首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Abstract

Across 88 sites 9 species were found, with Anaplectus granulosus at 56 sites, Plectus parietinus at 47, P. longicaudatus at 30, P. parvus at 15, P. cirratus and Wilsonema otophorum at 11, P. armatus and A. porosus at 4, and Tylocephalus auriculatus at 1 site. A key to Anaplectus males is given. For nine sites mean length of female A. granulosus is negatively correlated with mean annual air temperature. The most diverse fauna comprised six species in Kaitoke silt loam; it appears that faunal diversity increases with higher rainfall. Species apparently coexist through separation in size and time. Tylocephalus was only found in soils with a thermic soil temperature regime.  相似文献   

2.
Abstract

Helicotylenchus species collected from managed soils in New Zealand were identified. They were found at 159 sites. H. pseudorobustus was found at 82 of these sites, H. labiatus at 56, H. varicaudatus at 28, and H. canadensis at 4. Only 11 sites had more than one species present and most (7) of these sites had mixtures of H. pseudorobustus and H. labiatus. H. labiatus, reported only twice before, was the most common species found in cotula bowling greens. H. canadensis was restricted to sites south of 45°S. Measurements are given for 15 populations, and H. labiatus is illustrated. Characters separating the four species are given.  相似文献   

3.
Abstract

Across 64 sites 8 species were found, with Clarkus propapillatus at 60 sites, C. composticola at 7, Prionchulus muscorum at 3, Mylonchulus ubis at 7, M. sigmaturus at 1, Cobbonchus australis at 9, lotonchus basidontus at 4, and I. stockdilli n. sp. at 3 sites. Sampling effort varied at the sites and significant annual and management effects have previously been reported on mononchid populations. No clear geographic or soil factor is apparent in the distributions, but more species may occur at sites with higher annual rainfall. lotonchus stockdilli n. sp. is a large (female L = 3.05–5.90 mm), bisexual species with dorsal tooth at the posterior of the sclerite, female tail about 400 μm or 14%, and no cuticular pores in the vulval region.  相似文献   

4.
5.
Abstract

Information on the “needle nematode” Longidorus elongatus in New Zealand pastures has hitherto been limited. Monthly sampling of Pukepuke black sand and Manawatu fine sandy loam yielded L. elongatus populations up to 87 500 m?2 (February) and 21 600 m?2 (August). First stage juveniles appeared when soil temperature exceeded 15°C; females dominated populations every month and males were rare. Differences in abundance between soils may reflect the pore space available to these relatively large nematodes. Specimens survived 24 weeks storage at 5 and 15°C. While abundance tended to decline with depth, at 30–40 cm depth in Pukepuke sand, numbers increased, perhaps through the impact of groundwater levels on rooting patterns. In Pukepuke sand, plant species were associated with significantly different populations of L. elongatus, with Trifolium repens and T. subter‐raneum supporting more than Lolium perenne. More L. elongatus were found in grazed pasture with lower plant available P.  相似文献   

6.
Pratylenchus penetrans did not reproduce without males. Cytological examination indicated that cross-fertilization occurred. Females had a chromosome number of 2n = 12. Virgin females reared in isolation laid eggs, but these failed to undergo cleavage. Males reared in isolation produced sperms.  相似文献   

7.
Summary The family Heteroderidae is revised. On the basis of shared, derived characters sister groups are established and arranged in a phylogenetic tree. A hypothetical, primitive ancestor for the family is defined. The genus Verutus has a large equatorial vulval slit and is considered to be the most primitive form. The genus Meloidodera developed by a reduction in vulval size. Genera which developed later exhibit a subterminally located vulval slit and progressively lost the annulation of the female cuticle. In this process four evolutionary lines emerge: (i) a posterior shift of the vulva and the formation of more or less distinct vulval lips gave rise to the genera Zelandodera and Cryphodera; (ii) changes in the lip configuration of the second-stage juvenile gave rise to the genera Hylonema, Afrodera n.g., Heterodera and Bidera; (iii) changes in the composition of the female cuticle resulted in the genera Thecavermiculatus, Atalodera, Sherodera, Sarisodera and Bellodera n.g. and; (iv) a reduction in vulval slit size led to the development of the genera Dolichodera, Globodera, Cactodera and Punctodera. The genera Ephippiodera and Rhizonema are synonymized with Bidera and Sarisodera respectively. Verutus and Meloidodera are recognized as subfamilies Verutinae and Meloidoderinae and the genera in the four evolutionary lines are recognized as subfamilies Cryphoderinae, Heteroderinae, Ataloderinae and Punctoderinae respectively.Two new genera, Afrodera and Bellodera, are erected for species originally described in Sarisodera and Cryphodera. Both new genera are characterized by a depressed vulval slit and the anus located on the dorsal side of the vulval cone. Differences in lip configuration of the infective juvenile and a postulated difference in female cuticle justifies their placement in different subfamilies. The lip configuration of the infective juveniles in the subfamilies Verutinae, Meloidoderinae, Cryphoderinae, Ataloderinae and Punctoderinae remains basically unchanged. The possible development of this character in the subfamily Heteroderinae is discussed and illustrated. The family Heteroderidae, its six subfamilies and 17 genera are defined or redefined, and for each of the genera the nominal species and their synonyms are listed. New synonyms introduced are: Heterodera rumicis and H. scleranthi of H. trifolii, H. ustinova of Bidera avenae and H. mali of Globodera chaubattia. Cactodera acnidae (Schuster & Brezina, 1979) n. comb. and Dolichodera andinus (Golden, Franco, Jatala & Astogaza, 1983) n. comb. are transferred from Heterodera and Thecavermiculatus respectively. Keys are provided for all taxa for which no suitable keys are available in the literature. Species inquirendae are listed. ac]19840606  相似文献   

