Intensive management facilitates bacterial invasion on soil microbial community.

Intensive management has greatly altered natural forests, especially forests around the world are increasingly being converted into economic plantations. Soil microbiota are critical for community functions in all ecosystems, but the effects of microbial disturbance during economic plantation remain unclear. Here, we used Escherichia coli O157:H7, a model pathogenic species for bacterial invasion, to assess the invasion impacts on the soil microbial community under intensive management. The E. coli invasion was tracked for 135 days to explore the instant and legacy impacts on the resident community. Our results showed that bamboo economic plantations altered soil abiotic and biotic properties, especially increasing pH and community diversity. Higher pH in bamboo soils resulted in longer pathogen survivals than in natural hardwood soils, indicating that pathogen suppression during intensive management should arouse our attention. A longer invasion legacy effect on the resident community (P < 0.05) were found in bamboo soils underlines the need to quantify the soil resilience even when the invasion was unsuccessful. Deterministic processes drove community assembly in bamboo plantations, and this selection acted more strongly during by E. coli invasion than in hardwood soils. We also showed more associated co-occurrence patterns in bamboo plantations, suggesting more complex potential interactions within the microbial community. Apart from community structure, community functions are also strongly related to the resident species associated with invaders. These findings provide new perspectives to understand intensive management facilitates the bacterial invasion, and the impacts would leave potential risks on environmental and human health.

New Distribution and Molecular Diversity of the Reniform Nematode Rotylenchulus macrosoma (Nematoda: Rotylenchulinae) in Europe.

Reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant species roots and occur largely in regions with temperate, subtropical, and tropical climates. In this study, we provide new records of the nematode Rotylenchulus macrosoma in eight European countries (Czech Republic, France, Germany, Hungary, Italy, Romania, Serbia, and Portugal), in addition to the six Mediterranean countries (Greece, Israel, Jordan, Spain, Syria, and Turkey) where the nematode was previously reported. Four new host species (corn, pea, wheat, and an almond-peach hybrid rootstock) are added to the recorded host species (bean, chickpea, hazelnut, peanut, soybean, and wild and cultivated olive). Molecular analyses based on the cytochrome c oxidase subunit coxI and D2-D3 segments of 28S RNA markers showed high diversity and pronounced genetic structure among populations of Rotylenchulus macrosoma. However, the complexity of phylogeographic patterns in plant-parasitic nematodes may be related to the intrinsic heterogeneity in the distribution of soil organisms, a rare occurrence of a species, or the potential human impact associated with agricultural practices.

A new rare nematode Nothocriconemoides hangzhouensis n. sp. (Nematoda: Criconematidae) from Hangzhou, China.

