Effects of inoculating Lachnum and Cadophora isolates on the growth of Vaccinium corymbosum.

The roots of ericaceous plants harbour a diversity of fungal taxa, which confer eco-physiological benefits to the host. Some of the fungi have been established to form ericoid mycorrhizal (ERM) associations and enhance plant growth in certain ericaceous genera. Although, Lachnum and Cadophora isolates have frequently been identified from the roots of this family, the status of their association and functional roles is still vague. The aims of this study were to identify Lachnum and Cadophora isolates; determine the root-fungal interactive structures formed in associations with Vaccinium corymbosum L. (blueberry) hosts and to examine inoculation effects of the fungal associates using several varieties of the blueberry. Lachnum and Cadophora were isolated and identified from Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth using morphological and molecular techniques. Micropropagated blueberry varieties (Bluecrop, Elliott, Spartan, Chandler and Brightwell) were inoculated with respective fungi and plant growth evaluated. Both fungi colonised the roots and did not have any pathogenic effect. Lachnum isolate did not form any particular mycorrhizal structures whereas; Cadophora inoculated plants showed typical ericoid mycorrhizal coils. Inoculation with both fungi enhanced the shoot growth of Brightwell and Elliott varieties. However neutral effects were observed in the remaining varieties. In conclusion, Cadophora and Lachnum isolates have potential to promote growth of selected blueberry varieties.