Table 1.
Nematode samples used in this study.
| Population code | Collection date | Host plant | Coordinates |
|---|---|---|---|
| SG936 | July 27, 2016 | Rice | 36.902188, 126.661624 |
| SG153 | August 16, 2017 | Rice | 36.901005, 126.671008 |
Table 2.
Morphometrics of second-stage juveniles and cysts for the Heterodera sp. of two populations SG153 and SG 936 as compared to H. oryzae and H. elachista in previous studies.
| Population | SG936, South Korea, This study | SG153, South Korea, This study | H. oryzae, Côte d’Ivoire, Nobbs et al. (1992) | H. elachista, Japan, Nobbs et al. (1992) | H. elachista, Iran, Tanha Maafi et al. (2004) |
|---|---|---|---|---|---|
| Cysts (n) | 13 | 25 | 50 | 50 | 39 |
| Length (excl. neck) | 498.9 ± 96.4 (307.0-617.2) | 523.3 ± 54.5 (438.9-643.3) | 714.8 ± 71.5 (442-999) | 446 ± 30.3 (328-557) | 431 ± 48 (340-586) |
| Width | 429.3 ± 97.3 (251.2-550.1) | 360.2 ± 47.2 (288.3-447.8) | 426.6 ± 53.8 (229-655) | 322.6 ± 26.0 (229-449) | 311 ± 48 (225-540) |
| Length/width | 1.2 ± 0.1 (1.0-1.4) | 1.5 ± 0.2 (1.3-1.8) | 1.71 ± 0.12 (1.1-2.3) | 1.4 ± 0.1 (1.1-1.9) | 1.4 ± 0.2 (1.1-1.9) |
| Vulval areas (n) | 11 | 16 | 10 | 10 | 10 |
| Fenestral length | 36.5 ± 4.7 (28.2-40.9) | 34.2 ± 4.9 (24.8-43.6) | 38.8 ± 1.85 (32-46) | 29.3 ± 2.0 (23.36) | 40 ± 6.5 (30-50) |
| Semifenestral width | 34.8 ± 4.4 (29.3-44.2) | 35.7 ± 4.4 (25.9-41.0) | 51.6 ± 5.20 (36-69) | 32.0 ± 2.5 (26-39) | 31.2 ± 4.7 (26-42) |
| Vulval slit length | 33.1 ± 5.0 (27.6-45.6) | 34.3 ± 3.8 (27.8-41.3) | 50.7 ± 4.0 (41-65) | 37.5 ± 2.8 (26-46) | 40 ± 3.8 (32-45) |
| Vulval bridge width | 9.0 ± 4.5 (4.4-17.9) | 7.2 ± 3.3 (4.0-15.0) | 12.14 ± 1.9 (6-16) | 5.8 ± 2.0 (2-16) | – |
| Underbridge length | 80.1 ± 7.2 (70.8-96.4) | 83.0 ± 7.9 (63.4-95.3) | 112.5 ± 9.0 (87-153) | 72.0 ± 2.9 (65-78) | 85 |
| Vulva to anus distance | 34.9 ± 3.0 (30.5-41.6) | 36.6 ± 5.9 (30.1-50.3) | – | – | – |
| J2 (n) | 11 | 11 | 20 | 20 | 10 |
| L | 450.6 ± 16.6 (414.7-478.6) | 472.4 ± 19.3 (433.1-495.1) | 554 ± 9.4 (523-589) | 402 ± 10.0 (377-450) | 391 ± 11 (372-410) |
| a | 23.4 ± 0.7 (22.4-24.6) | 23.3 ± 1.6 (20.1-25.9) | 34.0 ± 1.03 (30.1-39.3) | 24.6 ± 0.9 (21.3-28.1) | 22.5 ± 1.0 (20.8-24) |
| b | – | – | |||
| c | 6.8 ± 0.3 (6.3-7.4) | 6.8 ± 0.3 (6.3-7.2) | 9.4 ± 0.3 (8.6-10.7) | 7.0 ± 0.4 (5.4-8.4) | 6.7 ± 0.3 (5.9-7.2) |
| Stylet (S) | 21.1 ± 0.5 (20.4-22.4) | 21.1 ± 0.8 (19.5-22.6) | 20.5 ± 1.15 (16-25) | 19.2 ± 0.8 (16-21) | 20 ± 0.7 (18-21) |
| Labial region height | 4.7 ± 0.5 (3.8-5.4) | 4.7 ± 0.3 (4.3-5.3) | – | – | 3 |
| Labial region diam. | 9.0 ± 0.7 (7.8-10.1) | 9.1 ± 0.3 (8.7-9.6) | – | – | 7.8 ± 0.4 (7-8) |
| DGO | 7.3 ± 0.7 (6.5-8.4) | 6.0 ± 0.8 (4.9-7.7) | – | – | 5.2 ± 0.8 (4-7) |
| Anterior end to | |||||
