Maqbool, M.A.

Shahina, F.

Horizon / Pleins textes

Heterodera cynodontis n. sp. (Nematoda : Heteroderidae) 
from Cynodon dactylon (L.) in Pakistan 
Fayyaz SHAHINA and Mohammad A. MAQBOOL 
National Nematological Research Centre University of Karachi,  Karachi-32,  Pakistan. 
Heterodera cynodontis n. sp., a member of the “goettingiana group ”, is  described  and  illustrated  from  roots  of  lawn  grass 
(Burmuda  grass), Cynodon dactylon (L.)  in  Karachi. This new  abullate.  species  is  most  closely  related  to H.  graminophila Golden 
& Birchfield,  1972, H. longicolla Golden & Dickerson,  1973, H. elachista Ohshima,  1974 and H. oryzae Luc & Berdon-Brizuela, 
1961  with  a  lemon  shaped  cyst,  no  perianal  pattern,  a  second  stage  juvenile  with  three  lateral  lines,  and  a  mean  of  stylet  length 
less than 22.5  Pm. It differs  from  these  species  by  having  a  shorter  hyaline  tail  terminus in the second  stage-juvenile and  a weak 
and  smaller  underbridge in the cyst. 
Heterodera  cynodontis (Nematoda : Heteroderidae)  parasite de Cynodon  dactylon (L.) au  Pakistan 
Heterodera cynodontis n.  sp.,  appartenant  au (( groupe goettingiana N et parasitant  les  racines  d‘une  graminée d pelouse, Cynodon 
dactylon (L.), à Karachi,  est  décrit et illustré.  Cette  nouvelle  espèce,  dépourvue  de  bullae, st proche  de H.  graminophila Golden 
& Birchfield,  1972, H. longicolla Golden & Dickerson,  1973, H. elachista Ohshima,  1974  et H. o y z a e  Luc & Berdon-Brizuela,  1961 
par  les  kystes  limoniformes,  l’absence  d’ornementation  périanale,  les  juvéniles  de  deuxième  stade (J2) comportant un champ  latéral 
à trois  lignes et un stylet ne dépassant  pas 22,5 pm  en  moyenne. H. cynodontis n.  sp.  diffère  de  ces  espèces  par  la  partie  terminale 
hyaline  de  la queue  des  J2  plus  courte, et un sous-pont  faiblement  développé  chez  le  kyste. 
In August, 1988 specimens of an undescribed cyst 
nematode  species  were  found  in  large  numbers  attached 
to the roots of lawn grass, Burmuda grass Cynodon 
dactylon L. in  the  garden of a residential  house in  North 
Nazimabad, Karachi, Pakistan. A pure culture of the 
species was established on lawn grass in  the greenhouse 
at  the  National Nematological  Research  Centre,  Univer- 
sity of Karachi. We herein  describe  this  nematode  as a 
new Heterodera species in  the “ goettingiana group ”. 
Materials  and  methods 
Specimens were fiied  in 3 Yo formaldehyde  solution 
and  mounted  in glycerine  (Seinhorst, 1959) on  the glass 
slide. The cover glass was supported by the wax. 
Measurements  were  made  with an ocular  micrometer, 
and drawings  were  prepared  with a drawing  tube. 
Photomicrographs of cysts, females, males and juveniles 
were made with an automatic camera attached to a 
compound microscope using Nomarski’s interference 
contrast. For  the  studies of the  embryonic  development 
mature females were selected. They were placed in a 
Revue Nérnatol. 12 (4) : 395-400 (1989) 
drop of water  on a slide and  the cuticle ruptured. A cover 
glass was placed over the cyst and  gentle pressure 
applied to the cover glass released eggs of different 
stages. 
