Heterodera goettingiana 

 

Contents

 

Rev 11/26/2019

Pea Cyst Nematode Classification Hosts
Morphology and Anatomy Life Cycle
Return to Heterodera Menu Economic Importance Damage
Distribution Management
Return to Heteroderidae Menu Feeding  References
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Classification:

Tylenchida
 Tylenchina
  Tylenchoidea
   Heteroderidae
    Heteroderinae

     Heterodera goettingiana Liebscher, 1892

Synonyms:

H. schachtii (pea strain) Liebscher, 1890
H. (Heterodera) goettingiana Liebscher, 1892 (Skarbilovich, 1959)
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Morphology and Anatomy:

Male: Vermiform, with a very short, bluntly rounded tail. Body adopting a characteristically curved position on heat relaxation, the posterior part often twisting through 90 degrees about the long axis.

Cuticle regularly annulated, 4 incisures in lateral field, appears un-areolated under the light microscope, but is so SEM.

Head offset with prominent head cap and 5 to 6 annules. Head skeleton hexaradiate, heavily sclerotized. Anterior and posterior cephalids at level of second and eighth to ninth body annules, respectively.

Well developed stylet, anterior portion 45% of total stylet length, knobs rounded with anterior faces sloping backward. Stomal lining forming a lyre-shaped tube around stylet shaft, extending from basal plate of head skeleton for 60% of stylet length.

Median esophageal bulb a slender ellipse with prominent crescentic valve plates.

Dorsal and sub-ventral esophageal gland lobes distinct, both lobes extending beyond excretory pore, but subventral lobe longer, extending to 15% of body length from head. Dorsal gland nucleus prominent, sub-ventral gland nuclei obscure.

Broad nerve ring encircling esophagus between median bulb and gland lobes.

Hemizonid distinct, 2 annules long, usually 5-7 annules anterior to excretory pore, but in one specimen, it was only 1 annule anterior to the excretory pore. Hemizonion not seen.

Testis single, about 50% of total body length, packed with dense, spherical sperm and terminating in a glandular-walled vas deferens with narrow lumen.

Cloacal aperture small, surrounded by a raised collar-like lip.

Spicules stout, curved with inner faces reflexed inward and interlocked proximally to form a tube. Spicule tips broad and said to be tridentate by many authorities, but this character is difficult to resolve with light microscope, and electron microscope studies indicate that the spicules have bidentate tips. Gubernaculum a simple rod.

Phasmids and caudalids not observed.

Female: Body swollen, lemon-shaped, with projecting neck containing the esophagus and part of esophageal glands, bearing the head with one to three projecting head annules. Anterior part of neck irregularly annulated, remainder of body without annulations or lateral incisures, but covered with reticulate ridges forming a brickwork-like pattern. Head skeleton weak, hexaradiate.

Anterior part of stylet about 50% of stylet length and often detached in preserved specimens, stylet knobs rounded. Stomal lining forming a complex, lyre-shaped tube around stylet shaft, extending back from basal plate of head skeleton for 70% of stylet length.

Median esophageal bulb large, sub-spherical, with prominent oval valve.

Esophageal glands in broad lobe, often displaced by massively developed paired ovaries.

Prominent excretory pore at base of neck.

Vulva and tail region carried on an obtuse cone-shaped projection opposite the neck, the vulva a transverse slit surrounded dorsally and ventrally by thin-walled crescent shaped areas leaving the vulva on a thicker-walled bridge-like structure. Vagina supported proximally by strongly developed lateral bands of muscle. Fenestral region surrounded by a zone of thickened cuticle. The fenestral region is at the posterior pole of the body with the anus in a dorsal position.

Females are white on emergence from the root cortex and remain so throughout their development, turning brown at death. Females produce a gelatinous egg sac, exuded through the vulval aperture, into which some individuals lay a few eggs (Jones, 1950).

Cyst: Lemon-shaped with protruding neck and vulval cone, but irregularly formed specimens are common. Ambifenestrate. Vulval region may be intact in new cysts, but in older specimens, the thin-walled cuticle of the terminal region is lost, leaving an open fenestra crossed by a vulval bridge bearing the vulval slit and dividing the fenestra into two semi-circular semifenestrae. The lateral muscles attaching the proximal part of the vagina to the body wall remain as an underbridge and the vagina remains as a sheaf-like structure between the vulval bridge and underbridge.

