Morphologic and Genetic Evidence for Mixed Infection with Two Myxobolus Species (Myxozoa: Myxobolidae) in Gray Mullets,Mugil cephalus,from Korean Waters

The present study was performed to trace the decisive evidence for mixed infection of 2 Myxobolus species, M. episquamalis and Myxobolus sp., in the gray mullet, Mugil cephalus, from Korean waters. Mullets with whitish cyst-like plasmodia on their scales were collected near a sewage plant in Yeosu, southern part of Korea, in 2009. The cysts were mainly located on scales and also found in the intestine. The spores from scales were oval in a frontal view, tapering anteriorly to a blunt apex, and measured 7.2 µm (5.8-8.0) in length and 5.3 µm (4.7-6.1) in width. Two polar capsules were pyriform and extended over the anterior half of the spore, measuring 3.5 µm (2.3-4.8) in length and 2.0 µm (1.5-2.2) in width. In contrast, the spores from the intestine were ellipsoidal, 10.4 µm (9.0-11.9) in length and 8.4 µm (7.3-10.1) in width. The polar capsules were pyriform but did not extend over the anterior half of the spore, 3.7 µm (2.5-4.5) in length and 2.2 µm (1.8-2.9) in width. The nucleotide sequences of the 18S rDNA gene of the 2 myxosporean spores from scales and intestine showed 88.1% identity to each other and 100% identity with M. episquamalis and 94.5% identity with M. spinacurvatura from mullet, respectively. By the above findings, it is first confirmed that mullets from the Korean water are infected with 2 myxosporean species, M. episquamalis and Myxobolus sp.     

Aphelenchoides microstylus n. sp. and Seinura onondagensis n. sp. (Nemata: Aphelenchina) from New York

Aphelenchoides microstylus n. sp. and Seinura onondagensis n. sp., a nematode predator, are described from dead Scots pine (Pinus sylvestris L.) in Onondaga County, New York. Females of A. microstylus are 370 to 485 µm long. The body is slender and tapers posteriorly to an amucronate, pointed terminus. The head is continuous with the body, and lips bear a stylet guide. Diagnostic characters of females are three incisures in the lateral field, a short stylet (6-7.5 µm) with small basal knobs, a single row of oocytes, and a long postuterine sac (25-50 µm). Males are characterized by small spicules (10-11µm); two pairs of post-anal, subventral papillae; and a single row of spermatocytes. A bursa and gubernaculum are absent. Seinura onondagensis females are characterized by a body of moderate length (475-595 µm), finely annulated cuticle, and a slightly set-off head. Diagnostic characters are four incisures in the lateral field, long stylet without basal knobs (17-22 µm), single row of oocytes, and presence of a postuterine sac (14-38 µm). Males are unknown. The monospecific genus Indaphelenchus is proposed as a synonym of Seinura, and S. siddiqii n. comb. is proposed for the only species, I. siddiqii.     

Two New Species of Actinolaimidae Thorne, 1939 (Nemata: Dorylaimida) from China

Two new species of Actinolaimidae are described from China. Trachactinolaimus brevicaudatus n. sp. is 3.4-4.4 mm long; a = 40-60, b = 3.5-5.2, c = 20-21 in female and 34-39 in male; odontostyle length is 29-33 µm; spicules are 67-77 µm long; and the stoma has four onchia with numerous mural denticles. The female has a longitudinal vulva, and the male has 20 to 23 contiguous ventromedian supplements. Egtitus sinensis n. sp. is 1.7-2.2 mm long; a = 24-33, b = 3.1-3.9, c = 16-19 in female and 0.7-0.9 in male; odontostyle length is 25-29 µm; spicules are 55-56 µm long; and the prerectum 53-77 µm long. The cardia is short and blunt conoid, 13-19 µm long. The male has 12 to 13 ventromedian supplements at intervals of 2-3 µm.     

Description and SEM Observations of a New Species of Cyst Nematode Heterodera goldeni (Nematoda: Heteroderidae) Attacking Panicum coloratum in Egypt

A cyst nematode, Heterodera goldeni n. sp., is photographed and described from Qasabagrass roots (Panicum coloratum L.) in Alexandria, Egypt. It is characterized in having second-stage juveniles with body length of 546 µm (450-612), stylet length of 22.6 µm (22-23.5) with anchor-shaped knobs, lateral field with 3 lines, tail 60-75 µm, hyaline tail terminus 38.4 µm (33-43); cysts are lemon-shaped, dark to light brown with an extensive sub-crystalline layer covering the entire cyst, cuticular midbody pattern zig-zag, cysts ambifenestrate, well-developed underbridge with finger-like projections, bullae present, vulva slit measuring 44-48 µm long. Males are absent, and females have heavy punctations on the cuticle. Its relationship to H. graminophila described from Florida and Louisiana and H. leuceilyma described from Florida are discussed. The present known distribution is restricted to Alexandria, Egypt. Its economic importance in rangeland grasses and cultivated crops such as rice is not known.     