8.
A new genus (Cerchnotocriconenta) and three new species (C. psephinum, Hemicycliophora amchitkaensis, and Paratylenchns amundseni) are described from Adak and Amchitka Islands in the Aleutian chain. The new genus differs from all other criconematid genera in having irregular, convex sculpturing consisting of small, oval plates on the anterior and posterior regions of each annule, with the mid-annular region minutely punctate or dentate. H. arnchitkaensis n. sp. resembles H. similis Thorne and H. zuckermani Brzeski, but has only one head annule, instead of two. P. antundseni n. sp., which has a stylet 17-19 μm long, is similar to P. tateae Wu &Townshend and P. labiosus Anderson &Kimpinski, but differs by the presence of males and the possession of conoid-truncate lip region, functional spermatheca, and long male tail (c = 8.5-9.5). Seriespinula seymouri Wu (Mehta &Raski), Nothocrieonema longulum (Gunhold) De Grisse &Loof, and Macroposthonia xenoplax (Raski) De Grisse &Loof are also reported from the islands.  相似文献   

9.
Development of Tylenchorhynchus claytoni from unsegmented egg to hatching takes 135 hr at 22-25 C. The fourth molt lasts 5 to 6 days. During exsheathment the cast cuticle of the larva separated into two unequal parts, breaking near either the anterior or posterior end. The life cycle from egg to egg required from 31 to 38 days at 28 C on alfalfa seedlings and included four molts and four larval stages. Sexual differentiation was apparent in third-stage larvae.  相似文献   

10.
Summary The taxonomy of those Tylenchorynchinae which have longitudinal lines or ridges on the cuticle is discussed. Dolichorhynchus is restricted to species with four incisures in the lateral field, lateral vulval flaps and a terminally notched bursa. D. prophasmis n. sp. is described. Neodolichorhynchus n. g. is erected for those species previously in Dolichorhynchus which have no lateral vulval flaps and a normal bursa, including: N. microphasmis (Loof, 1959) n.comb., N. judithae (Andrássy, 1962) n.comb., N. sulcatus (de Guiran, 1967) n.comb., and N. gladiolatus (Fortuner & Amougou, 1973) n.comb. Tessellus n.g. is proposed for T. claytoni (Steiner, 1937) n.comb. and T. pachys (Thorne & Malek, 1968) n.comb. the only remaining Tylenchorhynchus species with longitudinal cuticular lines. They are characterized by a rounded non-offset lip region, four incisures in the lateral field and a cuticular annulation divided into prominent blocks by deep longitudinal cuticular lines.  相似文献   

11.
Thirty populations of Meloidogyne of diverse geographic origin representing 10 nominal species and various reproductive, cytological, and physiological forms known to exist in the genus were examined to determine their enzymatic relationships. The 184 bands resolved in the study of 27 enzymes were considered as independent characters. Pair-wise comparisons of populations were performed in all possible combinations to estimate the enzymatic distances (ED) and coefficients of similarity (S). A phylogenetic tree was constructed. The apomictic species M. arenaria, M. microcephala, M. javanica, and M. incognita shared a common lineage. M. arenaria was highly polytypic, whereas conspecific populations of M. javanica and M. incognita were largely monomorphic. The mitotic and meiotic forms of M. hapla were very similar (S = 0.93), suggesting that the apomictic race B evolved only recently from the meiotic race A. The five remaining meiotic species (M. chitwoodi, M. graminicola, M. graminis, M. microtyla, and M. naasi - each represented by a single population) were not closely related to each other or to the mitotic species.  相似文献   