Heterodera  cynodontis n. sp. 
(Figs 1-3) 
MEASUREMENTS* 
White  female (paratypes; n = 30) : L (excluding 
neck) = 408.0 k 59.38 (320.0-520.0); W = 307.0 k 
44.90 (224.0-376.0); neck  length = 121.6 & 28.50 
(80-160); stylet length = 20.8 f 0.81 (19.0-21.4). 
Cyst (n = 50); length (excluding neck) = 510.0 C 
L/W = 1.23 C 0.62  (1.15-1.36); fenestral  length 
= 52 k 6.32 (44-64); fenestral  width = 28.3 k 
4.16 (20-34); vulval  bridge  with = 7.2 f 1.02 
45.22 (440.0-568.0); W = 412.0 f 23.01 (350.0-440.0); 
* d l  measurements are in micrometers unless othenvise stated. 
395 
E Shahina C M. A. Maqbool 
(6.0-9.6); underbridge = 64 f 3.85 (60-70); Vulval slit 
= 36.4 f 2.1 1 (33-40); anus from posterior end = 
32.0 f 0.92 (30.0-35.0). 
M a l e  (n = 20); L = 784.5 f 43.87 (708.0-824.0); 
a = 38.24 f 3.183 (32.63-44.13); b = 5.22 f 0.39 
c’ = 0.48 f .O7 (0.35-0.58); stylet = 22.4 f 0.8 
(20.8-23.2); outlet of dorsal  esophageal  gland  from  base 
of stylet = 3.36 t 1.32 (2.4-4.0); spicules = 25.6 f 2.7 ’ 
(22.4-28.0); gubernaculum = 7.2 f 0.56 (6.4-8.0). 
Second stage juveniles (n = 25); L = 345.38 f 15.09 
(317.0-374.0); a = 17.7 & 0.92 (16.5-19.4); b = 
3.7 f 0.41 (3.3-4.6); stylet = 20.0 f 1.41 (19.2-20.8); 
tail  length = 45.7 f 2.46 (40.8-48.0); tail hyaline por- 
tion = 18.8 t 0.91  (16.0-20.0); tail  length/hyaline 
portion of tail = 2.42 f 0.20 (2.12-2.68). 
Eggs (n = 50); length = 92.8 f 2.53 (88-96); 
width = 38.8 -I- 1.41 (36-40); L/W ratio : 2.3 f 0.11 
(4.6-5.9); c = 150.3 f 32.15 (126.0-201.6); 
2.42 f 0.19 (2.1-2.8); c = 7.5 f 0.29 (7.2-8.0); C’ = 
(2.2-2.5). 
Holotype (female); L (excluding  neck) = 370.0; 
W = 270.0; neck length = 96.0; stylet length = 20.8. 
DESCRIPTION 
White  female : Body  pearly white, lemon  shaped  with 
protruding neck and vulva, neck expanding rapidly. 
Cuticle thick, 4.5 f 0.25 (3.5-5.0) at mid body with 
zig-zag  pattern, and subcuticular  punctations  present. 
Cuticle  annulated  in  anterior  region  and  concentric wavy 
lines  present  around vulval cone. Head distinctly  offset 
with a single  disc-shaped  annule.  Cephalic  sclerotization 
weak. Stylet delicate, with basal knobs sloping pos- 
teriorly. Outlet of dorsal esophageal gland 4 & 0.81 
(3.2-5.0) from base of stylet.  Median  esophageal bulb 
prominent, 20.8 2 0.10  ( 9.0-21.0) long  and 
17.6 f 0.12 (16.0-18.0) wide, with strongly developed 
valve plates. Esophageal glands appearing as a single 
lobe.  Excretory  pore  distinct,  located at position of the 
gland  lobe. Vulva conspicuous,  protruding  posteriorly. 
Egg sac  absent. Anus small, conspicuous. 
Cyst : Cysts  light to dark brown, lemon  shaped,  with 
protruding neck and vulva. Cuticular zig-zag pattern 
conspicuous,  irregularly  arranged  subcuticular  puncta- 
tion presen:. Egg sac  absent.  Cone  top  abullate,  ambife- 
nestrate; fenestral length 52 f 6.32 (44-64), fenestral 
width 28.3 f 4.16 (20-34). Semifenestrae  symmetrical, 
separated by a wide vulval bridge 7.2 & 1.02 (6.0-9.6) 
encircled by a wide  sclerotized  ark-brown  basin 
8.6 f 0.86 (8.0-10.0) wide;  underbridge weak but 
prominent, bifurcate at the ends, 64 f 3.85 (60-70) 
long. Vulval slit averaging  about 36.4 t 2.11 (33-40) in 
