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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Meloidogyne

Meloidogyne Goeldi, 1887 (ref. ID; 7194)

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

Family Meloidogynidae (ref. ID; 5955)

Family Heteroderidae (ref. ID; 6182)

ref. ID; 1923

Females pear-shaped, body wall not modified, but cuticle with involved striation patterns; vulva terminal near anus; males with lateral cheeks and without numerous cephalic striae. (ref. ID; 1923)

ref. ID; 6153

Herbivores. (ref. ID; 6153)

ref. ID; 7194

Whitehead (1968) emphasized the taxonomic importance of the perineal pattern (posterior cuticular pattern of the female) in the separation of species belonging to the root-knot genus Meloidogyne Goeldi, 1887. (ref. ID; 7194)
  1. Meloidogyne acronea Coetzee, 1956 (ref. ID; 7194)
  2. Meloidogyne arenaria (Neal, 1889) Chitwood, 1949 (ref. ID; 1771)
  3. Meloidogyne deconincki Elmiligy, 1968 (ref. ID; 7194)
  4. Meloidogyne graminicola Golden and Birchfield, 1965 (ref. ID; 5955)
  5. Meloidogyne graminis (Sledge and Golden, 1968) Whitehead, 1968 (ref. ID; 5955), (Siedge and Golden, 1964) Whitehead, 1968 (ref. ID; 7194)
  6. Meloidogyne hapla Chitwood, 1949 (ref. ID; 1771, 7194)
  7. Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (ref. ID; 1771, 7194) reported author and year? (ref. ID; 3547)
  8. Meloidogyne javanica (Treub, 1885) Chitwood, 1949 (ref. ID; 1771)
  9. Meloidogyne naasi Franklin, 1965 (ref. ID; 5955)
  10. Meloidogyne oryzae Maas, Sanders and Dede, 1978 (ref. ID; 5955)
  11. Meloidogyne sewelli Mulvey & Anderson, 1980 (ref. ID; 5955 original paper)
  12. Meloidogyne spartinae (Rau and Fassuliotis, 1965) Whitehead, 1968 (ref. ID; 5955)

Meloidogyne hapla Chitwood, 1949 (ref. ID; 1771, 7194)

Descriptions

Perineal morphology: Dorsal and ventral striae of the perineal pattern of M. hapla and M. incognita are revealed with light interference and scanning electron microscopy. The dorsal and ventral striae of M. incognita are interrupted and forked at the lateral line, whereas those of M. hapla present a regular line of demarcation separating the dorsal and ventral areas. Some specimens of M. hapla have a distinct loop or wing along which the dorsal striae abut at right angles. When present, this wing is generally located to the left of the vulva but may be present on both sides (Taylor et al. 1955). Scanning electron micrographs provide a three-dimensional impression and reveal in both species that the dorsal and ventral striae are composed of bundles of tightly compressed annules. Scanning photomicrographs show that the vulva of M. hapla and M. incognita is located in a distinct depression whereas light microscopy shows only that the vulva is not in the same focal plane as the surrounding cuticular striae. The perineal pattern of M. hapla, as revealed by scanning microscopy, is characterized by a distinct invagination of the cuticle between the vulva and the lateral stria near which the anus is located. Light microscopy shows only a conspicuous curved line between the anus and the vulva that suggests a superficial infolding. This perineal characteristic is not present in M. incognita. Franklin (1965) has described a similar invagination and anal position for M. naasi. A number of light photomicrographs of other Meloidogyne spp. also show a conspicuous curved line with the anus adjacent but in a different focal plane, suggesting a similar invagination. These other species include M. graminis (Siedge and Golden, 1964), Whitehead, 1968; M. acronea Coetzee, 1956; M. deconincki Elmiligy, 1968; and M. graminicola Golden and Birchfield, 1965. In M. hapla perineal patterns, stippling or punctation appears with light microscopy as dot-like markings concentrated in an area immediately dorsad of the anus. This punctation was not evident on scanning electron micrographs and is therefore considered to the subcuticular. Whitehead (1968) found this punctation always present in the many specimens of M. hapla that the examined and we concur with his findings, havig examined several hundred females from various areas of Canada. Scanning electron microscopy is a necessary adjunct to light microscopy in the study and interpretation of the perineal pattern structures of Meloidogyne spp., as characters were revealed by scanning microscopy that had been previously obscure with conventional light microscopy. Both interference light and scanning electron microsocpy provided photomicrographs of greater clarity than conventional light microscopy. (ref. ID; 7194)

Examined material

Mature females were obtained from celery grown in a greenhouse at the Research Station, Vineland Station, Ontario, and from red clover from a field in Prince Edward Island. (ref. ID; 7194)

Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (ref. ID; 1771, 7194) reported author and year? (ref. ID; 3547)

Descriptions

Perineal morphology: See the description of M. hapla. (ref. ID; 7194)

Examined materials

Females were obtained from tomato in a greenhouse in Ottawa, Ontario; this root-knot nematode originated from potato from Cuba. (ref. ID; 7194)

Meloidogyne sewelli Mulvey & Anderson, 1980 (ref. ID; 5955 original paper)

