111826.1), supporting that the assembled isolate belongs to the Zasmidium genus. In line with this finding, previous studies have found Zasmidium isolates on symptomatic banana leaves (Arzanlou et al, 2008;Crous et al, 2021), and other Zasmidium species are reported to cause leaf spot diseases on other plant species such as citrus (Aguilera-Cogley et al, 2017;An et al, 2021;Han et al, 2015). The Zasmidium genome assembly we report here is less fragmented and 4 Mb larger than the previous genome assembly of a Zasmidium species; Z. cellare.…”

“…Mycosphaerella strains obtained from banana leaves (Crous et al, 2021). A maximum-likelihood phylogeny based on the aligned ITS sequences confirmed that isolates P121 -P124 belong to the Zasmidium genus and shows that these four isolates encode identical ITS sequences (Figure 3).…”

“…Whole-genome alignments of our assembly to the P. fijiensis reference genome assembly revealed that none of the contigs display significant similarity (Figure S2). Therefore, we considered that the difference in genome size between isolates P121 -P124 and the P. fijiensis reference isolate P78 is likely caused by the isolation of a different fungal species associated with necrotic symptoms on banana foliage (Crous et al, 2021), most likely by a member of genus Zasmidium. ,11,13,15,and 16.…”

“…However, besides these three Pseudocercospora species, other fungal species can appear in association with symptomatic banana foliage. For example, a recent study that analysed fungal isolates associated with banana foliar diseases revealed the presence of over 30 other fungal species, primarily belonging to the Mycosphaerellacea family (Crous et al, 2021).…”

Exogenous and Endophytic Fungal Communities of Dendrobium nobile Lindl. across Different Habitats and Their Enhancement of Host Plants’ Dendrobine Content and Biomass Accumulation

“…Significant differences in community structure were observed between fungi from different habitats, although several common fungal genera were identified across habitats, including the endophytic genera Pseudocercospora and Apiotrichum and the exogenous genus Devriesia. Pseudocercospora is reported to cause leaf spot disease in banana, Ixora coccinea, and other plants, 32,33 although this is the first study to report this species as an endophyte. Apiotrichum melanogenum has been shown to benefit plant growth through the production of ammonia and indole-3-acetic acid (IAA).…”