Variation in susceptibility of Banksia (including Dryandra) to Phytophthora cinnamomi

• Published in: Australasian plant pathology Vol. 42; no. 3; pp. 351 - 361
• Main Authors: Shearer, B. L., Crane, C. E., Cochrane, J. A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.05.2013; Springer Nature B.V
• Subjects: Agriculture; Biomedical and Life Sciences; Ecology; Entomology; Life Sciences; Plant Pathology; Plant Sciences; Mortality; Rate; Declared rare flora; Asymptote; Evolution resistance; Delay; Resistance mechanisms; Botanical epidemiology; Lag; Fortuitous side effect; Intra-specific variation; Logistic model parameters; Disease progress curves; Susceptibility continuum
• ISSN: 0815-3191; 1448-6032
• DOI: 10.1007/s13313-012-0189-4

Variation in susceptibility of 109 Western Australian Banksia and Dryandra and 16 Eastern Australian Banksia to Phytophthora cinnamomi infection was evaluated after soil inoculation. Banksia and Dryandra were initially analysed separately and then combined due to the transfer of Dryandra to Banksia . Disease progress curves of % mortality following soil inoculation were analysed with the three logistic model parameters of upper asymptote (K max ), lag time (t ½K ) and intrinsic rate of increase (r). The susceptibility continuum represented by the ordination of parameters of the logistic model for % plant mortality in two dimensions was similar for Banksia , Dryandra and combined Banksia and Dryandra . Although resistant taxa had low K max , the values for delay and rate varied. In comparison, susceptible taxa tended to have high K max short delay and fast rate. Western Australian threatened and priority Banksia were significantly more susceptible than common Banksia . Seeders were more susceptible than resprouters. There was no significant difference in Western Australian Banksia susceptibility between soil, rainfall region, bioregion and growth form. Of the Western Australian Banksia tested, 40 % were most at risk of P . cinnamomi infection because they were either threatened, priority or common though geographically restricted taxa with K max of mortality >50 %. Positioning Banksia taxa on the P . cinnamomi resistance-susceptibility continuum needs to be incorporated into extinction-risk methodology in order to prioritise flora for conservation actions according to hazard from the pathogen.