length. Anus small, conspicuous,  without surrounding 
396 
pattern  and situated  about 32.0 f 0.92 (30.0-35.0) from 
posterior  end. 
M a l e  : Males numerous; body cylindrical elongate, 
usually dorsally curved and gradually  tapering at each 
end. Cuticle distinctly annulated, annulations 1.6-2.4 
apart  at  mid-body.  Lateral  field about  1/4 body width 
with slight  areolation  appearing  sometimes  as  three  lines 
but  in many cases as four with the two inner lines much 
closer than the  outer ones, and  outer lines weakly 
crenate. Head broadly  hemispherical  with  four  or five 
annules, 8.0 f 0.8 (7.2-9.6) long  and 4 f 0.6 (3.2-5.0) 
wide, slightly set  off.  Cephalic  sclerotization heavy. 
Stylet well developed with slightly anteriorly directed 
knobs. Procorpus a slender tube ending in a distinct 
median  bulb, with prominent valve plates.  Esophageal 
glands  as a single lobe, with  three  nuclei,  overlaping  the 
anterior region of the intestine. Excretory pore, with 
prominent duct, 119.1 f 2.85 (116-124) from anterior 
end.  Hemizonid two or three  annules  anterior  to 
the  excretory  pore.  T stis single, outstretched 
415.0 f 29.14  (360.0-452.0) long.  Spicule  arcuate,  and 
finely  bidentate. Gubernaculum simple, cloacal opening 
protruding.  Phasmids  not  observed. 
Second stage juvenile : Body vermiform,  tapering at 
both  extremities but  much more so posteriorly.  Cuticle 
with  distinct  annulation, 1.6-2.4 pm wide at mid body. 
Lateral lines areolated and composed of three lines. 
Head slightly offset, 9.2 2 0.43 (8.8-9.6) pm wide and 
3.5 4 0.43 (3.2-4.0) pm high, with three annules. Ce- 
phalic  framework heavily sclerotized.  Stylet well devel- 
oped  with  prominent,  anteriorly  directed  knobs.  Dorsal 
esophageal  gland duct opens 5.6 f 0.8 (4.8-6.4) behind 
the base of the stylet. Median esophageal bulb ovoid 
with  strong valvular apparatus;  esophageal  glands elon- 
gate and overlapping the intestine laterally with three 
prominent  uclei.  Excretory  pore 76.6 f 4.25 
(70.0-80.0) pm  from anterior  end.  Hemizonid  more than 
two annules wide, 2-3 annules  anterior  to  the excretory 
pore. Genital  primordium two celled, 8.0 f 1.02 
(6.0-9.0) pm long. 4.0 & 0.82 (3.2-5.6) pm wide, 
179.2 f 9.59 (169.0-188.0) pm  from  the anterior end. 
Tai1 gradually  tapering,  conoid  with  rounded  terminus; 
hyaline terminal part unusually short. Phasmid very 
small, 32 k 1.02  (30-35) pm  anterior to tail  tip. 
Eggs : Embryonic  development basically the same as 
in  other species of Heterodera. One celled eggs with  large 
number of embryonic  granules and  prominent nucleus 
at centre.  Two celled eggs divided  transversely at right 
angles to longitudinal axis with blastomeres equal in 
size. Two celled eggs divide further transversely to  form 
three and four celled eggs. Some eggs with complete 
embryonic  development and  first stage juvenile present. 
Numerous egg  with  completely  development  and sp.ear 
beginning to  form  in second  stage juvenile. 
Revue Nématol. 12 (4) : 395-400 (1989) 
Heterodera  cynodontis n.sp. 
- C-G,I 
Fig. 1. Heterodera cynodontis n.  sp. - A-G Second  stage  juveniles. A : Entire; B : Oesophageal  region; C : Head; D, E : Tails; 