Cyst wall dark brown and tough, with a thickened, strongly pigmented zone surrounding the fenestra. Bullae absent. Cyst wall bearing ridges forming a reticulate brickwork-like pattern. Subcrystalline layer not visible under light microscope, but a very fine layer is apparent with SEM. The egg sac is usually lost from cysts recovered from soil.

Second-stage juvenile: Folded 3 times in egg. Vermiform, with regularly annulated cuticle, 4 incisures in lateral field along most of body, reduced to 3 at anterior and posterior.

Lateral field appears un-areolated under the light microscope, but is so in the SEM. Cuticle thicker for first 7-8 body annules.

Head slightly offset with 2-3 annules, a dorsoventrally elongate oral disc and lateral lips bearing amphid apertures--these characters are shown by SEM. Head skeleton massive, hexaradiate, often obscuring stylet tip. Cephalids at second and eighth annules behind head.

Stylet robust, knobs varying from smoothly rounded to slightly hook-shaped with recurved anterior surfaces. Stomal lining forming a lyre-shaped tube around stylet shaft extending from basal plate of head skeleton for about 60% of stylet length.

Anterior part of esophagus as in male. Esophageal glands in an elongate lobe, extending for 33% to body length from head; broad posteriorly, dorsal gland and sub-ventral gland lobes less distinct than in male, but distinguishable by texture; both lobes extend beyond excretory pore. Dorsal gland nucleus prominent, sub-ventral gland nuclei indistinct.

Nerve ring as in male. Hemizonid 2 annules wide, 1 annule anterior to excretory pore. Hemizonion less than 1 annule wide, 7 or 8 annules behind excretory pore.

Genital primordium a distinct two-celled structure about half-way along body.

Tail tapering uniformly to a finely rounded terminus, posterior 60% of tail hyaline. Hyaline portion of tail often seen to contain 1 or 2 minute refractive bodies of unknown composition. Caudalids and phasmids not observed.


Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

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Distribution:

 Europe, Soviet Union, and limited areas in the United States.

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Economic Importance:

A-rated pests in California.

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Feeding:

Feeding site establishment and development typical of genus.

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Hosts:

Pea (3 species), bean (17 species), vetch, and a number of weeds.

 

For an extensive host range list for this species, click

 

 

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Life Cycle:

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click If species level data are not available, click for genus level parameters

Development and basic biology are similar to those of other cyst-nematodes.

The first molt occurs in the egg.

Second-stage juveniles are the invasive stage, entering host plant roots and passing through three more molts to the adult stage.

Males emerge from the host roots, but females remain, rupturing the root cortex as they enlarge and often remaining partly buried in the root tissue, especially in the thick main roots of beans.

H. goettingiana is amphimictic, and there is some evidence for environmental influence on sex ratio. In pot tests on pea, Pi of 4 eggs/g soil resulted in a population that was 50% females; P of 359 eggs/g soil resulted in less than 1% females.

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Damage:

Reduced root growth, water stress, suppression of nitrogen-fixing nodules, yellow foliage.

Numerous authors give evidence for extreme persistence of the nematode in the absence of a host crop, with crop damage still occurring after breaks of 10-12 years.

 

Pea crop infested by Heterodera goettingiana; patches of stunted and chlorotic plants.

Photograph from Di Vito (1991)

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Management:

Nematicides, crop rotation, and heat sterilization of soil used for pot experiments are effective.

Host Plant Resistance, Non-hosts and Crop Rotation alternatives:

For plants reported to have some level of resistance to this species, click

 

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References:

CIH Descriptions of Plant-parasitic Nematodes, Set 4, No. 47 (1972)

Di Vito, M. 1991.The pea cyst nematode, Heterodera goettingiana.  Nemtology Circ. 188, Florida Dept of Agriculture.

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Copyright © 1999 by Howard Ferris.
Revised: November 26, 2019.