Skip to main content

Table 3 Comparison of morphological characters and dimensions, and temperature-growth relations of Phytophthora palmivora, P. frigida, P. alticola (from original description, holotype and paratype material and living isolate CMW 19425 = CMW 34279), P. boodjera, and P. arenaria.

From: Phytophthora boodjera sp. nov., a damping-off pathogen in production nurseries and from urban and natural landscapes, with an update on the status of P. alticola

Species and sources of data P. palmivora (Erwin & Ribero, 1995) P. frigida (Maseko 2007) P. alticola (holotype 1 ) PREM 59215 P. alticola (paratype 2 ) PREM 59217 P. alticola (Maseko 2007) CMW 34279 3 (this study) P. boodjera (this study) P. arenaria (Rea 2011) P. arenaria (this study)
No of isolates   10    10 1 12 10 9
Sporangia (mm)          
LxB mean 45.3 × 29.8 33 × 37 31.1 ± 5.0 × 30.9 ± 4.5   36 × 28 38.9 ± 5.4 × 28.6 ± 4.3 39.2 ± 4.4 × 29.7 ± 3.4 31.8 ± 4.6 × 23.7 ± 3.5 23.9 ± 3.1 × 19.8 ± 3.4
Range 40–60 × 25–35 24–40 × 20–33 27.7–45.7 × 23.0–29.4   30–45 × 20–35 20.4–60.7 × 19.0–38.9 15.2–64.5 × 13.9–42.5 20.2–53.0 × 12.5–35.0 12.7–38.5 × 9.9–30.7
Range of isolates means      na na 32.6–44.6 × 24.7–33.3 28.9–34.8 × 21.4–28.3 19.5–24.9 × 16.0–23.1
L/B ratio 1.2–1.8 1.22 1.21 ± 0.12   1.4 (<1.6) 1.35 ± 0.03 1.27 ± 0.16 1.40 ± 0.17 1.22 ± 0.20
Range of isolates means      na na 1.19–1.35 1.2–1.5 1.08–1.65
Sporangial characteristics Papillate Papillate, rarely bipapillate Papillate   Papillate, rarely bipapillate Papillate, rarely bipapillate or bilobed Papillate, rarely bipapillate or bilobed Papillate, rarely bi/tripapillate or bilobed Papillate, rarely bipapillate or bilobed
Persistence caducous caducous semi-caducous   caducous persistent persistent persistent persistent
Sporangiophores Lax or close sympodia simple Lax or close sympodia   simple or branched sympodia simple or branched sympodia often with bulbous base, very often laterally attached simple or branched sympodia often with bulbous base, very often laterally attached simple or branched sympodia often with bulbous base simple or branched sympodia often with bulbous base, very often laterally attached
Sporangia shape ellipsoid, ovoid spherical ovoid, sometimes obpyriform Usually ovoid to broad ovoid   usually ovoid or ellipsoid, sometimes obpyriform or peanut-shaped ovoid 66%, limoniform 14%, peanut-shaped 8%, obpyriform 6%, distorted 6% ovoid 64%, limoniform 20%, peanut-shaped 10%, distorted 6% usually ovoid, also obpyriform or distorted ovoid 40%, subglobose 20%, globose 14%, obpyriform 12%, distorted 4%
Proliferation absent absent absent   absent absent absent absent absent
Exit pores (mm)          
Width   5–6    6 6.21 ± 0.53 6.09 ± 1.02 6.00 ± 1.00 5.50 ± 0.95
Width range   5–10    4–8 5.00–7.10 4.85–8.89 3.40–8.90 3.88–7.10
Chlamydospores (mm) 32–42 24–26 42.6 ± 5.8   Some isolates 28 (20–35) absent absent absent absent
Hyphal swellings   Spherical    Irregular Catenulate, some with radiating hyphae Catenulate, some with radiating hyphae Catenulate, globose to sub-globose, some with radiating hyphae Catenulate, globose to sub-globose, some with radiating hyphae
Mean diameter (mm)      na 14.7 15.2 na 12.8
Breeding system Heterothallic Heterothallic   Homothallic Homothallic Homothallic Homothallic Homothallic Homothallic
Oogonia (mm)          
Mean diameter   38   26.2 ± 2.3 284 27.3 ± 1.9 29.4 ± 2.3 25.3 ± 2.2 26.6 ± 1.6
Diameter range 22–34.8 24–48   24–37 20–35 22.03–31.07 24.3–33.9 19.6–34.3 20.5–29.6
