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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Heterodera

Heterodera Schmidt, 1871 (ref. ID; 5922)

Suborder Tylenchina: Family Heteroderidae (ref. ID; 3547)

Family Heteroderidae (ref. ID; 5956, 6182, 7261)

ref. ID; 1923

Vulva and anus very closely approximated; body wall transformed to a persistent cyst. (A large genus of over 20 species) (ref. ID; 1923)

ref. ID; 5922

Diagnosis (emended from that of Wouts and Sher (1971))

Mature female and Cyst: With posterior protuberance (the vulval cone) more or less lemon-shaped; cuticle with lacelike pattern of ridgeds. Vulval slit short to long (10-60 µm); sited at apex of vulval cone; underbridge and bullae present or absent. Perineal tubercles (Mulvey 1973) absent. Vulval cone bifenestrate circum- or ambi-fenestrate. Anus dorsal, not on vulval lip. (ref. ID; 5922)
  • Second-stage Juvenile: Stylet less than 30 µm. Esophageal glands fill body width. Phasmids without lenslike structure in muscle layer. (ref. ID; 5922)
  • Male: To 1.5 mm in length. Labial disc present but with low profile. Tail present, length less than half body width. (ref. ID; 5922)

    Type species

    Heterodera schachtii Schmidt, 1871 (ref. ID; 5922)

    ref. ID; 6691, 6859

    Plant parasite. (ref. ID; 6691, 6859)
    1. Heterodera achilleae Golden & Klindic, 1973
      See; Globodera achilleae (ref. ID; 5922)
    2. Heterodera amaranthi Stoyanov, 1972 (ref. ID; 5922)
    3. Heterodera aquatica Kir'janova, 1971 (ref. ID; 5922)
    4. Heterodera arenaria Cooper, 1955 (ref. ID; 5922)
    5. Heterodera artemisiae Eroshenko & Kasachenko, 1972
      See; Globodera artemisiae (ref. ID; 5922)
    6. Heterodera avenae Wollenweber, 1924 (ref. ID; 5922)
    7. Heterodera betulae Hirschmann & Riggs, 1969 (ref. ID; 5922)
    8. Heterodera bifenestra Cooper, 1955 (ref. ID; 5922)
    9. Heterodera cacti Filipjev & Schuurmans Stekhoven, 1941 (ref. ID; 5922)
    10. Heterodera cajani Koshy, 1967 (ref. ID; 5922)
    11. Heterodera cardiolata Kir'janova & Ivanova, 1969 (ref. ID; 5922)
    12. Heterodera carotae Jones, 1950 (ref. ID; 5922)
    13. Heterodera chaubattia Gupta & Edward, 1973 (ref. ID; 5922)
    14. Heterodera cruciferae Franklin, 1945 (ref. ID; 5922)
    15. Heterodera cyperi Golden, Rau, and Cobb, 1962 (ref. ID; 5922)
    16. Heterodera elachista Oshima, 1974 (ref. ID; 5922)
    17. Heterodera estonica Kir'janova & Krall, 1963 (ref. ID; 5922)
    18. Heterodera fici Kir'janova, 1954 (ref. ID; 5922)
    19. Heterodera galeopsidis Goffart, 1936 (ref. ID; 5922)
    20. Heterodera glycines Ichinohe, 1952 (ref. ID; 5922)
    21. Heterodera goettingiana Liebscher, 1892 (ref. ID; 5922)
    22. Heterodera graduni Kir'janova in Kir'janova & Krall (1971) (ref. ID; 5922)
    23. Heterodera graminis Stynes, 1971 (ref. ID; 5922)
    24. Heterodera graminophila Golden & Birchfield, 1972 (ref. ID; 5922)
    25. Heterodera hordecalis Andersson, 1975 (ref. ID; 5922)
    26. Heterodera humuli Filipjev, 1934 (ref. ID; 5922)
    27. Heterodera indocyperi Husain & Kahn, 1964 (ref. ID; 5922)