Longidorus paravineacola n. sp. (Nematoda: Longidoridae), a New Species from Arkansas

Longidorus paravineacola n. sp., described herein, was found in a survey of longidorids of Arkansas. It is a parthenogeneticspecies characterized by its long body (6.68-9.85 mm); slightly expanded and rounded head, head width 21-27 µm; odontostyle length 95-114 µm; guide ring 28-37 µm posterior to the head end; short rounded tail, and c'' = 0.6-1.0. Longidorus paravineacola n. sp. is similar to the amphimictic species L. vineacola Sturhan &Weischer, 1964; L. balticus Brzeski, Peneva &Brown, 2000; L. kuiperi Brinkman, Loof &Barbez, 1987; and parthenogenetic species L. crassus Thorne, 1974, which also occurred in the type locality.     

Longidorus grandis n. sp. and L. paralongicaudatus n. sp. (Nematoda: Longidoridae), Two Parthenogenetic Species from Arkansas

Two new parthenogenetic species of Longidorus were found in Arkansas. Longidorus grandis n. sp. is characterized by its body (5.80-8.24 mm), slightly offset head, head width 20-27 µm, odontostyle 86-100 µm, guide ring 26-35 µm posterior to the anterior end, short conoid to mammiliform tail. Longidorus grandis n. sp. is similar to L. vineacola Sturhan &Weischer, 1964; L. lusitanicus Macara, 1985; L. edmundsi Hunt &Siddiqi, 1977; L. kuiperi Brinkman, Loof &Barbez, 1987; L. balticus Brzeski, Peneva &Brown, 2000; L. closelongatus Stoyanov, 1964; and L. seinhorsti Peneva, Loof &Brown, 1998. Longidorus paralongicaudatus n. sp. is characterized by its body length (2.60-5.00 µm), anteriorly flattened and offset head region 13-18 µm wide, odontostyle length 92-127 µm, guide ring 21-30 µm posterior to the anterior end, tail elongate-conical, and c'' = 1.2-2.6. Longidorus paralongicaudatus n. sp. most closely resembles L. longicaudatus Siddiqi, 1962; L. socialis Singh &Khan, 1996; L. juvenilis Dalmasso, 1969; and L. curvatus Khan, 1986.     

Hemicycliophora hellenica n. sp. (Nemata: Criconematidae) from Greece

Hemicycliophora hellenica n. sp. is described and illustrated from a bisexual population found in Filippias, Epirus, Greece, in the rhizosphere of giant reed (Arundo donax) and unidentified aquatic plants along the edge of irrigation canals. Hemicycliophora hellenica n. sp. is characterized by a long stylet (more than 120 µm), body length (L = 1,078-1,634 µm; R = 303-362), and lateral field marked by three lateral lines in females and four in males. The lip region is distinctive in that the female labial disc is oval and offset from the first lip region annule, and protrudes markedly; the male labial disc is very large, offset and rectangular, and protrudes distinctly. Hemicycliophora hellenica n. sp. resembles H. megalodiscus Loof by possession of a strongly protruding labial disc, but differs in having a longer female body, more body annules, longer stylet, and dorsally and ventrally indented head annules. The male labial plate is larger than in H. megalodiscus, and the male has four incisures in the lateral field vs. three in H. megalodiscus.     

Meloidogyne petuniae n. sp. (Nemata: Meloidogynidae), a Root-knot Nematode Parasitic on Petunia in Brazil

