JASPER, DAVID, JENNIFER BELL, SIMONE MERCER & LYN ABBOTT.
Centre for Land Rehabilitation, The University of Western Australia, Nedlands, WA, 6907, AUSTRALIA.
Inoculum of AM fungi usually consists of spores and/or roots
and hyphae, in a mix with soil or an inert medium. Such inocula can be bulky
and heavy, restricting their applicability for large areas. A more-concentrated,
robust inoculum of locally-adapted fungi, may enhance the potential to inoculate
areas such as mine sites where many hectares may need to be revegetated.
Our research has focused on developing protocols for production and use of dry
root fragments as an inoculum of AM fungi. Many Glomus spp. have the
capacity to regrow from dry roots. However, the conditions of drying and cutting
are important to subsequent infectivity of the mycorrhizal roots. We have defined
a protocol in which a Sorghum x Sudangrass hybrid is grown in inoculated soil
and the roots harvested and processed to give a highly-infective inoculum. The
inoculum can be used successfully at rates as low as 40 mg / kg soil for some
species. In the field, the inoculum has been used to establish mycorrhizal associations
on native species at a rate of 2 g / m of inoculated row.
The key elements of the production process, and details of glasshouse and field
testing will be described.