Development of commercial molecular biological assays for improved sugarcane soil health and productivity : final report 2018/009

Abstract

Project research has shown that the DNA-based molecular assays for Pachymetra chaunorhiza, Pratylenchus zeae and Meloidogyne species quantify soil populations in field samples, confirming research undertaken in project 2016047, and has also confirmed the importance of sampling strategy and storage for obtaining representative data. Some further research is needed with P. chaunorhiza to ensure the accuracy of the molecular assay; the focus should be on sample storage conditions, amongst other things. Soil samples were processed from soil health projects, plant breeding selection trials and industry samples sent to the Tully soil assay laboratory.

The effects of storage temperature and time on results obtained from manual and molecular assays for P. chaunorhiza, P. zeae and Meloidogyne species were examined. Storage at 400C for even a short period led to failure of molecular assays to detect the parasitic nematode species. P. chaunorhiza manual counts were also affected, but only after 14 days.

For molecular assay of nematode samples, storing soils at 40C or 250C was the most effective way to ensure accurate results, but this was not so for the manual assay. Molecular assays for mycorrhizae and free-living nematodes (used to assess soil biological health) developed for other industries were found to be potentially useful for the sugarcane industry.