Pratylenchus subranjani
Mizukubo, Takayuki, Toida, Yukio,
Keereewan, Somkuan, and Yoshida,
Mutsuhiro, 1990

Measurements.  Female:  see Table 1.

Table 1.  Comparison of measurements of Pratylenchus subranjani n. sp. with P. ranjani

                                              P. subranjani n. sp.              Pratylenchus ranjani
Criteria
Mean ± SD (range) Paratypes mean Paratypes (range) Holotype Drw1
L (um)
506 ± 43.8
(386-572)
520
(470-610)
600
620
L’ (um)
473 ± 42.2
(359-537)
4892
-
-
586
A
27.2 ± 1.50
(23.4-31.5)
28.3
(24.5-32.1)
31.5
26.5
B
6.5 ± 0.63
(5.4-8.1)
4.3
(3.5-5.3)
-
8.0
B’
4.1 ± 0.35
(3.3-4.8)
-
-
5.3
5.2
C
15.6 ± 1.14
(13.2-18.3)
16.5
(11.7-21.4)
21.4
18.1
C’
2.9 ± 0.25
(2.5-3.5)
>2
-
-
2.5
V (%)
74.7 ± 0.99
(73.0-77.0)
74.1
(74-80)
75
75.1
V’ (%)
79.8 ± 1.03
(78.0-82.2)
78.72
-
-
79.5
VL (um)
378 ± 33.9
(282-433)
3852
-
-
465
Spear (um)
16.9 ± 0.42
(16.2-18.5)
15
(15-17)
16
15.5
D.g.o.3 (um)
3.3 ± 0.56
(2.6-5.3)
3
-
-
3.7
MB (%)
68.1 ± 4.42
(59.1-76.9)
-
-
-
68.5
Ex. pore4 (um)
79.7 ± 4.91
(70.0-91.7)
-
-
-
87.4
E.P.5 (%)
15.8 ± 0.90
(14.3-18.1)
-
-
-
13.4
V-a6 (um)
95.3 ± 10.0
(77-118)
1042
-
-
116
Tail (um)
32.5 ± 2.7
(27.1-38.3)
31.52
-
-
34
Tail annules
26.6 ± 3.1
(21-33)
-
(25-35)
-
34
Tail/V-a (%)
34 ± 3
(26-43)
30.22
-
-
29.6
P.u.b. (um)7
40.1 ± 5.56
(29.0-53.5)
-
-
-
47
U
2.3 ± 0.30
(1.6-3.0)
2
-
-
2.0
G2 (%)
8.0 ± 1.1
(5.4-10.7)
-
-
-
7.6
Ph.8 (%)
56.0 ± 7.9
(39.6-77.4)
-
-
-
33.8
                                1Calculated from the drawings.
                                2Calculated from the means of other available dimensions.
                                3Dorsal esophageal gland orifice from knobs of spear.
                                4Excretory pore from anterior body end.
                                5Excretory pore from anterior body end as percentage of body length.
                                6Vulva-anus distance.
                                7Postvulval uterine branch.
                                8Phasmids from tail terminus as percentage of tail length.