Meloidogyne petuniae n. sp. is described and illustrated from specimens parasitic on petunia (Petunia hybrida L.) in Brasilia, Brazil. The perineal pattern of the female is elongate to ovoid with a high, squarish arch and widely spaced, coarse striae. The stylet of the female is 12.9-16.5 µm long and has three small, rounded knobs that are distinctly set off from the shaft. Each knob is marked by a deep longitudinal indentation posteriorly and anteriorly. In SEM the base of the shaft appears to be divided into six distinct ridges. The excretory pore opens about 15.4-53.6 µm from the head end. Males are approximately 0.8-2.2 mm long. Most specimens have a high and narrow head cap, but in some the head cap is narrow and low. The stylet of the male is 21.1-26.0 µm long and has small, rounded knobs, set off from the shaft, but not indented as in the female. Second-stage juveniles are 353-464 µm long; the labial disc is fused with the medial lips to form a dumbbell-shaped head cap; the medial lips are indented posteriorly; and the head region is marked with one to two irregular annulations. The stylet is 9.2-10.8 µm long and has rounded, posteriorly sloping knobs. The tail is slender, approximately 46.4-57.2 µm long, and has a short hyaline terminus, 10.3-13.5 µm long. The somatic chromosome number is 2n = 41 and the esterase phenotype is VS1-S1, with S1 being a weak band. The malate dehydrogenase phenotype is N1, which is unique for this species. Petunia, tomato, tobacco, pea, and bean are good hosts; pepper, watermelon, and sweet corn are poor hosts; and peanut, cotton, and soybean are non-hosts. Galls produced by this species are smaller on petunia than on tomato.     

First Report of Korean Cyst Nematode,Heterodera koreana,Parasitic on Bamboo,Phyllostachys nigra,from Iran

Bamboo is grown sporadically in the north of Iran and is confined to very limited areas. The history of growing bamboo was to some extent simultaneous with the entrance, commencement, and growth of the tea industry in the north about a century ago. The bamboo was used for making baskets to transfer the harvested tea foliage from farm to the factory and other linked functions. A main area allocated for bamboo growing is located in Lahidjan Agricultural Research Station (LARS) in the north of Iran, where several species of bamboo were cultivated in an area of 5 ha. The species include five species of Phyllostachys (viz., P. aurea, P. bambusoides, P. decora, P. nigra, P. vivax) and one species of Arundinaria gigantean, Pleioblastus fortune, and Semiarundinaria fastuosa; however, only P. aurea and P. nigra have been precisely identified. A survey on plant parasitic nematodes associated with bamboo mainly on P. nigra in LARS revealed second-stage juveniles of cyst forming nematode in soil samples. Further analysis of root and soil samples led to recovery of a cyst nematode belonging to the genus Heterodera and the Afenestrata group. Cysts, vulval cone, and second-stage juveniles were studied for morphological and morphometric features. The classical identification was followed by amplification of the ribosomal RNA-ITS region and the D2-D3 expansion segments of 28S large-subunit rRNA gene; the amplified fragments were sequenced, edited, and compared with those of the corresponding published gene sequences. New D2-D3 and rRNA-ITS gene sequences were deposited in the GenBank database under the accession numbers {"type":"entrez-nucleotide","attrs":{"text":"KR818910","term_id":"924272655","term_text":"KR818910"}}KR818910 and {"type":"entrez-nucleotide","attrs":{"text":"KR818911","term_id":"924272662","term_text":"KR818911"}}KR818911, respectively. Based on the morphological and molecular data, the species of the cyst-forming nematode was identified as H. koreana (Vovlas et al., 1992; Mundo-Ocampo et al., 2008). The body contour of cysts was mainly subspherical, vey often with irregular shape (Fig. 1A), yellowish to light brown, thin cuticle with fine zigzag pattern, without fenestration, lacking bulla, and underbridge. Vulval lips protruded, cuticular pattern of vulval cone with a tuberculate area (Fig. 2B), and vagina embedded into vulval lips. The second-stage juveniles cylindrical and slender, hemispherical cephalic framework, with three lines in lateral field, well-developed rounded stylet knobs, tail conoid tapring to fine rounded terminus, phasmids posterior to anus. The cyst measurements were (n = 21) length 502 ± 70 (420 to 640) µm; width = 408 ± 60 (320 to 520) µm; length/width = 1.23 ± 0.09 (1.07 to 1.5) µm. The morphometric characters of vulval cone were measured (n = 7): fenestral length = 62.4 ± 6.5 (51 to 71) µm; fenestral width = 50.7 ± 3.2 (45 to 54) µm; vulval slit = 51.9 ± 4.3 (46 to 59) µm; distance from vulva to anus = 51.3 ± 4.4 (43 to 56) µm. Second-stage juveniles showed the following morphometric characters (n = 14): L = 455 ± 11.3 (437 to 472) µm; a = 29.9 ± 0.9 (28.3 to 31.5); b΄ = 2.7 ± 0.4 (2.2 to 3.5); c = 7.4 ± 0.9 (6 to 8.9); ć = 6.1 ± 0.4 (5.1 to 6.7); lip region height = 3 µm; lip region width = 7.5 ± 0.5 (7 to 8) µm; stylet length = 18.1 ± 0.5 (17 to 19) µm; anterior end to median bulb = 72.2 ± 1.7 (70 to 75) µm; anterior end to secretory-excretory pore = 99.7 ± 2.5 (96 to 103) µm; maximum body width = 15.2 ± 0.4 (15 to 16) µm; body width at anus = 10.1 ± 1 (8 to 11) µm; tail length = 62.0 ± 6.9 (51 to 74) µm; hyaline part of tail = 44.0 ± 1.8 (40 to 47) µm. The egg measurements for 11 individuals were length = 102.5 ± 7.9 (93 to 119) µm; width = 39.3 ± 4.2 (33 to 46) µm; length/width = 2.6 ± 0.3 (2.0 to 3.1). The morphology, morphometric characters and molecular data of the population of H. koreana isolated from bamboo in Iran are in agreement with those previously reported for this species (Vovlas et al., 1992; Mundo-Ocampo et al., 2008). At present, five species of Heterodera belonging to the Cyperi and Afenestrata groups were reported from bamboo, H. bamboosi (Kaushal and Swarup, 1988; Wouts and Baldwin, 1998) on Bambusa sp. from India; H. koreana on P. pubescence, P. aurea, and P. nigra from South Korea and the United States; and H. hainanensis (Zhuo et al., 2013), H. fengi (Wang et al., 2013), and H. guangdongensis (Zhuo et al., 2014) on P. pubescence from China; thus showing host suitability of bamboo for at least five species of cyst-forming nematodes. A greenhouse test performed by planting rice seed cv. Hashemi in soil containing H. koreana showed successful multiplication of Korean cyst nematode on rice seedlings after 2 mon. The exact date of the establishment of bamboo plantation in LARS is not precisely clear, but it indicates that the Korean cyst nematode was most likely brought with the imported bamboo seedlings from unknown origin several decades ago. According to our best knowledge, this is the first report of occurrence of H. koreana from Iran. So far the Korean cyst nematode was reported from South Korea, Thailand, and the United States, Florida (from nurseries); this study includes the distribution of this cyst-forming nematode in Iran and expands the information of the occurrence of H. koreana for the world.     

