Abstract
Lantana camara is a flowering shrub of the family Verbenaceae, native to the Americas which has become a major invasive weed in the Palaeotropics; affecting both natural and agricultural ecosystems. It has been the focus of classical biological control for over a century but has proven to be a problematic target because of its high genetic diversity. Here, we report on an aggressive pathotype of the microcyclic rust Puccinia lantanae collected in the Amazonian rainforest, which – based on greenhouse screening – is damaging to a wide range of biotypes of the L. camara complex. Host-range testing within the Verbenaceae and related plant families, involving leaf clearing and staining, showed the pathotype to be highly specific to L. camara sensu lato but with detectable symptoms in several other verbenaceous species. These results, together with a taxonomic re-appraisal of Puccinia lantanae, are discussed in relation to the potential of the rust as a classical biological control agent of L. camara. We conclude that this pathotype of P. lantanae is a valuable addition to the biological control armoury and posit that it should be especially successful in humid forest situations.
Highlights
Lantana camara L. (Verbenaceae) is a neotropical woody shrub with attractive flowers which has a pantropical distribution due to its horticultural value and ornamental interest
Based on previous experience with embedded microcyclic rusts – which showed that dried material quickly loses viability, with teliospores failing to germinate (Evans and Ellison, 2005) – bare-rooted infected seedlings were collected for pathogenicity studies
The results of the host-specificity testing detailed in this study show that only L. camara sensu lato is fully susceptible to P. lantanae isolate IMI 398849; whilst three related test species were found to be weakly or moderately susceptible to the rust: V. officinalis, Lippia alba and Phyla canescens
Summary
Lantana camara L. (Verbenaceae) is a neotropical woody shrub with attractive flowers which has a pantropical distribution due to its horticultural value and ornamental interest. P. lantanae pathotype (IMI 398849) is currently being considered for South Africa: encouragingly, the indigenous species Lantana rugosa Thunberg, as well as three Lippia species, were rated as resistant to the rust in preliminary tests (Seier et al, 2013) These examples provide circumstantial evidence that non-natural hosts are not at risk in the field. There would be limited genetic variation within indi vidual lineages, and this supports the hypothesis that a number of formae speciales (pathotypes), or varieties, exist within the P. lantanae complex – possibly similar to the P. xanthii complex (Seier et al, 2009) – suggesting that the opportunity for genetic variability with an individual ‘clone’ of P. lantanae is likely to be limited to mutation This restricts the likelihood of the rust increasing its virulence towards the nonnatural host V. officinalis, in the unlikely event that it does infect this species in the field
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
