Genetic, morphological and pathogenic diversity in the canker pathogen Cryptodiaporthe melanocraspeda on Banksia

• Published in: Australasian plant pathology Vol. 44; no. 3; pp. 299 - 309
• Main Authors: Shearer, B. L., Crane, C. E.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.05.2015; Springer Nature B.V
• Subjects: Agriculture; Biomedical and Life Sciences; Breeding; Canker; Ecology; Entomology; Genetic distance; Genetic diversity; Lesions; Life Sciences; Original Paper; Pathogens; Plant diversity; Plant Pathology; Plant Sciences; Populations; Spores; Canker pathogen; Local adaptation; Pathogen-induced selection for resistance; Proteaceae; Population dynamics; Morphological, pathogenic and genetic diversity; Isozymes; Resistance mechanisms
• ISSN: 0815-3191; 1448-6032
• DOI: 10.1007/s13313-015-0346-7

Diversity within and between Cryptodiaporthe melanocraspeda populations on Banksia spp. and variation in susceptibility within B. coccinea that resulted from pathogen-induced selection, was investigated. Genetic distances between C. melanocraspeda isolate populations were much less than those between Cryptodiaporthe spp. Spore size and rates of lesion extension of isolate populations of C. melanocraspeda formed continua that reflected intraspecific variation within a species. There were two isozyme groups amongst the populations of C. melanocraspeda from different Banksia hosts. Populations of C. melanocraspeda from the five geographic clusters could be divided into three geographic isozyme groups. Pycnidiospore size of populations of C. melanocraspeda isolates from different Banksia hosts formed a continuum from relatively short-thin spores for isolates from B. sessilis and relatively long-wide spores for isolates from B. baxteri . The rate of lesion extension formed a continuum, with ranking of isolates from slowest to fastest rates differing on the four hosts inoculated. Isolate populations varied in their pattern of adaptation to local Banksia host populations. Although intraspecific variation in the response of B. coccinea to C. melanocraspeda was mainly skewed to highly susceptible trees, there would be the potential for the conservation of diversity through single-tree selection for resistance and breeding.