Longidorus biformis n. sp. and L. glycines n. sp. (Nematoda: Longidoridae): Two Amphimictic Species from Arkansas

Two new amphimictic species of Longidorus were found in Arkansas. Longidorus biformis n. sp., found in the rhizosphere of hardwood trees along streams in sandy soil in 14 Arkansas locations, is characterized by its long body (5.42-9.50 mm), wide expanded flattened head end, head width 20.0 to 26.0 µm, odontostyle 96 to 125 µm, guide ring 29 to 38 µm posterior to the anterior end, elongate conoid tail, and c'' = 0.9-2.1. Females with 2 to 11 vetromedian supplement-like structures were found in 2 of 14 populations of this new species. Longidorus biformis n. sp. is closest to L. seinhorsti Peneva, Loof &Brown, 1998 and L. closelongatus Stoyanov, 1964. Among North American species it is closest to L. glycines n. sp. A distinguishing feature of L. biformis n. sp. is the presence of supplement-like organs in some females. Longidorus glycines n. sp., found in soybean microplots at the Main Research Station, Fayetteville, Arkansas, is characterized by its long body (6.14-8.31 mm), wide offset flattened head end, head width 20.3 to 23.3 µm, odontostyle 87.3 to 99.5 µm, guide ring 22.3 to 26.4 µm posterior to the anterior end, short conoid tail with rounded terminus, and c'' = 0.9-1.4. Longidorus glycines n. sp. is closest to L. lusitanicus Macara, 1985. Among North American species it is close to L. biformis n. sp., L. breviannulatus Norton and Hoffman, 1975, and L. crassus Thorne, 1964. Both new species are believed to have four juvenile stages; the first stage was not found for L. biformis n. sp.     