F, G : Tai1  terminus. - H-L Male.  H : Oesophageal  region; 1 : Head; J, K, L : Tails. - M  Female, anterior  region. 
Revue Nématol. 12 (4) : 395-400 (1989) 397 
l? Shahina Br M. A. Maqbool 
Fig. 2. Heterodera cynodontis n. sp. - A-D Female. A : White  females; B : Oesophageal  region;  C : Anterior  region  showing  single 
head annule  and  stylet; D : Cuticular  annulation  and  single head  annule. - E-L Cyst. E : Mature  cysts; F : Cyst  attached to the 
roots; G : Lateral view  of  vulva-cone  showing  underbridge; H : Underbridge  showing  bifurcate  ends; 1 : Vulval cone showing 
ambifenestrae; J : Fenestrae  indicating  edge of basin; K : Fenestrae  showing  vulval slit; L : Vulval  slit and  vulval  bridge,  magnifïed 
(Scale bar :A, E = 400 Fm; B = 50 Pm; GD, G-L = 25 Pm; F = 200 prn). 
398 Revue Né?natol. 12 (4) : 395-400  (1989) 
Heterodera  cynodontis n.sp. 
Fig. 3. Heterodera  cynodontis n.  sp. - A, B, C Cyst  Wall; A : Zig-zag  lines at nid body; B : Subcuticular  punctation; C : Zig-zag 
lines  and  subcuticular  punctation. - Dy E, F Male. D : Anterior  region; E : Four lateral  lines; F : Posterior  region. - G, H, 1 
Second  stage  juveniles. G : Anterior  region;  H : Three  lateral  lines; 1 : Tai1 and hyaline  portion &ale bars = 30 ~ d .  
Revue Nématol. 12 (4) : 395-400  (1989) 399 
F. Shahina di M .  A. Maqbool - 
TYPE SPECIMENS 
Holotype (female) : deposited in  the  NNRC National 
Nematode  Collection,  University of Karachi,  Karachi, 
Pakistan. 
Paratypes : 30  females, 100 cysts, 25 males,  250 juv- 
eniles and 100 eggs; deposited in  the  NNRC National 
Nernatode Collection, University of Karachi,  Karachi, 
Pakistan. 25  cysts, 15  females, 5 males and 25 juveniles 
deposited in  the  United  States  Department of Agricul- 
ture (USDA) Nematode Collection, Beltsville, Mary- 
land, USA. 
TYPE HOST AND LOCALITY 
Specimens  collected from soi1 and roots of Cynodon 
dactylon (L.) in August,  1988 from  the  North Nazima- 
bad,  Karachi,  Pakistan. 
DIAGNOSIS AND RELATIONSHIP 
Heteroderu  cynodontis nsp.  belongs to  the “ goettin- 
giunu group ” (bullae  rarely  present,  underbridge  either 
absent,  slender or strongly  developed vulva cone  ambi- 
fenestrate  or  bifenestrate). On  the basis of a combination 
of characteristics, H. cynodontis nsp .  can  be  separated 
from al1 the species of the “ goettingiuna group ” by 
lemon  shaped cyst, mean.L/W ratio 1.3, perianal  pattern 
absent, weak, smaller  underbridge, second stage juvenile 
with three incisures in the lateral fields, mean stylet 
length much less than 22.7, smaller  hyaline tail terminus 
length. 
H. cynodontis nsp .  comes close to H. granzinophila 
Golden & Birchfield, 1972, H. longicolla Golden & 
Dickerson, 1973, H. elachista Ohshima, 1974 and 
H. oryzae Luc & Berdon-Brizuela, 1961, with the lemon 
shaped cyst, rnean L/W ratio 1.3, perianal  pattern 
absent, lateral field of the second stage juvenile with 
three  incisures. It can  be distinguished from H. grunzi- 
nophila by the smaller  stylet of the female, the smaller 
fenestral  width and  shorter  underbridge  and vulval slit 
of the cyst, the  shorter  body  and  spicule of the  male and 
