Identification of fungal mycorrhizal species associated with increased plant growth of the rare Fabaceae species Gastrolobium vestitum

Summary of final report on the Australian Flora Foundation funded project:

Dr Celeste Linde

Research School of Biology, The Australian National University, Canberra ACT 0200

Grant Details    Final Report

Ectomycorrhizal (EM) associations were studied for two species of Gastrolobium from the Stirling Ranges, Western Australia, from two locations; Mt Toolbrunnup and Mt Hassell. One of the species, G. vestitum occurs at low frequencies while the other, G. rubrum, occurs abundantly. This study was aimed at identifying the EM associations of the two Gastrolobium species, whether EM associations could explain the differences in plant success, as well as identifying which EM associations promote plant performance most. The most successful EM associations were then planned to be cultivated in vitro to assist cultivation of G. vestitum, an aesthetically attractive candidate for the garden industry. Sequence analyses of the ITS region of EM colonized root tips revealed at least 11 different EM associations are associated with G. vestitum in the 20 plants studied. Similarly, G. rubrum is associated with a large number of EM fungi, some of which could not be identified with the PCR primers used in this study. None of the EM associations identified with ITS sequencing was shared between the two Gastrolobium species, indicating host specificity. However, EM types were also not shared between the two locations studied (Mt Hassell and Mt Toolbrunnup), indicating the ability to associate with a diverse range of EM fungi which is good for plant diversity and performance. Unfortunately a hailstorm prematurely terminated the growth trials to assess which EM fungi are most successful in promoting plant performance.