Multiple Gene Sequences Delimit Botryosphaeria australis sp. nov. from B. lutea

Abstract

Botryosphaeria lutea (anamorph Fusicoccum luteum) most easily is distinguished from other Botryosphaeria spp. by a yellow pigment that is formed in young cultures. This fungus has been reported from a number of cultivated hosts in New Zealand and Portugal. During a survey of Botryosphaeria fungi that occur on native Acacia species in Australia, a yellow pigment was observed in some cultures. These isolates were morphologically similar to B. lutea, but the pigment differed slightly from the one formed by authentic B. lutea isolates. Preliminary data also revealed small differences in ITS rDNA sequence data. The aim of this study was to determine whether these small differences were indicative of separate species or merely variations within B. lutea. Anamorph, teleomorph and culture morphology were compared between B. lutea and Acacia isolates from Australia. Sequence data of two other genome regions, namely the ␤-tubulin and EF1-␣ gene and intron regions, were combined with ITS rDNA sequence data to determine the phylogenetic relationship between these isolates. Isolates of B. lutea and those from Australian Acacia species were not significantly different in spore morphology. The yellow pigment, however, was much more distinct in cultures of B. lutea than in cultures from Acacia. There were only a few base pair variations in each of the analyzed gene regions, but these variations were fixed in the two groups in all regions. By combining these data it was clear that B. lutea and the isolates from Acacia were distinct species, albeit very closely related. We, therefore, propose the new epithet B. australis for the fungus from Australia. Botryosphaeria australis also was isolated in this study from exotic Sequoiadendron trees in Australia. Re-analyses of GenBank data in this study showed that B. australis also occurs on other native Australian hosts, namely a Banksia sp. and a Eucalyptus sp., as well as a native Protea sp. in South Africa and on Pistachio in Italy. These records from GenBank have been identified previously as B. lutea. The common occurrence of B. australis on a variety of native hosts across Australia suggests that this fungus is native to this area.

Prevalence and distribution of Botryosphaeriaceae species in New Zealand grapevine nurseries

“…The similarities between N. australe and N. luteum observed in this study were also reported by Slippers et al (2004a) and Amponsah et al (2011), who also reported great variation between N. parvum isolates, since colony pigmentation on PDA plates was pale yellow, cream or white. However, the morphological characteristics did allow grouping of many isolates in presumptive species which were confirmed with ARDRA, and DNA sequencing of rDNA in this study.…”

Diversity and significance of fungal endophytes from living stems of naturalized trees from Argentina

“…Note the central hole (arrow). Bars: 3, 5-9,12=10 µm; 1, 2, 4, 10, 11, 13,14=5 µm yellow pigment in culture (Slippers et al 2004) that was not observed in our strains. In addition, the overlapping of conidial size within this genus (Slippers and Wingfield 2007) compels us to be cautious before considering the presence of Neofusicoccum australe in Argentina.…”

Survey of Botryosphaeriaceae associated with grapevine decline in the Hunter Valley and Mudgee grape growing regions of New South Wales

“…Ascospores, although rarely observed, were hyaline, aseptate, fusoid to ovoid. The second group was characterised by the production of a yellow pigment after two to three days on PDA, a defining characteristic of both N. australe and N. luteum (Witcher and Clayton 1963, Pennycook and Samuels 1985, Slippers et al 2004b, with later abundant white fluffy aerial mycelia. The culture eventually turned dark grey to black.…”