    28. Heterodera iri Mathews, 1971 (ref. ID; 5922)
    29. Heterodera latipons Franklin, 1969 (ref. ID; 5922)
    30. Heterodera leptonepia G.S. Cobb & Taylor, 1953
      See; Globodera leptonepia (ref. ID; 5922)
    31. Heterodera lespedezae Golden & Cobb, 1963 (ref. ID; 5922)
    32. Heterodera leuceilyma Di Edwardo & Perry, 1964 (ref. ID; 5922)
    33. Heterodera limonii Cooper, 1955 (ref. ID; 5922)
    34. Heterodera longicaudata Seidel, 1972 (ref. ID; 5922)
    35. Heterodera longicolla Golden & Dickerson, 1973 (ref. ID; 5922)
    36. Heterodera mali Kir'janova & Borisenko, 1975
      See; Globodera mali (ref. ID; 5922)
    37. Heterodera mani Mathews, 1971 (ref. ID; 5922)
    38. Heterodera medicaginis Kir'janova in Kir'janova & Krall (1971) (ref. ID; 5922)
    39. Heterodera methwoldensis Cooper, 1955 (ref. ID; 5922)
    40. Heterodera millefolii Kir'janova & Krall, 1965
      See; Globodera millefolii (ref. ID; 5922)
    41. Heterodera mirabile Kir'janova, 1971
      See; Globodera mirabile (ref. ID; 5922)
    42. Heterodera mothi Khan & Husain, 1965 (ref. ID; 5922)
    43. Heterodera oryzae Luc & Berdon-Brizuela, 1961 (ref. ID; 5922)
    44. Heterodera oxiana Kir'janova, 1962 (ref. ID; 5922)
    45. Heterodera paratrifolii Kir'janova, 1963 (ref. ID; 5922)
    46. Heterodera pallida Stone, 1973
      See; Globodera pallida (ref. ID; 5922)
    47. Heterodera polygoni Cooper, 1955 (ref. ID; 5922)
    48. Heterodera pseudorostochiensis Kir'janova, 1963
      See; Globodera pseudorostochiensis (ref. ID; 5922)
    49. Heterodera rosii Duggan & Brennan, 1966 (ref. ID; 5922)
    50. Heterodera rostchiensis Wollenweber, 1923 (ref. ID; 5922) reported author and year? (ref. ID; 7621)
      See; Globodera rostochiensis (ref. ID; 5922)
    51. Heterodera rumicis Pogosyan, 1961 (ref. ID; 5922)
    52. Heterodera sacchari Luc & Merny, 1963 (ref. ID; 5922)
    53. Heterodera salixophila Kir'janova, 1969 (ref. ID; 5922)
    54. Heterodera schachtii Schmidt, 1871 (ref. ID; 7261) reported year? (ref. ID; 6569) reported author and year? (ref. ID; 3547, 7241)
    55. Heterodera scleranthii Kaktyna, 1957 (ref. ID; 5922)
    56. Heterodera solanacearum Miller & Gray, 1972
      See; Globodera solanacearum (ref. ID; 5922)
    57. Heterodera sonchophila Kir'janova & Borozdina in Kir'janova (1969) (ref. ID; 5922)
    58. Heterodera tabacum Lownsbery & Lownsbery, 1954
      See; Globodera tabacum (ref. ID; 5922)
    59. Heterodera tadschikistanica Kir'janova & Ivanova, 1966 (ref. ID; 5922)
    60. Heterodera trifolii Goffart, 1932 (ref. ID; 5922)
    61. Heterodera turcomanica Kir'janova & Shagalina, 1965 (ref. ID; 5922)
    62. Heterodera urticae Cooper, 1955 (ref. ID; 5922)
    63. Heterodera ustinovi Kir'janova, 1969 (ref. ID; 5922)
    64. Heterodera vigni Edward & Misra, 1968 (ref. ID; 5922)
    65. Heterodera virginiae Miller & Gray, 1968
      See; Globodera virginiae (ref. ID; 5922)
    66. Heterodera weissi Steiner, 1949 (ref. ID; 5922)
    67. Heterodera zeae Koshy, Swarup, and Sethi, 1971 (ref. ID; 5922) reported author and year? (ref. ID; 3547)

