Table 8.
Morphological characters and dimensions (mean ± SD; μm), cardinal temperatures (°C) and temperature-growth relations (mm/d) on V8-juice agar of Phytophthora species from Subclade 10c. Most discriminating characters are highlighted in bold. Percentages in brackets are ranges of isolate means. – indicates character not observed.
| Subclade 10c | ||||||||
|---|---|---|---|---|---|---|---|---|
| P. kernoviae (Chile) | P. kernoviae (Ireland) | P. chilensis | P. pseudochilensis | P. pseudokernoviae | P. celebensis | P. javanensis | P. multiglobulosa | |
| No. of isolates/source | 5a | 3a | 6a | 6a | 4a | 5a | 10a | 3a |
| Sporangia | 91.2 % broad-ovoid to elongated-ovoid, 5.2 % limoniform (subglobose, ellipsoid, mouse-shaped) | 82.7% broad-ovoid to elongated-ovoid, 13.3% limoniform (subglobose, mouse-shaped) | 91.6% broad-ovoid to elongated-ovoid, 3.3% limoniform (obovoid, obpyriform, ellipsoid) | 74% ovoid to elongated ovoid, 9.5% obpyriform, 8% limoniform-elongated limoniform (ellipsoid, obovoid) | 88% ovoid, 12% limoniform | 52.8% ovoid to broadovoid, 41.6 limoniform, (ellipsoid, subglobose, pyriform) | 53.6% ovoid, 43% limoniform (obovoid, subglobose, ellipsoid) | 57.3% ovoid, 42% limoniform (obpyriform) |
| apex | papillate | papillate, semipapillate | papillate | papillate | papillate | papillate | papillate, few bi papillate | papillate |
| Ixb mean | 44.0 ± 6.1 x 30.8 ± 3.9 | 38.5±4.5 x 25.8±2.7 | 43.3±6.1 x 29.5±3.5 | 48.8±8.2 x 2 7.0 ± 3.1 | 42.7±4.0x29.7±2.8 | 38.7 ± 5.0x26.2 ± 3.3 | 38.3 ± 4.5x23.2 ± 2.9 | 43.1 ±6.2 x 27.1 ± 3.0 |
| range of isolate means | 39.2–49.6 x 27.3–33.7 | 37.1-39.3 x 24.4-26.6 | 41.3-45.5 x 27.3-31.8 | 43.3-54.9 x 25.7-29.3 | 41.9-43.4 x 28.6-31.5 | 37.3–40.7 x 25.0–27.9 | 33.6-41.3 x 20.5-25.6 | 41.1-46.5 x 26.1-28.2 |
| total range | 27.4-59.4 x 19.0-40.0 | 26.7-52.1 x 17.4-32.1 | 20.7-60.3 x 13.4-42.1 | 25.6-69.1 x 17.4-39.4 | 30.5-55.0 x 21.3-35.7 | 26.3–64.3 x 17.6–40.7 | 19.3-62.6 x 9.2-36.7 | 28.3-64.9 x 21.1-36.5 |
| l/b ratio | 1.43 ± 0.13 | 1.50 ± 0.12 | 1.47 ± 0.15 | 1.81 ± 0.24 | 1.44 ± 0.14 | 1.48 ± 0.12 | 1.66 ± 0.19 | 1.60 ± 0.18 |
| caducity | + | + | + | + | + | + | + | + |
| pedicels | 7.8 ± 4.1 | 6.9 ± 3.8 | 4.0 ± 1.4 | 4.9 ± 1.6 | 3.6 ± 1.0 | 9.9 ± 2.7 | 7.4 ± 2.1 | 7.7 ± 3.3 |
| internal proliferation | – | – | – | – | – | – | – | – |
| exitpores | 4.7 ± 0.9 | 3.7 ± 0.5 | 5.3 ± 0.6 | 4.4 ± 0.9 | 5.6 ± 0.7 | 3.7 ± 0.7 | 3.3 ± 0.6 | 3.6 ± 0.5 |
| sympodia | dense, 2-4 (5) sporangia | dense, 2-4 (5) sporangia | dense, 2-4 (5) sporangia | dense, 2-10 sporangia | dense, 2-4 (5) sporangia | dense, 2-5 sporangia | dense, 2-6 sporangia | dense, 2-5 sporangia |
| zoospore cysts | 9.4 ± 0.9; diplanetism | 9.6 ± 1.4; diplanetism | 9.6 ± 1.4 | 9.9 ± 1.2; diplanetism | 9.9 ± 1.6; diplanetism | 8.0 ± 0.8; diplanetism | 8.4 ± 0.7; diplanetism | 9.2 ± 0.8; diplanetism |
| Breeding system Oogonia | homothallic | homothallic | homothallic | homothallic | homothallic golden-brown with age | homothallic | homothallic | homothallic |