Three new species of the genus Aporcelaimoides Heyns, 1965 from Vietnam (Nematoda,Dorylaimida, Aporcelaimidae), with an updated taxonomy of the genus

Three new species of Aporcelaimoides from natural habitats in Vietnam are studied, described and illustrated, including line drawings, LM and/or SEM pictures. Aporcelaimoides brevistylum sp. n. is characterized by its body 1.95–2.90 mm long, lip region offset by deep constriction and 17–18 µm broad, ventral side of mural odontostyle 11–14 µm long with aperture occupying 62–71% of its length, neck 663–767 µm long, pharyngeal expansion occupying 58–66% of total neck length, uterus a simple tube 85–182 µm long, pars refringens vaginae absent, V = 55–63, tail short and rounded (34–46 µm, c = 49–76, c’ = 0.6–0.8), spicules 67–86 µm long, and one ventromedian supplement out the range of spicules. Aporcelaimoides minor sp. n. is distinguished in having body 2.09–2.61 mm long, lip region offset by deep constriction and 19–20 µm broad, mural odontostyle 14–16 µm long at its ventral side with aperture occupying 73–84% of its length, neck 579–649 µm long, pharyngeal expansion occupying 57–66% of total neck length, uterus a simple tube 44–69 µm long, pars refringens vaginae well developed, V = 48–56, female tail very short, rounded conoid or truncate (14–26 µm, c = 90–146, c’ = 0.3–0.6), and male unknown. Aporcelaimoides silvaticum sp. n. is characterized by its body 2.09–2.60 mm long, lip region offset by depression and 17–18 µm broad, mural odontostyle 11–12 µm long at its ventral side with aperture occupying 60–66% of its length, neck 597–720 µm long, pharyngeal expansion occupying 58–64% of total neck length, uterus a simple tube 128–243 µm long, pars refringens vaginae well developed, V = 58–60, tail short and rounded (27–37 µm, c = 67–94, c’ = 0.6–0.7), spicules 64–75 µm long, and two or three widely spaced ventromedian supplements bearing hiatus. The genus Aporcelaimoides is restored, its diagnosis emended, and three species of Sectonema, namely Sectonema amazonicum, Sectonema haguei and Sectonema moderatum, transferred to it. An updated list of its species, a key to their identification and a tabular compendium with the most important morphometric features are also presented.     

Steinernema diaprepesi n. sp. (Rhabditida: Steinernematidae), a Parasite of the Citrus Root Weevil Diaprepes abbreviatus (L) (Coleoptera: Curculionidae)

A nematode collected from Diaprepes abbreviatus is identified and described as a new species, Steinernema diaprepesi n. sp. The new species is closely related to S. feltiae, S. glaseri, and S. oregonense and can be distinguished from these species by the following characteristics: Males: Spicule averaging 79 (71-90) µm and spicule shape; D% (distance from anterior end to excretory pore/ esophagus length × 100) about 80; the ratio SW (spicule length/anal body width) about 1.8. Females: Vulva with short, double- flapped epiptygma; tail terminus usually with 5 papillae-like structures. Infective juveniles: Body averaging 1,002 (880-1,133) µm, EP (distance from anterior end to excretory pore) = 74 (66-83) µm; tail length = 83 (65-91) µm, and E% (EP/tail length × 100) = 89.6 (78-114). Lateral field pattern variable, the formula for the arrangement of ridges from head to tail is: 2, 6, 7, 8, 4, 2. The portion with eight ridges is the longest. This new species can be differentiated further from three closest species (S. feltiae, S. glaseri, and S. oregonense) by characteristic sequences of their ITS regions, including sequence lengths, ratios of similarity, composition, and differences in base characters in sequence alignment.     

First Report of Northern Root-Knot Nematode,Meloidogyne hapla,Parasitic on Oaks,Quercus brantii and Q. infectoria in Iran