Holotype (female):  L = 470 um; L’ = 438 um; a = 27; b = 6.5; b’ = 3.8; c = 14.5; c’ = 3.2; V = 74.9%; V’ = 80.5%; spear = 16.5 um; MB = 73%; G1 = 25%’; G2 = 7.3%; U = 2.2; Tail/V-a = 37.8%; E.P. = 17.0%; Ph. = 66.3%
 Description.  Females (n = 40):  Body curved ventrally when heat-relaxed (Fig. 1, A).  Annules fine, 1.1 um ± 0.14 (0.9-1.4) wide at mid-body.  Lip region medium height, 3.0 um ± (2.3-3.6) high, 8.8 um ± 0.66 (7.6-10.6) wide, rounded and barely flattened anteriorly, mostly continuous to body contour or very slightly off-set.  Labial framework well developed, expanding laterally, highly arched and extending into body at 2 annules.  Lip annules 3 in transmitted light, although it is occasionally difficult to determine whether there are 3 or 4 lip annules due to continuous lip and highly arched labial framework is apparently the 1st body annule.  SEM en face view, though distorted, showed no division between sub-median and lateral segments, classified into “Group 1” of CORBETT and CLARK (1983).  Six inner labial sensilla are observed.  No Cephalids are seen.  Spear moderately long, 1.9 times ± 0.13 (1.6-2.2) the head dia.  Spear knobs massive, 5.0 um ± 0.33 (4.0-5.6) wide, 1.9 um ± 0.23 (1.4-2.3) high: shape varies from flattened anteriorly to acutely indented, calculated 8.5 ± 0.75 (7-10:  n = 40) using knob indices , i.e. mostly in the indented conditions and by no means rounded.  Dorsal esophageal gland orifice at 3.3 um ± 0.56 (2.6-5.3) from spear base.  Metacorpus oval, 12.5 um ± 0.88 (10.6-13.9) long, 8.5 um ± 0.78 (6.9-9.9) across, length 1.5 times ± 0.13 (1.2-1.8) (n = 30) of width, occupying about half of the corresponding body diameter; valve conspicuous, 52.6 um ± 3.56 (38.0-58.1) from anterior body end, or 68.1 % ± 4.42 (59.1-76.9) of esophagus length.  Esophageal gland thin and short, extending 123.1 um ± 10.2 (97.4-155.1) from anterior body end, ventrally overlapping the intestine 45.6 um ± 8.61 (28.4-67.3) or a distance of 2.5 times ± 0.43 (1.6-3.4) the corresponding body diameter; esophageal glands nuclei line up.  Excretory pore 103.2 % ± 7.74 (90.8-119.8) of esophageal length or at the 75th ± 4.35 (65-85) (n = 26) body annules from anterior body end; annules between anterior body end and excretory pore 1.1 um ± 0.11 (0.9-1.3) in average width.  Hemizonid flat, 2.5 to 4 annules long, immediately to 3 annules anterior to excretory pore; hemizonion lenticular, 7.2 ± 2.24 (4-12) annules posterior to excretory pore.
 Gonad outstretched, 126.7 um ± 24.1 (90.4-214.5) (n = 39) long or 25.1 % ± 4.3 (17.4-43.5) (n = 39) of body length; ovary with oocytes in single row; spermatheca empty, rarely observed.  Post-uterine branch long, twice as long as body diameter or longer, in which only the columnar part of the uterus can be recognized.  Vulva plane; vulval lips slightly protruding; vagina tubular, perpendicular to body axis, rarely slightly bent anteriorly, 8.1 um ± 0.80 (6.6-9.9) (n = 38) long or 45.6 % ± 4.44 (36.7-56.6) (n = 29) of vaginal body diameter.  Annules between vulva and anus 81.6 ± 6.0 (67-91) in number, 1.1 um ± 0.11 (0.9-1.3) in average width.
 Tail variable in shape ; sorting 40 individuals according to tail tip shape codes of FREDERICK and TARJAN (1989), their frequencies are:  bluntly pointed (BLP) = 53 %, subhemispherical (SHM) = 30 %, subdigitate (SBD) = 15 % and truncate (TRC) = 3 % respectively.  Presence of tail tip annules is also determined using codes of FREDERICK and TARJAN (1989) with tails in the exact lateral orientation (28 individuals); the frequencies then are:  annulated (ANN) = 71 % (including evidently ANN = 50 % and barely ANN = 21 %), smooth (SHM) = 18 % and cleft (CFT) = 11 % respectively.  Tail terminal cuticle or hyaline part 3.0 um ± 0.6 (1.5-4.3) thick; phasmids pore-like, centered in lateral field, 14.2 um ± 2.64 (7.9-19.1) behind anus or 18.2 um ± 3.34 (12.5-27.7) from tail tip, i.e. 56.0 % ± 7.9 (39.6-77.4) of tail length.
 Lateral fields 5.2 um ± 0.52 (4.0-6.3) wide, i.e. 27.9 % ± 2.54 (23.0-33.3) of widest body diameter.  In transmitted light, this structure appears to have weakly crenate margins and 3 equally spaced plain bands, which gives impression of 4 incisures.  The SEM photograph, however, shows that the outer bands are areolated at intervals of 2, 3 or even more annules in mid-body region and completely in tail region.  The middle band is often sparsely areolated and accompanied by one or 2 accessory incisures.  Lateral fields in transmitted light appear to be closed shortly before the tail tip, but they may extend to tail tip and continue around the tail terminus.
 Males:  Unknown.
 Type host and locality.  Specimens were collected from roots and rhizosphere of maize, Zea mays at Pukae, Phraphutthabat district, Saraburi province, Thailand.
 Type material.  Collected on January 12, 1989 and May 23, 1989 by Y. TOIDA and S. KEEREEWAN.  Holotype (female:  Type no. 28-1) and paratypes (30 females and 10 juveniles) are at the Herbarium and Insect Museum of the National Institute of Agro-Environmental Sciences, Tsukuba City, Ibaraki, Japan.  Paratypes (10 females) are also at the Nematology Section, Department of Agriculture, Bangkok, Thailand.
 Diagnosis and relationshipsPratylenchus subranjani n. sp. shows a close relationship with P. ranjani KHAN and SINGH, 1975 by having rather low V-value (73-77 %), rather low c-value (13.2-18.3), fine annule (0.9-1.3 um), numerous tail annules (21-32), and a long post-uterine branch (29-54 um).  The new species can be distinguished by the presence of 3 lip annules (4 in P. ranjani), position of hemizonid (1-3 annules vs. 5 annules anterior to excretory pore), E.P. value (14.3-18.1 % vs. 13.4 %).
 The other species sharing V-values close to 73-77 % or the lip regions bearing 3 or 4 annules with P. subranjani n. sp. are P. barkati DAS and SULTANA, 1979; P. dasi FORTUNER, 1985; P. delattrei LUC, 1958; P. exilis DAS and SULTANA, 1979; P. goodeyi SHER and ALLEN, 1953; P. morettoi LUC et al., 1986; P. mulchandi NANDAKUMAR and KHERA, 1970; P. nizamabadensis MAHARAJU and DAS, 1981; P. pratensis (DE MAN, 1880); P. pseudopratensis SEINHORST, 1968; P. singhi DAS and SULTANA, 1979; P. thornei SHER and ALLEN, 1953; and P. zeae GRAHAM, 1951.
 On the basis of the ranges in the measurements, the new species cannot be conveniently separated from some of these other species, especially those assigned to the “pratensis group” by FREDERICK and TARJAN (1989).  Differences between P. subranjani n. sp. and these species are indicated in bold letters (Table 2).
 