| Excretory pore | 97.5 ± 4.8 (87.5-103.0) | 99.3 ± 6.6 (84.8-110.8) | – | – | 84 ± 2.8 (79-88) |
| Median bulb valve (MB) | 65.4 ± 2.7 (62.1-72.6) | 64.4 ± 2.2 (60.6-68.0) | – | – | 59 ± 3.6 (52-67) |
| Body diam. at | |||||
| Mid-body | 19.2 ± 0.8 (18.1-20.7) | 20.4 ± 1.9 (18.2-24.3) | 16.3 ± 0.43 (15-18) | – | 17.4 ± 0.8 (16-19) |
| Anus (BDA) | 12.6 ± 0.9 (11.7-14.5) | 13.3 ± 0.8 (12.0-14.6) | 12.3 ± 0.72 (10-15) | 11.4 ± 0.8 (10-13) | 10.2 ± 0.6 (9-11) |
| Hyaline region (H) | 36.9 ± 3.2 (29.3-41.0) | 35.8 ± 3.4 (31.6-42.4) | 32.8 ± 1.3 (26-44) | – | 32 ± 3.0 (25-39) |
| Tail length (Tl) | 66.9 ± 3.8 (60.5-73.4) | 69.6 ± 4.7 (60.6-78.9) | 58.8 ± 2.25 (49-66) | 57.8 ± 2.9 (47-70) | – |
| H/S | 1.7 ± 0.1 (1.4-1.9) | 1.7 ± 0.2 (1.4-2.0) | 1.6 ± 0.11 (1.4-2.2) | – | 1.6 ± 0.1 (1.3-1.9) |
| L/MB | 6.9 ± 0.2 (6.6-7.2) | 7.3 ± 0.3 (6.9-8.1) | – | – | 6.7 ± 0.4 (5.6-7.4) |
| Tl/H | 1.8 ± 0.2 (1.6-2.5) | 2.0 ± 0.1 (1.7-2.2) | – | – | – |
Figure 1:
Morphological characteristics of cyst, vulval cone, and second-stage juvenile of Heterodera sp. (SG936). A-C: Cysts, (A) Lemon-shaped cyst (B) Anterior view (C) Underbridge level view, D-H: Second-stage juveniles (J2), (D) Entire J2 body (E) Stylet (F) Lateral field (G) Pharyngeal region (H) Tail region (black arrow: anus). *Scale bars: A = 100 μm, B = 50 μm, C = 50 μm, D = 100 μm, E = 20 μm, F = 10 μm, G = 50 μm, and H = 50 μm.
Figure 2:
Morphological characteristics of cyst, vulval cone, and second-stage juvenile of Heterodera sp. (SG153). A-C: Cysts, (A) Lemon-shaped cyst (B) Anterior view (C) Underbridge level view, D-H: Second-stage juveniles (J2), (D) Entire J2 body (E) Stylet (F) Lateral field (G) Pharyngeal region (H) Tail region (black arrow: anus). *Scale bars: A = 100 μm, B = 50 μm, C = 50 μm, D = 100 μm, E = 20 μm, F = 10 μm, G = 50 μm, and H = 50 μm.
Figure 3:
PCR results for ITS region, 28S D2-D3, and COI gene of SG153 and SG936 nematode populations with their respective universal primers using 100 bp DNA ladder.
Figure 4:
Phylogenetic relationship between two Heterodera populations (SG936, SG153) with selected representative sequences from many of the world known Heterodera species as inferred from Bayesian analysis of the internal transcribed spacer (ITS) sequence dataset. The newly obtained sequences were in bold. Posterior probability values more than 50% are given for appropriate clade.
Figure 5:
Phylogenetic relationship between two Heterodera populations (SG936, SG153) with selected representative sequences from many of the world known Heterodera species as inferred from Bayesian analysis of the cytochrome c oxidase subunit I of mitochondrial DNA sequence dataset. The newly obtained sequences were in bold. Posterior probability values more than 50% are given for appropriate clade.