Root-knot nematodes (RKN) are the most serious plant parasitic nematodes having a broad host range exceeding 2,000 plant species. Quercus brantii Lindl. and Q. infectoria Oliv are the most important woody species of Zagros forests in west of Iran where favors sub-Mediterranean climate. National Botanical Garden of Iran (NBGI) is scheduled to be the basic center for research and education of botany in Iran. This garden, located in west of Tehran, was established in 1968 with an area of about 150 ha at altitude of 1,320 m. The Zagros collection has about 3-ha area and it has been designed for showing a small pattern of natural Zagros forests in west of Iran. Brant’s oak (Q. brantii) and oak manna tree (Q. infectoria) are the main woody species in Zagros collection, which have been planted in 1989. A nematological survey on Zagros forest collection in NBGI revealed heavily infection of 24-yr-old Q. brantii and Q. infectoria to RKN, Meloidogyne hapla. The roots contained prominent galls along with egg sac on the surface of each gall. The galls were relatively small and in some parts of root several galls were conjugated, and all galls contained large transparent egg masses. The identification of M. hapla was confirmed by morphological and morphometric characters and amplification of D2-D3 expansion segments of 28S rRNA gene. The obtained sequences of large-subunit rRNA gene from M. hapla was submitted to the GenBank database under the accession number {"type":"entrez-nucleotide","attrs":{"text":"KP319025","term_id":"852381377","term_text":"KP319025"}}KP319025. The sequence was compared with those of M. hapla deposited in GenBank using the BLAST homology search program and showed 99% similarity with those {"type":"entrez-nucleotide","attrs":{"text":"KJ755183","term_id":"667714404","term_text":"KJ755183"}}KJ755183, {"type":"entrez-nucleotide","attrs":{"text":"GQ130139","term_id":"239819330","term_text":"GQ130139"}}GQ130139, {"type":"entrez-nucleotide","attrs":{"text":"DQ328685","term_id":"84794916","term_text":"DQ328685"}}DQ328685, and {"type":"entrez-nucleotide","attrs":{"text":"KJ645428","term_id":"657709843","term_text":"KJ645428"}}KJ645428. The second stage juveniles of M. hapla isolated from Brant’s oak (Q. Brantii) showed the following morphometric characters: (n = 12), L = 394 ± 39.3 (348 to 450) µm; a = 30.9 ± 4 (24.4 to 37.6); b = 4.6 ± 0.44 (4 to 5.1); b΄ = 3.3 ± 0.3 (2.7 to 3.7), c = 8.0 ± 1 (6.2 to 10.3), ć = 5.3 ± 0.8 (3.5 to 6.3); Stylet = 12.1 ± 0.8 (11 to 13) µm; Tail = 50 ± 5.6 (42 to 57) µm; Hyaline 15 ± 1.8 (12 to 18) µm. Oak manna, Q. infectoria population of second stage juveniles clearly possessed short body length and consequently other morphometric features were less than those determined for Q. brantii population, and these features were: (n = 12), L = 359.0 ± 17.3 (319 to 372) µm; a = 28.6 ± 3 (22.8 to 31); b = 5.0 ± 0.3 (4.8 to 5.2); b΄ = 3.3 ± 0.2 (3 to 3.6), c = 8.1 ± 0.5 (7.4 to 8.8), ć = 4.7 ± 0.5 (3.9 to 5.2); Stylet = 11.4 ± 0.7 (10 to 12) µm; Tail = 44 ± 1.8 (42 to 47) µm; Hyaline 12 ± 1.7 (10 to 15) µm. To date two species of Meloidogyne, M. querciana Golden, 1979 and M. christiei Golden and Kaplan, 1986 have been reported to parasitize oaks (Quercus spp.) from the United States of America. M. querciana was found on pin oak Quercus palustris in Virginia. The oak RKN infected pine oak, red oak, and American chestnut heavily in greenhouse tests (Golden, 1979). The other species M. christiei was described from turkey oak and Q. laevis in Florida, which has monospecific host range (Golden and Kaplan, 1986). Both of these RKN species seem to be restricted to the United States of America and have not been reported from other place. According to our knowledge this is the first report of occurrence of M. hapla on Q. brantii and Q. infectoria in the world. This study includes these two oak species to the host range of RKN, M. hapla for the world and expands the information of RKN, M. hapla host ranges on oaks.     

Influence of spatial distribution and size of clones on the realized outcrossing rate of the marsh cinquefoil (Comarum palustre)

Background and Aims

Clonal growth is a common feature in flowering plants. As clone size increases, the selfing rate in self-compatible species is likely to increase due to more frequent geitono-pollination events (i.e. pollination among flowers within the same genet). This study investigated the breeding system of the marsh cinquefoil (Comarum palustre) and assessed spatial distribution of clones, clone size and architecture, and their effects on realized outcrossing rates. In addition, pollen dispersal was investigated in two patchy populations.

Methods

The species'' breeding system was investigated under controlled conditions through hand pollinations (self- vs. cross-pollination). Using microsatellite markers, an assessment was made of the realized outcrossing rates and the genetic diversity in four natural populations, the clonal structure in two populations within five 15 × 15 m sampling plots following 0·5 × 0·5 m grids, and the pollen dispersal through paternity assignment tests in those two populations.