12.
13.
Summary Tylenchorhynchus microconus n.sp. from around roots of Australian acacia in West Bengal, India has females 0.46–0.65 mm long with coarse body annules, 15–18 m long spear with conus less than half its total length and a short conoid tail (c >1.7–2.8) with 10–15 annules and smooth terminus. T. crassicaudatus leviterminalis n.subsp. differs from T. c. crassicaudatus Williams, 1960 in having a small smooth lip region lacking annules. T. coffeae Siddiqi & Basir, 1959 is fully described from type specimens. ac]19811221  相似文献   

14.
A stunt nematode, Tylenchorhynchus thermophilus n. sp., is described and illustrated from soil collected around roots of saltgrass (Distichlis spicata) in Death Valley, California. It is distinguished from the similar species, T. ewingi, T. mexicanus, and T. mashoodi, in having a longer female body, longer tail with more annules, and larger phasmids. Physical and chemical analysis of soil from saltgrass roots showed it to consist of 71% sand and possess high salinity (salt content of 0.51%) and a pH of 9.3.  相似文献   

15.
16.
Perry R. N., Wharton D. A. and Clarke A. J. 1982. The structure of the egg-shell of Globodera rostochiensis (Nematoda: Tyienchida). International Journal for Parasitology12: 481–485. The ultrastructure and histochemistry of the egg-shell of Globodera rostochiensis are described. The eggshell consists of an outer vitelline layer, a chitinous layer and an inner lipid layer. The vitelline layer is not unit membrane-like and has strands of particulate material attached to its outer surface. The chitinous layer is made up of fibres consisting of a chitin microfibril core, surrounded by a protein coat. The lipid layer contains lipoprotein membranes. These vary in number, the most commonly observed pattern being two or three membranes loosely associated with the inner surface of the egg-shell.  相似文献   

17.
Two new species of plant parasitic nematodes (Tylenchorhynchus quaidi n. sp. and T. tritici n. sp.) from Pakistan are described and illustrated. Tylenchorhynchus quaidi n. sp., from soil around roots of potato (Solanum tuberosum) from an experimental field of NNRC, Karachi, Pakistan, is distinguishable from other species by its peculiar sunken dome-shaped head. Although similar to T. goffarti, it differs by head shape, areolation of lateral field, ratios a (23-28 vs. 29-37) and c (11-14 vs. 13-20), and a vagina that is half sclerotized and half unsclerotized. Tylenchorhynchus tritici n. sp., from soil around roots of wheat (Triticum aestivum) from Campbellpur, Pakistan, is similar to T. ventrosignatus and T. nordiensis. It differs from T. ventrosignatus by a continuous lip region, number of head annules (2-3 vs. 4), coarse body annulation, absence of a wave-like structure near the vulva, and by tail shape and number of tail annules (15-23 vs. 28-32). It differs from T. nordiensis by stylet length (12.4-14.6 vs. 11-13 μm), shape of stylet knobs, number of head annules (2-3 vs. 4), non-areolated lateral field in region of phasmids, and not fusing in posterior third of tail. Morphometrics of Tylenchorhynchus claytoni from soil around stunted maize (Zea mays L.), in Muscatine County, Iowa, and several other populations are given. Detailed morphometric data on T. claytoni based on topotypes collected from type locality and several other populations revealed that this species shows variations in the shape of tail in females, number of tail annules (and sometimes annules extending further back on the terminus, almost being an annulated terminus), position of phasmid, and shape of lip region. The subgenus Bitylenchus is proposed as a new synonym of Tylenchorhynchus and its species referred to the latter genus.  相似文献   

18.
In tropical forests, much of the plant diversity is due to a large number of congeneric taxa. It is unclear what ecological processes are responsible for the number and composition of co‐occurring species in these forests. Here, we present strong evidence that microhabitat heterogeneity may contribute to the coexistence of many different Inga species in just 100 ha. We examined their patterns of abundance and diversity in 75 transects related to the edaphic variables: soil water content, pH and soil texture at three different microtopographical units (ridges, slopes and valleys). We used two different approaches: Inga community level analyses and individual‐species analyses. Multivariate analyses, controlled for spatial autocorrelation, demonstrated that species show a distributional gradient mainly related to soil water content and to a lesser degree pH. Individual‐species analyses determined that obligate microhabitat restriction is uncommon: only 2 of 37 species analyzed were restricted to a single microhabitat. Habitat association analyses, however, identified a number of species characteristic of the ridge, slope and valley microhabitats. We conclude that the environmental setting plays an important role in the Inga community assembly but is not sufficient to explain the coexistence of 37 sympatric species at a single site.  相似文献   

19.
20.
Dolichodorus miradvulvus n. sp. from Anubias nana Engler in Florida is described and illustrated. The female is characterized by deep grooves in the cuticle on the ventral surface just anterior and posterior to the vulva, and by transversely elongate pouches anterior and posterior to the vulva. Both sexes have a constricted area of the stylet shaft just anterior to the knobs, and on the male the intersection of the lateral field and bursa appear sclerotized.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号