Figure 1.
The plants on the right illustrate suppression of clubroot on canola by a granular formulation of Heteroconium chaetospira BC2HB1 incorporated into the planting mix at 2.5% (w/v).
Plants on the left are from an untreated control. Each plant was inoculated with a suspension of Plasmodiophora brassicae resting spores at 2×105 spores pot−1 immediately after seeding.
Table 1.
Clubroot severity (disease severity index - DSI) on canola plants treated with a granular formulation of Heteroconium chaetospira strain B2HB1 (Hc) under high and low inoculum pressure of Plasmodiophora brassicae (Pb) added to the growth medium at seeding (0 DAS) or 7 days after seeding (7 DAS) (n = 3)x
Table 2.
Colonization of canola roots by Heteroconium chaetospira strain BC2HB1 (Hc) based on qPCR, with or without inoculation with Plasmodiophora brassicae (n = 9).
Figure 2.
The effect of BC2HB1 treatments on the amount of Plasmodiophora brassicae in canola roots (ng DNA/g fresh root, qPCR) at 14 days after seeding.
The BC2HB1 formulation was incorporated at 1.25% or 2.5% (w/v) into the planting mix prior to seeding and resting spores of P. brassicae were applied at 2×105 spores pot−1 after seeding (n = 9).
Figure 3.
The relationship between colonization of canola roots by BC2HB1 (ng DNA/g of fresh root) at 14 days after seeding and clubroot severity (DSI) at 5 weeks after seeding.
The plants were inoculated with Plasmodiophora brassicae at 2×105 spores pot−1 (low inoculum dose).
Figure 4.
Colonization of canola roots by Heteroconium chaetospira BC2HB1 at 14 days after seeding, observed using confocal microscopy.
A: fungal hyphae (arrows) in the cortical tissue of a canola root; B: An animation of a profile view of root colonization by fungal hyphae (red, arrow pointed), constructed from 60 confocal microscopic images taken every 1.5 μm from top to bottom of the root sample (in green color).
Table 3.
Mean phenylalanine ammonia lyase (PAL) activity in fresh leaves, stems and roots of canola plants treated with Heteroconium chaetospira strain BC2HB1 at 1.25 or 2.5% (w/v) with or without inoculation with Plasmodiophora brassicae (Pb) (n = 6)x
Table 4.
The expression (transcript levels) of nine genes potentially related to defence responses in canola at 14 days after a treatment with Heteroconium chaetospira BC2HB1 plus Plasmodiophora brassica (Pb) or Pb alone, relative to the control (n = 8).