Key Results Comarum palustre

is a self-compatible species but only presents a low rate of spontaneous self-pollination. The occurrence of inbreeding depression was not detected at the seed set stage (δ_SS = 0·04). Clones were spatially clumped (A_C = 0·60–0·80), with intermediate to no intermingling of the ramets (D_C = 0·40–1·00). Genet size ranged from one to 171 ramets. Patchy populations had low outcrossing rates (t_m = 0·33–0·46). Large clones showed lower outcrossing rates than small clones. Pollen dispersal mainly occurred within patches as only 1–7 % of the pollination events occurred between patches of >25 m separation. Seedling recruitment events were detected.

Conclusions

Genet size together with distances between patches, through increasing geitono-pollination events, appeared to be important factors influencing realized outcrossing rates. The study also revealed seed flow allowing seedling recruitment, which may contribute to increasing the number of new patches, and potentially further enhance gene flow within populations.     

Description of Non-Type Seinura winchesi from Mushroom Compost (Nematoda: Seinuridae)

Non-type material identified as Seinura winchesi, and deposited in the collection of the Nematology Department, Rothamsted Experimental Station, England, is described. The material was collected from mushroom compost in Leeds, England, in 1957. Females of this population are characterized by a set-off head, knobless stylet (20-21 µm), two rows of oogonia-oocytes, and absence of a postuterine sac. The median bulb is oblong and, at times, is constricted in the middle. The body is 565 to 675 µm long and tapers posteriorly to a pointed terminus. The cuticle is finely annulated, and there are three incisures in the lateral field. The ovary is outstretched and overlaps the esophageal gland lobes. A spermatheca is present, and spermatozoa are visible. The vulva is posteriorly located (V = 77-80), and a flap is absent. Males are 550 to 680 µm long with a spicate tail that bears three pairs of subventral papillae. The spike is short (14-18 µm), about one-half the tail length. The testis is 360 to 412 µm long, not reflexed, and at times overlaps the esophageal gland lobes. Spermatogonia-spermatocytes are in two rows. Spicules are 14 to 15 µm long with a prominent apex, and small rostrum. A bursa and gubernaculum are absent.     

Morphological and Molecular Characterization of Gracilacus wuae n. sp. (Nematoda: Criconematoidea) Associated with Cow Parsnip (Heracleum maximum) in Ontario,Canada

Gracilacus wuae n. sp. from soil associated with cow parsnip in Ontario, Canada is described and illustrated. Morphologically, females have a long stylet ranging from 80 to 93 µm long, the lip region not offset from the body contour, without lateral lips but with large and flat submedian lobes, the mouth opening slit-like elongated laterally and surrounded by lateral flaps, the excretory pore is anterior to the knobs of the stylet; males without stylet and the pharynx degenerated. The fourth-stage juveniles lack a stylet, the pharynx degenerated, and can be differentiated into preadult females and males based on the position of the genital primordia. The third-stage juveniles are similar to females but smaller. Phylogenetic studies using the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer (ITS) sequences collectively provide evidence of a grouping with other Gracilacus and some species of Paratylenchus with stylet length of females longer than 41 µm deposited in GenBank.     

Descriptions of Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina) from Haryana,India

Two different nematodes were isolated from the bark of Albizia lebbeck trees; one from insect infested and another from noninfested, healthy tree. Based on the biological, morphological, and molecular evidences, the nematodes are described as Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina). Deladenus albizicus n. sp., isolated from insect-infested tree, multiplied on the fungus Nigrospora oryzae. Myceliophagous females of this nematode reproduced by parthenogenesis and spermathecae were indistinct. Infective females, readily produced in the cultures, are dorsally curved. Only one type of males containing small-sized sperms in their genital tracts were produced in the culture. Myceliophagous females: L = 0.75 to 1.71 mm, a = 32.3 to 50.8, b = 9.3 to 11.2, b’ = 5.2 to 7.3, c = 27.2 to 35.6, V = 91.0 to 93.3, c’ = 2.0 to 2.9, stylet = 11 to 12 µm, excretory pore in the region of median pharyngeal bulb, 43 to 47 µm anterior to hemizonid. Deladenus processus n. sp., isolated from bark of healthy A. lebbeck tree, was cultured on Alternaria alternata. Myceliophagous females reproduced by amphimixis and their spermathecae contained rounded sperms. Infective females were never produced, even in old cultures. Myceliophagous females: L = 0.76 to 0.99 mm, a = 34 to 49, b = 13.3 to 17.7, b’ = 3.8 to 5.8, c = 19.6 to 22.8, V = 92.2 to 93.5, c’ = 2.7 to 3.5, stylet = 6 to 7 µm, excretory pore in the proximity of hemizonid, tail conoid, tapering from both sides to a long pointed central process. It is proposed to classify Deladenus species in three groups: durus, siricidicola, and laricis groups based on female and spermatogonia dimorphism, mode of reproduction, and insect parasitism.     

