Effect of Eliminating dsRNA in HypovirulentEndothia parasitica

Comparison of procedures to evaluate the pathogenicity of Ceratocystisfimbriata sensu lato isolates from Eucalyptus in South Africa

“…A number of studies have evaluated the pathogenicity of fungi using the fastest-growing isolates in culture (Fulbright 1984, Brasier and Webber 1987, Enebak et al 1994. For example, Brasier and Webber (1987) reported a positive correlation between in vitro growth rate and pathogenicity of Ophiostoma ulmi, although this correlation was not consistent in all their experiments.…”

“…Inoculations on apples have been applied to reflect the relative pathogenicity of isolates of fungal pathogens (Fulbright 1984, Enebak et al 1994, de Lange et al 1998. Results obtained from the apple inoculation study showed a moderate to weak correlation with the pathogenicity results emerging from field inoculations.…”

“…Pathogenicity tests provide an important step in the process of determining whether fungi, including Ceratocystis spp., have the capacity to cause disease on trees from which they have been isolated (Fulbright 1984, Agrios 1994, Heath et al 2009). Ideally, inoculations are made on healthy trees of the same species as those from which the pathogen was originally isolated, but this is a destructive process that is typically costly and time consuming because trees often need to be reared from seed or cuttings and they are relatively slow growing.…”

“…Ideally, inoculations are made on healthy trees of the same species as those from which the pathogen was originally isolated, but this is a destructive process that is typically costly and time consuming because trees often need to be reared from seed or cuttings and they are relatively slow growing. Examples of techniques used for pathogenicity tests with tree pathogens include inoculation of branches or stems with agar plugs (Fulbright 1984, Enebak et al 1994 or gauze (Conradie et al 1992) on which the fungus has been cultured, or by injecting spore suspensions into artificially made wounds (Brasier andWebber 1987, Chongo andGossen 2001). Tests are either conducted under controlled conditions in a greenhouse, or under field conditions, depending on the availability of trees and the origin of the fungus to be tested.…”

“…Model systems for pathogenicity tests frequently use seedlings in greenhouses but these can result in low levels of correlation between field results and greenhouse experiments (Conradie et al 1992, van der Westhuizen et al 1992, Hong and Hwang 1998. Other characteristics, for example considering rate of growth in culture or inoculations on fruit such as apples (Fulbright 1984, Enebak et al 1994, de Lange et al 1998 have also been used to reflect pathogenicity of fungi, but these are valuable only if they are known to correlate with results from field tests.…”