Diagnosis

Meloidogyne sewelli n. sp. differs from all other described species of root-knot nematodes by its perineal pattern, which is weakly etched or indistinct as opposed to being prominently etched. Length of second stage larva relate M. sewelli n. sp. most closely to the following: M. graminis (Sledge and Golden, 1968) Whitehead, 1968; M. graminicola Golden and Birchfield, 1965; M. oryzae Maas, Sanders and Dede, 1978; M. naasi Franklin, 1965; M. spartinae (Rau and Fassuliotis, 1965) Whitehead, 1968. It differs from these species by the more posterior position of the dorsal esophageal gland orifice (7-8 µm below stylet versus less than 7 µm). It is further differentiated from M. graminis, M. graminicola, and M. naasi in having an inflated rectum versus not inflated and from M. graminis and M. oryzae by the dorsal arch of the perineal pattern (rounded in M. sewelli versus a high arch). (ref. ID; 5955)

Descriptions

  • Female: Body pearly white, globular to pear shaped, without a posterior protuberance. Cuticule thin, 2-3 µm thick at midbody. Stylet slender, knobs small, rounded. Excretory pore usually slightly posterior to base of stylet. Perineal pattern often indistinct with rounded dorsal arch and many discontinuous, closely spaced striae. Phasmids large, closely spaced. Tail terminus marked by striae. Egg sac attached to mature female, two to three times size of female and containing several hundred eggs. Egg shell hyaline, without markings. (ref. ID; 5955)
  • Male: Head slightly set off, head cap prominent in dorsoventral view, head annules two or three, weakly defined. Lateral field with four incisures, not areloated. Stylet knobs rounded. Cephalids not observed. Excretory pore 40-50 µm posterior to centre of median bulb, 83-92 µm from anterior end of body. Testis outstretched. Spicules arcuate, tips bluntly rounded. Gubernaculum short, linear. Tail short, distinctively subdigitate. (ref. ID; 5955)
  • Second stage larva: Head slightly set off from body, bearing two or three faint annules, oral disc poorly delineated, amphids cylindroid, large, about four times length of oral opening. Stylet slender with median sized knobs. Orifice of dorsal esophageal gland 7-8 µm below stylet. Centre of median bulb 70(68-72) µm from anterior extremity, excretory pore 15-24 µm posterior to centre of median bulb. Hemizonid not observed. Lateral field with four incisures, not areolated. Rectum always inflated. Phasmid small, 10-15 µm posterior to anus. Tail long, tapering to narrowly rounded terminus. (ref. ID; 5955)
  • Gall: Numerous on most spike-rush plants on land. Length 1.5-4.0 mm, containing from 2 to 10 females and about an equal number of males, and with third and fourth stage larvae. (ref. ID; 5955)

    Etymology

    Meloidogyne sewelli n. sp. is named in honour of Mr. Robert Sewell. (ref. ID; 5955)

    Type host and locality

    Roots of spike-rush Eleocharis acicularis (L.) R & S, at the shore of the Ottawa River on the outskirts of Deschenes, Quebec, Canada. Collected by Mr. Robert Sewell on August 11, 1979. (ref. ID; 5955)

    Type designations

    Holotype (female), type slide No.248, collection No.7328. Allotype (male) type slide No.248a, collection number for Holotype. Paratypes (males, females, larvae and perineal patterns), distributed as follows: Canadian National Collection of Nematodes, Ottawa, Canada: United States Department of Agriculture Nematode Collection, Beltsville, Maryland. (ref. ID; 5955)

    Measurements

  • Holotype: Length (precluding neck) 490 µm, width 350 µm, neck length 115 µm, stylet length 15 µm, dorsal esophageal gland orifice 7 µm below stylet. (ref. ID; 5955)
  • Paratypes (20 females): Length (precluding neck) 442(410-510) µm, width 266(200-350) µm, neck length 93(70-115) µm, stylet length 14.5(14.0-15.0) µm, width of stylet knobs 3.5-4.0 µm, dorsal esophageal gland orifice 7-8 µm below stylet, vulva length 23-29 µm, vulva-anus distance 15-17 µm, eggs (n=20) 93(85-100) µm x 42(40-45) µm. (ref. ID; 5955)
  • Allotype (male): Length 1.5 mm, a=42, b=8.0, c=90, stylet length 18 µm, dorsal esophageal gland orifice 5 µm below stylet, spicule length 30 µm, gubernaculum length 8 µm. (ref. ID; 5955)
  • Paratype (20 male in lactophenol): Length 1.40(1.20-1.65) mm, a=40(36-44), b=7.9(7.5-8.3), c=80-92, stylet length 19(18-20) µm, diameter of stylet knobs 4 µm, dorsal esophageal gland orifice 5-6 µm below stylet, spicule length 29(28-30) µm, gubernaculum length 8-9 µm, tail length 15-18 µm, subdigitate. (ref. ID; 5955)
  • Second stage larva (40, in lactophenol mounts): Length 505(460-540) µm, width 13-15 µm, a=39(37-41), b=2.9(2.8-3.2), c=7.3(6.6-7.9), tail length 74(68-78) µm, head extremity to base of esophageal glands 177(168-190) µm, stylet length 12(11-13) µm. (ref. ID; 5955)
  • Second stage larva (10, in water mounts: Length 553(480-600) µm, width 13-15 µm, a=36(32-42), b=?, c=7.6(6.8-8.0), tail length 76(70-82) µm, stylet length 11-12 µm. (ref. ID; 5955)