    Heterodera schachtii Schmidt, 1871 (ref. ID; 7261) reported year? (ref. ID; 6569) reported author and year? (ref. ID; 3547, 7241)

    Descriptions

    Second-stage juvenile: Fine structure of the phasmid. The phasmid of infective second-stage juveniles of H. schachtii includes an external pore, cuticle-lined duct, socket cell, sheath cell, and a single dendrite receptor, but specimens examined varied in phasmid detail and two discrete types could be recognized. One type of phasmid, arbitrarily designated A, was larger and more complex relative to another named B. The diminutive B phasmid was most common, occurring in about two-thirds of the specimens examined. The type was usually consistent between the two phasmids of a give individual. The phasmid pore opens in the center of the lateral field midway between the anus and hyaline tail terminus. The opening is about 0.1 µm in diameter and the lumen of the duct, which is about 2.5 µm long, broadens as it penetrates the basal layer of the body wall cuticle. Proximally, the duct is irregularly shaped with distended and collapsed regions. The lining of the duct is continuous with the external cortex of the body wall cuticle, although proximally it is thinner and appears to be increasingly osmophilic. The lining terminates near the junction of the socket and sheath cells. The lumen of the duct typically contains electron-dense material which forms a plug near the external opening. In the A phasmid, similar material accumulates at the proximal end of the duct as well. The socket cell of both types of phasmids is about 5 µm long; it is roughly cup shaped with a thickened base and envelops the duct. The inner surface of the cup partially encloses the posterior end of the sheath cell. Anterior to the duct the socket cell forms a layer of varying thickness which partly envelops the sheath cell, but it again broadens near its anterior terminus where there is a large nucleus. In the A phasmid the socket cell is relatively broad and includes abundant ribosomes (about 24 nm diameter) and electron dense deposits; some denser deposits apparently accumulate at the plasmalemma adjacent to the duct. In the type B phasmid, however, the socket cell contains few dense deposits or organelles and is reduced in size. The sheath cell fills the cup of the socket cell near the proximal end of the duct. It is about 10 µm long and extends anteriorly where it includes a nucleus within ganglia of the retaol commissure. Posteriorly, junctional complexes occur between the socket and sheath cells, and portions of the socket cell project into invaginations of the sheath cell. In the A phasmid the plasmallemma of the sheath cell is invaginated, forming a receptor cavity at the proximal end of the duct. The receptor cavity is deeply infolded, resulting in a maze of extracellular channels throughout the posterior half of the sheath cell. The channels are filled with moderately electron-dense material, which also fills the receptor cavity and appears to be continuous with content of the duct. The cytoplasm of the A sheath cell is electron dense with numerous ribosomes, including many which line the surface of the plasmalemma adjacent to the channels. Conversely the sheath cell of the B phasmid is diminutive with relatively electron-lucent cytoplasm, bundles of hexagonally arranged microtubules (about 22 nm diameter), at least one large vacuole, and few organelles. The greatly reduced folds of the plasmalemma adjacent to the duct are collapsed and there is no receptor cavity. The sheath cell encloses a single dendrite process which, in the A phasmid, terminates within the receptor cavity; the dendrite process does not extend into the duct. The distal terminus has few microtubules, but slightly anteriorly there is a ciliary region composed of a circle of eight doublets and three or four central singlets. A typical basal body was not observed; however, in some cases attachment between doublets was faintly resolved, suggesting a ciliary necklace. Rootlets were not observed in longitudinal or cross sections, although amorphous dense material occurs in the cytoplasm of the receptor process. The dendritic process has an irregularly shaped boundary which forms junctional complexes with the sheath cell. The dendrite is about 16 µm long, and the perikaryon, including the nucleus, is located adjacent to the rectal dilator musculature, in ganglia anterior to the rectal commissure. The dendrite of the B phasmid, although similar to A, is generally reduced in diameter. Since the receptor cavity is absent, the distal end of the dendrite is closely enclosed by the sheath cell, so there is little direct contact between the dendrite and extracellular space of the duct. (ref. ID; 7241)

  • Male: Male has a single cylindrical telogonic testis that extends from the cloaca at the posterior terminus to the midbody. The gonad wall is a single layer of epithelial cells enclosed by a basal lamina. (ref. ID; 7261)
  • Sperm: Anteriorly the epithelium of the gonad wall is thin and the cytoplasm dense, whereas in the middle and posterior regions it is variable in thickness and the epithelial cells are typically enlarged by the accumulation of several electron-lucent membrane-bound vesicles. Each vesicle may enclose several small spherical electron dense granules. The testis lacks closely associated bundles of intestinal fibers (fasciculi). Preadult and young males of H. schachtii typically have only spermatids and immature sperm, whereas the testes of older males are filled with mature spermatozoa. Young spermatids are mostly elongate unattached cell about 2.5x4.5 µm, rarely with pseudopodia (robust cytoplasmic projections) and filopodia (long, slender, fingerlike projections). Bundles of parallel fibrils organized within membrane-bound pockets, the fibrous bodies, are obscure at this stage, but as spermatids mature they increase in clarity and number. In young spermatids, mitochondria tend to be concentrated near the plasmalemma. Nuclear material, that is membraneless compacted chromatin, occurs near the center of the cell. As spermatids mature they become polarized so that the chromatin and organelles are concentrated at one end of the cytoplasm; the opposing end is finally eliminated as a residual body. Maturing sperm of H. schachtii remain closely packed and filopodia increase in numbers, interdigitating with one another within the vas deferens. Young sperm contain many fibrous bodies that gradually degrade and are lost in mature sperm. Mature sperm vary in shape from spherical to irregular; they are about 4-10 µm in diameter, with many filopodia concentrated on one side of the cell. No polarization in the distribution of organelles was observed in sperm within the testis, and mitochondria and condensed chromatin remain unchanged in form from those present in spermatids. In H. schachtii a single layer of cortical microtubules lines the inner surface of the sperm plasmalemma. In seminated females of H. schachtii, sperm are tightly packed within the enlarged spermatheca. Sperm mitochondria are concentrated around the central compact chromatin but are absent in pseudopodia. Pseudopodia of each sperm bulge into those of neighboring sperm and cell-to-cell attachments occur between sperm and the spermatheca epithelium. Even distant sperm are anchored to epithelial cells with long robust pseudopodia and apparently are not displaced when oocytes move through the spermatheca. (ref. ID; 7261)

    Remarks

    Heterodera schachtii (Schmidt) is a plant-parasitic nematode commonly found on the sugar beet, Beta vulgaris L. Females form immobile egg-producing cysts still attached to the host, whereas male worms become free-living in the soil and seek out mating partners. (ref. ID; 6569)

    Examined materials

    Heterodera schachtii was isolated from sugar beet (Beta vulgaris L.) in California. (ref. ID; 7261)