Table 2.  Characters differentiating P. subranjani n. sp. from relatives
Species V Spear (um) U C Knob idx1 Lip ann. Tail ann. Tail code2 Males code3
Subranjani n. sp. 754 (73-77)5 17 (16-19) 2.3 (1.6-3) 16 (13-18) 8.4 (6-10) 3 (3-4) 27 (21-33) Bip-shm/ann-smo UK
barkati
(74-79)

(18-19)
1 (-)
(17-21)
9 (-) 3 (-) - (18) Shm-sbd/ann UK
dasi
(72-78)

(18-19)

(1-1.5)

(14-21)

(4-5)
3 (-)
(20)
Shm/smo UK
delattrei 75 (73-80)
(16-18)

(1.3)

(18-22)
7 (-) 3 (-)
(<20)
Shm-blp/smo UK
exilis
(73-76)

(17-18)

(0.9-1)

(15-20)

(6-7)
3 (-)
(17-20)
Shm-blp smo K
goodeyi
(73-75)

(16-17)
1 (-)
(16-18)
7 (-) 4 (-) 22 (19-24) Fnp-dlg/smo K
morettoi 76 (73-80) 16 (14-19) 2.7 (2-3.4) 15 (13-19) - (3-4) - (3-4) - (-) Fnp-dlg/- K
mulchandi 77 (75-78)
(16-20)

(1.8)
22 (17-27) 6 (-) 3 (-) - (16-22) Trc-shm blp-smo UK
nizamabadensis
(67-79)

(17-19)

(1.3)

(17-27)
3 (-) 4 (-)
(15-24)
Hem/ann UK
pratensis 75 (74-78) 16 (14-16) - (>1) 19 (14-27) 5 (-) 3 (-) - (20-28) Shm-blp/smo-ann K
pseudopratensis 79 (76-80) 14 (13-15) 1 (-) 22 (19-27) 7 (-) 3 (3-4) 15 (12-19) Hem-shm/smo K
ranjani 75 (73-78) 16 (15-17) 2.0 (-) 17 (12-21) 5-6 (-) 4 (-)
(25-35)
Hem-shm/smo UK
singhi
(75-77)

(17-18)
- (<1)
(18-23)
6 (-) 3 (-) - (-) Shm/smo (UK)
thornei 76 (73-80) 17 (15-18)
(>1.5)
20 (19-25)
(5-7)
3 (-) 23 (19-26) Trc/smo R
zeae 73 (69-75) 16 (15-17) 1 (-) 16 (17-21)
(6-9)
3 (-) 25 (21-26) Blp/smo-ann UK
1Knob indices: refer to Fig 4.
2Tail code: refer to FREDERICK and TARJAN (1989).
3Male code:  K (known); R (rare); UK (unknown); (UK) (males unknown but spermatheca of females filled with spermatozoa).
4Mean.
5Range.