the shorter body, stylet, tail and hyaline  tail of the second 
stage juvenile (in H. graminophila : female stylet = 
21.3-23.8; fenestral  width = 43-50; underbridge 
= 115-140; vulval  slit = 40-52; male = 850- 
1,110; spicules = 31-36; second  stage juvenile = 
360-460; J2 stylet = 21.8-23.5; 52 tail = 57-67; 
hyaline tail = 25-38). H. cynodontis n.sp. differs from 
Accepté pour publication le 27 janvier 1989. 
H. longicolla by the smaller L/W ratio and single 
head annule of the female, the  presence of an  under- 
bridge, narrower  fenestral  and  shorter  vulval  slit and a 
strongly  developed vulval bridge in  the  cyst  and in the 
male;  greater “ a ”, smaller “ c ” and longer  stylet in  the 
male and  the longer stylet and smaller hyaline tail of 
the juvenile (in H. longicolla : female cyst L/W 
ratio = 1.5-2.7; underbridge  absent;  fenestral 
width = 40; vulval slit = 45; vulval  bridge weak; male 
a = 23-32; c = 215-1 580; male stylet = 17.9-20.2; 
juvenile stylet = 16.8-18.5; hyaline tail = 20-33). It can 
be  separated  from H. elachistu females by the absence 
of an egg sac; from cysts by the absence of bullae,  the 
longer  fenestra and semifenestra and  the shorter  under- 
bridge; from  the males by the smaller body length and ante- 
riorly directed stylet  knobs and  from  the juvenile by  the 
shorter hyaline tail  (in H. elachista : gelatinous egg-sac 
with eggs, and bullae present; fenestrae 25-37; semi- 
fenestrae = 9-17; underbridge = 75-90; male 
L = 820-940; stylet knobs sloping  posteriorly; J2 
hyaline tail = 26-36). H. cynodontis nsp. can be dis- 
tinguished from H. oryzae by the  shorter  stylet of the 
female, the absence of bullae, the longer  fenestrae  and 
shorter vulval slit and  underbridge; the smaller  stylet of 
the  male  with the stylet  knobs  directed  anteriorly and  the 
shorter juvenile with  tail and hyaline, tail without  elon- 
gate conical terminus (in H. oryzae : female stylet : 
28-30, bullae  present;  fenestral  length = 40-55; vulval 
slit = 42-50; underbridge = 110-150; male stylet = 
23-25 with  knobs  directing  posteriorly; J2, L = 
370-507; J2 tail = 67-69; hyaline tail = 35-45 with 
elongated  terminus and pointed  extremity). 
REFERENCES 
GOLDEN, A. M. & BIRCHFIELD, W. (1972). Heterodera grami- 
nophila nsp. (Nematoda : Heteroderidae)  from  grass  with 
a key of closely  related  species. J. Nematol, 4 : 147-154. 
GOLDEN, A. M. & DICKERSON, O. 1. (1973). Heterodera lon- 
gicolla n.sp.  (Nematoda : Heteroderidae)  from  Buffalo-grass 
(Buchloe dactyloides) in Kansas. J.  Nenzatol, 5 : 149-154. 
Luc, M. & BERDON-BRIZUELA, R. (1961): Heterodera oryzae 
n.sp. (Nematoda : Tylenchoidea) parasite du riz en Côte 
d’Ivoire. Nematologica, 6 : 272-279. 
OHSHIMA, Y.  (1974). Heterodera elachista nsp. an upland  rice 
cyst  nematode  from  Japan. Japanese J.  Nernatol, 4 : 51-56. 
SEINHORST, J. W. (1959). A rapid method for transfer of 
nematodes  from  fixative  to  anhydrous  glycerine. Nenzutolo- 
gica, 4 : 67-69. 
400 Revue Nénzatol. 12 (4) : 395-400  (1989) 


Heterodera cynodontis n. sp. (Nematoda : Heteroderidae) from Cynodon dactylon (L.) in Pakistan

Abstract

Similar works

Full text

Available Versions

Horizon / Pleins textes