Evaluation of the rust fungus Puccinia rapipes for biological control of Lycium ferocissimum (African boxthorn) in Australia: life cycle, taxonomy and pathogenicity

Publication date: Available online 21 August 2019Source: Fungal BiologyAuthor(s): Kylie B. Ireland, Gavin C. Hunter, Alan Wood, Caroline Delaisse, Louise MorinAbstractFungal plant pathogens are increasingly recognised as being among the most effective and safe agents in classical weed biological control programs worldwide. Suitability of the rust fungus Puccinia rapipes as a classical biological control agent for Lycium ferocissimum (African boxthorn) in Australia was assessed using a streamlined agent selection framework. Studies with P. rapipes were undertaken to elucidate its life cycle, confirm its taxonomic placement and determine its pathogenicity to L. ferocissimum and seven closely-related Solanaceae species that occur in Australia. Field surveys in the native range of South Africa, experiments in a containment facility in Australia and DNA sequencing confirmed that P. rapipes is macrocyclic and autoecious, producing all five spore stages on L. ferocissimum. The stages not previously encountered, spermogonia and aecia, are described. Sequencing also confirmed that P. rapipes is sister to Puccinia afra, in the ‘Old World Lineage’ of Puccinia species on Lycieae. Two purified isolates of the fungus, representing the Eastern and Western Cape distributions of P. rapipes in South Africa, were cultured in the containment facility for use in pathogenicity testing. Lycium ferocissimum and all of the Lycium species of Eurasian origin tested ‒ L. barbarum (goji berry), L. ...
Source: Fungal Biology - Category: Biology Source Type: research