| mean diam | 26.0 ± 2.6 | 23.6 ± 2.5 | 24.9 ± 2.6 | 27.3 ± 3.4 | 30.1 ± 4.3 | 24.9 ± 3.1 | 28.1 ± 4.0 | 25.4 ± 3.5 |
| range of isolate means | 25.4-26.9 | 23.0-24.3 | 24.1-25.5 | 25.9-28.5 | 28.1-34.2 | 23.6-25.8 | 27.1-29.2 | 23.2-25.5 |
| total range | 18.2-34.7 | 16.1-31.1 | 14.6-35.4 | 16.3-35.3 | 18.6-39.3 | 13.1-36.1 | 15.6-42.7 | 17.0-38.4 |
| tapering base | 12.8% (0-28%) | 9.3% (6-14%) | 47.7% (22-76%) | 87.5% (72-96%) | 86% (81-88%) | 8.4% (4-14%) | 12.4% (4-22%) | - |
| comma-shaped | 39.6% (20-56%) | 30.0% (24-38%) | 26.7% (12-48%) | 20.5% (14-28%) | 35.3% (24-42%) | 22.4% (16-32%) | 25.7% (10-40%) | 18.7% (12-26%) |
| elongated/excentric | 17.6% (10-30%) | 15.3% (12-22%) | 2.3% (0-4%) | 11.5% (4-18%) | 16.0% (6-28%) | 7.6% (4-14%) | 16.4% (10-24%) | 6.0% (4-10%) |
| Oospores | ||||||||
| plerotic oospores | 99.6% (98-100%) | 99.7% (99-100%) | 88.0% (80-92%) | 91% (86-96%) | 99.6% (98-100%) | 100% | 80.3% (58-92%) | 100% |
| mean diam | 22.7 ± 2.1 | 20.7 ± 2.3 | 22.8 ± 2.4 | 24.4 ± 3.0 | 27.0 ± 3.7 | 21.9 ± 2.9 | 25.0 ± 3.6 | 22.5 ± 3.2 |
| Total range | 18.1-27.2 | 14.2-26.5 | 13.6-32.6 | 15.4-32.1 | 16.3-35.8 | 12.3-31.5 | 13.5-39.4 | 15.0-35.2 |
| wall diam | 1.96 ± 0.34 | 1.92 ±0.45 | 1.8 ± 0.26 | 1.61 ± 0.33 | 2.07 ± 0.33 | 1.6 ± 0.27 | 1.75 ± 0.34 | 1.5 ± 0.23 |
| oospore wall index | 0.43 ± 0.05 | 0.45 ± 0.06 | 0.40 ± 0.04 | 0.34 ± 0.07 | 0.40 ± 0.06 | 0.38 ± 0.04 | 0.36 ±0.04 | 0.35 ± 0.04 |
| Abortion rate | 20.6% (4-46%) | 40.0% (19-82%) | 8.0% (6-10%) | 65.5% (56-80%) | 7.7% (6-10%) | 24.4% (6-48%) | 16.8% (8-32%) | 7.3% (2-12%) |
| Antheridia | 99.6% amphigynous | 93.3% amphigynous | 100% amphigynous | 100% amphigynous | 95.3% amphigynous | 100% amphigynous | 100% amphigynous | 100% amphigynous |
| size | 11.6±2.0 x 9.4±1.3 | 10.9±2.0 x 8.5±1.2 | 12.7±2.2x9.5±1.1 | 13.7±3.6x9.8±1.7 | 14.6±2.9 x 9.6±1.3 | 11.4±2.1 x 9.8±1.3 | 12.2±2.2 x 10.1 ±1.6 | 11.4 ± 2.1 x 9.9 ± 1.4 |
| Chlamydospores | – | – | – | – | – | – | – | – |
| size | – | – | – | – | – | – | – | – |
| Hyphal swellings | rare; ovoid, subglobose, limoniform; 12.1 ± 0.4 | – | rare; subglob., irregular, limoniform, 10.4 ± 2.4 | rare; subglob., irregular, limoniform, 10.3 ± 2.7 | rare; (sub)globose, limoniform; 9.9 ± 2.1 | – | – | – |
| Hyphal aggregations | + | + | + | + | + | + | + | + |
| Maximum temperature | 20-<25 | 20-<25 | 20-<25 | 20-<25 | 20-<25 | >27.5-<30 | >27.5-<30 | >27.5-<30 |
| Optimum temperature | 20 | 20 | 20 | 15 | 15 | 25 | 20 | 20 |
| Growth rate at 20 °C | 3.08 ± 0.42 | 3.69 ± 0.34 | 2.77 ± 0.07 | 1.57 ± 0.43 | 2.45 ± 0.41 | 2.77 ± 0.19 | 3.36 ± 0.55 | 1.9 ± 0.09 |
| Growth rate at 25 °C | 0 | 0 | 0 | 0 | 0.39 ± 0.13 | 2.87 ± 0.23 | 2.37 ±0.29 | 1.5 ± 0.31 |
aNumbers of isolates included in the growth tests: P. kernoviae (Chile) = 5; P. kernoviae (Ireland) = 3; P. chilensis = 6; P. pseudochilensis = 6; P. pseudokernoviae =3; P. celebensis = 5; P. javanensis = 10; P multiglobulosa = 3.