Genotype-dependence in the interaction betweenGlomus fistulosum, Phytophthora fragariae and the wild strawberry (Fragaria vesca)

Abstract

Root colonisation by Glomus fistuIosum BEG 31 of a plant population from the outbreeding wild strawberry (Fragaria vesca) ranged from 42 to 80%; this was correlated with a significant increase in fruit trusses, berries and leaves. The mycorrhizal plants produced significantly more primary and secondary runners but less lateral runners. One hundred randomly selected seeds were multiplied in vitro and 4 clonal populations were selected. Root colonisation in the clones varied from 16 to 75%, with significant difference in the % colonisation between some of the clones. Percentage mycorrhizal colonisation was positively correlated with effects on host growth.The positive correlation between mycorrhizal root colonisation and growth effects in the clones was not reflected in their respective susceptibility, in the non-mycorrhizal state, to Phytophthorafragariae infection. Clones showing the highest and lowest mycorrhizal root colonisation showed high disease susceptibility whereas a clone with intermediate cotonisation was resistant. When the clones were colonised with mycorrhizal fungi, the two susceptible clones became resistant to P. fragariae whereas the resistant and partially-resistant clones were less affected. Only one clone showed variation in vesicle formation when challenged with P. fragariae.Abbreviations: AMF -arbuscular mycorrhizal fungi, DSI -Disease severity index.

Effects of arbuscular mycorrhizas on reproductive traits in sexually dimorphic plants: a review

“…For example, inoculation with Glomus intraradices increased runner production in Fragaria × ananassa (Varma and Schuepp, 1994) and Glomus fistulosum increased the runner number in Fragaria vesca (Mark and Cassells, 1996). Botham et al (2009) also reported an increase in the number of plantlets produced by Fragaria virginiana in association with a commercial mixed inoculum containing Entrophospora columbiana and Glomus intraradices.…”

Establishment of arbuscular mycorrhizal fungi in autotrophic strawberry cultures in vitro. Comparison with inoculation of microplants in vivo

“…Microplants of Fragaria vesca L were established via aseptic seed germination as described previously (Mark and Cassells, 1996) …”

“…Elsewhere, it has been shown that these benefits extend to field performance (Mark and Cassells, 1996).…”

Increased Tolerance to Fusarium Wilt in Mycorrhizal Strawberry Plants Raised by Capillary Watering Methods

“…Our data supports their finding, but we could not clarify the difference in the tolerance to fusarium wilt among AM fungal species. Mark and Cassells (1996) mentioned that no relationship between AM fungal infection level in roots and the tolerance to Phytophthora fragariae occurred in strawberry plants. In our study, no characteristic relationship between AM fungal infection level and the tolerance to fusarium wilt was observed, so that AM fungal infection level might have no major association with the disease tolerance.…”

“…As for strawberry plants, growth enhancement through AM fungus inocula-tion was reported in several combinations of AM fungal species and strawberry cultivars (Robertson et al, 1988;Chavez and Ferrera, 1990;Niemi and Vestberg,1992 ;Williams et al, 1992;Varma and Schuepp, 1994). In addition, trials to inoculate Phytophthora fragariae to strawberry plants infected with AM fungus were reported and the effect of disease reduction differed with host cultivar and AM fungal species (Baath and Hayman, 1984;Mark and Cassells, 1996;Norman et al, 1996). On the other hand, Kobayashi (1988) and Singh et al (2000) mentioned that AM fungus-infected plants showed tolerance to fusarium diseases in several crop plants except strawberry.…”