Effects of different rates of Gaeumannomyces graminis var. tritici inoculum for detecting take-all suppression in soils

• Published in: Australasian plant pathology 2013, Vol.42 (1), p.103-109
• Main Authors: Chng, S. F., Stewart, A., Cromey, M. G., Dodd, S. L., Butler, R. C., Jaspers, M. V.
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Ecology; Entomology; Life Sciences; Plant Pathology; Plant Sciences
• ISSN: 0815-3191; 1448-6032
• DOI: 10.1007/s13313-012-0166-y

The introduction of Gaeumannomyces graminis var. tritici ( Ggt ) inoculum into soils to screen for take-all suppression has been widely used in field and laboratory studies. However, the amounts of Ggt inoculum reported have varied greatly. The effects of adding Ggt in sand/maizemeal to three soils of different cropping history at the rates of 0, 0.2, 0.5, 1 and 4 % (w/w) were investigated in a pot assay using wheat plants. The three soils had previously been cropped with ryegrass for 5 years, wheat for 8 years, and wheat for 2 years. The soils represented a putative non-suppressive, non-wheat soil; a suppressive wheat soil; and a non-suppressive wheat soil, each containing natural background concentrations of Ggt DNA of 0, 200 and 1126 pg g −1 soil, respectively. Root assessments of wheat plants after 4 weeks growth showed that 4 % of Ggt reduced root growth slightly, decreased water uptake of the wheat plants and effectively differentiated the suppressive activity of the soils ( P