Range of isolates means      na na 24.6–33.4 24.3–28.1 23.6–28.8
Oospores (mm)          
Mean diameter 22.8 ± 0.1 33   26.2 ± 2.1 30 (28.3 × 30.5) 24.9 ± 2.1 25.5 ± 1.9 22.3 ± 1.8 23.8 ± 1.6
Diameter range 22.8 25–42   21–31 24–36 20.3–29.5 20.92–29.3 16.0–28.3 17.8–28.6
Range of isolates means      na na 21.3–29.5 21.4–23.9 21.5–25.9
Wall thickness      na 2.51 ± 0.4 2.47 ± 0.33 2.30 ± 0.34 2.57 ± 0.22
Oospore wall index   na   0.57 ± 0.01 na 0.54 ± 0.05 0.47 ± 0.05 0.50 ± 0.05 0.53 ± 0.06
Oogonial characteristics Aplerotic Aplerotic   Aplerotic Markedly aplerotic, oospores with thick inner walls Aplerotic oospores Mature oogonia with a slightly wavy surface and golden-brown discoloration often with tapering base Aplerotic oospores Mature oogonia with a slightly wavy surface and golden-brown discoloration Aplerotic oospores Mature oogonia with a slightly wavy surface and golden-brown discoloration Aplerotic oospores Mature oogonia with a slightly wavy surface and golden-brown discoloration
Antheridia Amphigynous Amphigynous   Amphigynous Mainly amphigynous Paragynous, often with finger-like projections Paragynous Paragynous, often with finger like projections Paragynous
LxB mean (mm)      na 10.6 ± 2.3 × 8.3 ± 1.4 10.4 ± 1.9 × 8.3 ± 1.5 11.2 ± 1.7 × 8.4 ± 1.3 10.0 ± 2.1 × 7.5 ± 1.3
LxB range (mm)      na Na 8.2–10.9 × 7.3–10.6 7.9–16.4 × 6.0–10.5 6.4–13.8 × 5.6–12.8
Growth Characteristics          
Max temp (°C) 34 30 to <35    30 to <35 35 35 32.5 35
Opt temp (°C) 27.5–30 25    25 20–25 25–30 30 25
Min temp (°C) 11 >5<10    >10<15 >10<15 >10<15 >10<15 15
Lethal temp (°C)      na >37.5 >37.5 na <37.5
Growth rate at optimum (mm/day)   ca. 7.5 (CA), ca. 8 (V8A)    ca. 4.5 (CA), ca. 7 (V8A) 8.20 (V8A) 9.18 (V8A) 5.9–7.4 (CA) 8.65 (V8A)
Growth rate at 20°C (mm/day)   5 (V8A), 3.0 (CA)    4.5 (V8A), 3.0 (CA) 7.75 (V8A) 6.12 (V8A) 3.8–5.2 (CA) 5.96 (V8A)
Colony morphology On CA, stellate, defined edge, aerial mycelium in centre Stellate-petaloid on V8, CA, PDA and MEA, moderately fluffy    Uniform and fluffy on MEA and V8A, stellate with limited aerial mycelium on CA and PDA Appressed and cottony with no distinctive growth pattern and regular smooth margins on CA, V8A and PDA; sparse, slow growth on MEA Appressed with no distinctive growth pattern and regular smooth margins on CA, V8A, MEA and PDA Radiate to faintly radiate with very limited aerial mycelium and regular smooth margins on CA, V8A, MEA and PDA Appressed with no distinctive growth pattern and regular smooth margins on CA, V8A and PDA, sometimes slightly petaloid on V8A; sparse on MEA
  1. 1Morphological features of paratype PREM 59214 = CMW 19416 same as holotype PREM 59215 = CMW 19417, caducous, papillate sporangia in close sympodia and chlamydospores present. No oospores observed.
  2. 2Morphological features of paratype PREM 59216 = CMW 19424 same as paratype PREM 59217 = CMW 19425 = CMW 35479; amphigynous, aplerotic oospores turning brown on maturity. No sporangia or chlamydospores observed.
  3. 3Isolate CMW 19425 = CMW 35429 = CBS 121939 = WPC 16948 is the only isolate still surviving from the original description of P. alticola (Maseko et al. 2007) and it is linked to PREM 59217. Note: when all isolates were lost in the CMW collection, the remaining isolate CMW 19425 was renamed CMW 35429 and it is this isolate that was sent to the World Phytophthora Collection and given the code P 16948.
  4. 4Measurements from Maseko et al. (2007) where oospores were misrepresented to be larger than oogonia.