Myxobolus myleus n. sp. infecting the bile of the Amazonian freshwater fish Myleus rubripinnis (Teleostei: Serrasalmidae): morphology and pathology

Myxobolus myleus n. sp. is described from the gall-bladder of the freshwater fish Myleus rubripinnis collected near the city of Oriximiná in the Amazon System, Brazil. The spores obtained from the bile contained two equal symmetrical and smooth valves, each forming the spore wall. The spores were large, with a cone-like form, a semi spherical basal contour and measured (in μm) 19.3 ± 0.5 (n = 25) × 8.3 ± 0.5 (n = 25) × 4.0 ± 0.3 (n = 15). The apical end of the spores contained two elongate, equal and pointed conical polar capsules measuring 13.2 ± 0.4 μm (n = 25) in length and 3.0 ± 0.3 μm (n = 15) in width, each having a slightly tapering polar filament with 19 to 21 turns. The polar capsules were extended below at about 4/5 of the total length of the spores. The sporoplasm was binucleate and contained some sporoplasmosomes. All infected fish presented hypertrophy of the gall-bladder due to presence of the brownish parasite floating in the bile. In this paper we describe this new species of myxosporean based on light and ultrastructural observations, together with its associated pathology.     

A revision of the new world species of Polytrichophora Cresson and Facitrichophora,new genus (Diptera,?Ephydridae)

The New World species of Polytrichophora Cresson and Facitrichophora new genus, are revised. Fifteen new species are described (type locality in parenthesis): Facitrichophora atrella sp. n. (Costa Rica. Guanacaste: Murciélago [10°56.9''N, 85°42.5''W; sandy mud flats around mangrove inlet]), Facitrichophora carvalhorum sp. n. (Brazil. São Paulo: Praia Puruba [23°21''S, 44°55.6''W; beach]), Facitrichophora manza sp. n. (Trinidad and Tobago. Trinidad. St. Andrew: Lower Manzanilla (12 km S; 10°24.5''N, 61°01.5''W), bridge over Nariva River), Facitrichophora panama sp. n. (Panama. Darien: Garachine [8°04''N, 78°22''W]), Polytrichophora adarca sp. n. (Barbados. Christ Church: Graeme Hall Nature Sanctuary [13°04.2''N, 59°34.7''W; swamp]), Polytrichophora arnaudorum sp. n. (Mexico. Baja California. San Felipe [31°01.5''N, 114°50.4''W]), Polytrichophora barba sp. n. (Cuba. Sancti Spiritus: Topes de Collantes [21°54.4''N, 80°01.4''W, 670 m]), Polytrichophora flavella sp. n. (Peru. Madre de Dios: Rio Manu, Pakitza [11°56.6''S, 71°16.9''W; 250 m]), Polytrichophora marinoniorum sp. n. (Brazil. Paraná: Antonina [25°28.4''S, 48°40.9''W; mangal]), Polytrichophora rostra sp. n. (Peru. Madre de Dios: Rio Manu, Pakitza [11°56.6''S, 71°16.9''W; 250 m]), Polytrichophora sinuosa sp. n. (Trinidad and Tobago. Trinidad. St. Andrew: Lower Manzanilla [12 km S; 10°24''N, 61°02''W]), Polytrichophora mimbres sp. n. (United States. New Mexico. Grant: Mimbres River [New Mexico Highway 61 & Royal John Mine Road; 32°43.8''N, 107°52''W; 1665 m]), Polytrichophora salix sp. n. (United States. Alaska. Matanuska-Susitna: Willow Creek [61°46.1''N, 150°04.2''W; 50 m]), Polytrichophora sturtevantorum sp. n. (United States. Tennessee. Shelby: Meeman Shelby State Park [Mississippi River; 35°20.4''N, 90°2.1''W; 98 m]), Polytrichophora prolata sp. n. (Belize. Stann Creek: Cockscomb Basin Wildlife Sanctuary [16°45''N, 88°30''W]). All known New World species of both genera are described with an emphasis on structures of the male terminalia, which are fully illustrated. Detailed locality data and distribution maps for all species are provided. For perspective and to facilitate recognition, the tribe Discocerinini is diagnosed and a key to included genera is provided.