The Family Criconematidae is commonly referred as ring nematodes that include some members with economic importance as plant parasites. During a recent nematode inventory survey at Zhejiang Province, China, a new species of genus Nothocriconemoides was detected in the rhizosphere of elm tree. Nothocriconemoides hangzhouensis n. sp. can be characterized by the female body having annuli with fine longitudinal striations and 2 to 3 anastomoses at the posterior half of the body. The first cephalic annulus is rounded and expanded enclosing the lip region, and the second annulus is narrow, offset, collar like. En face view shows a central elevated labial disk bearing four distinct equal-sized submedian lobes and "I" shaped oral aperture. Excretory pore is located 3-4 annuli posterior to esophageal bulb. Vagina is straight and vulva closed. The ventral side of postvulval annuli is inverted, in majority of individuals. Anus is indistinct and located on the next annuli posterior to vulva. Tail is short, conoid, with forked or branched terminus. Juveniles are devoid of collar-shaped annuli in the lip region. The cephalic region has two rounded annuli where the first annulus shows slight depression in the middle. Body annuli are finely crenated. Anus is indistinct and located 3 to 4 annuli from tail terminus. Tail is short ending in a single lobed terminus. Phylogenetic studies based on analysis of the D2-D3 expansion segments of the 28 S rRNA, ITS rRNA, partial 18 S rRNA, and coxI gene revealed that the new species formed a separate clade from other criconematid species, thereby supporting its status as a new species of the genus. The new species showed close relationships with Discocriconemella sinensis. Additionally, this is the first record of genus Nothocriconemoides from China.The Family Criconematidae is commonly referred as ring nematodes that include some members with economic importance as plant parasites. During a recent nematode inventory survey at Zhejiang Province, China, a new species of genus Nothocriconemoides was detected in the rhizosphere of elm tree. Nothocriconemoides hangzhouensis n. sp. can be characterized by the female body having annuli with fine longitudinal striations and 2 to 3 anastomoses at the posterior half of the body. The first cephalic annulus is rounded and expanded enclosing the lip region, and the second annulus is narrow, offset, collar like. En face view shows a central elevated labial disk bearing four distinct equal-sized submedian lobes and "I" shaped oral aperture. Excretory pore is located 3­4 annuli posterior to esophageal bulb. Vagina is straight and vulva closed. The ventral side of postvulval annuli is inverted, in majority of individuals. Anus is indistinct and located on the next annuli posterior to vulva. Tail is short, conoid, with forked or branched terminus. Juveniles are devoid of collar-shaped annuli in the lip region. The cephalic region has two rounded annuli where the first annulus shows slight depression in the middle. Body annuli are finely crenated. Anus is indistinct and located 3 to 4 annuli from tail terminus. Tail is short ending in a single lobed terminus. Phylogenetic studies based on analysis of the D2­D3 expansion segments of the 28 S rRNA, ITS rRNA, partial 18 S rRNA, and coxI gene revealed that the new species formed a separate clade from other criconematid species, thereby supporting its status as a new species of the genus. The new species showed close relationships with Discocriconemella sinensis. Additionally, this is the first record of genus Nothocriconemoides from China.

Integrative taxonomy of Xiphinema histriae and Xiphinema lapidosum from Spain.

Three populations of Xiphinema non-americanum group species were detected in agricultural and natural ecosystems, during routine surveys for plant-parasitic nematodes in Spain. Based on morphological and molecular analyses, the species were identified as Xiphinema histriae and Xiphinema lapidosum, being this the first record and molecular characterization of both species in Spain. The morphometrics and morphology of the Spanish populations agree with those of the original description and paratype specimens and the present study provided a first description of the second to fourth juvenile stages of both species. A detailed study on the morphology in the Spanish populations of X. histriae, as well as in paratypes, showed a pseudo-Z-organ with weakly muscularized wall and containing numerous small dense granular bodies, which was different to the original description by Lamberti et al. (1993). This new finding suggests that X. histriae must be considered a member of the morphospecies Group 5 of X. non-americanum. Phylogenetic analysis based on D2 to D3 expansion segments of 28S gene, ITS1 and partial CoxI gene indicated that X. histriae and X. lapidosum are phylogenetically related with other Xiphinema non-americanum group spp. reported from Spain. Considering the pathological and economic importance of this group of nematodes, the combination of morphological characters, measurements, and molecular analysis is crucial for accurate identification of these species.

Morphological and Molecular Characterization of Paralongidorus sali Siddiqi, Hooper, and Khan, 1963 with a Description of the First-Stage Juvenile and Male of Longidorus jonesi Siddiqi, 1962 from China.

Longidorids are economically important plant-parasitic nematodes because several species are virus vectors. Populations of Paralongidorus sali and Longidorus jonesi , isolated from woody perennials of Hangzhou, Zhejiang, China, were characterized molecularly and morphologically. The morphometric data of the Chinese populations of both species were compared with other populations. The present study provided a first record of the occurrence of Paralongidorus in China coupled with description of the first-stage Juvenile and male of L. jonesi . Phylogenetic analysis based on 18S and D2-D3 expansion segments of 28S gene indicated that L. jonesi clustered with L. jonesi reported from Japan and P. sali grouped with P. bikanerensis from Iran. Considering the pathological and economic importance of this group of nematodes, the study emphasized the need of updated descriptions from accurately identified specimens, isolation of sufficient material for examination, and molecular and phylogenetic analysis for a better understanding and diagnostics of Longidorid nematodes.

Description of Gracilacus paralatescens n. sp. (Nematoda:Paratylenchinae) found from the rhizosphere of Bamboo in Zhejiang, China.

Gracilacus paralatescens n. sp., isolated in Anji County, Zhejiang Province, China from the rhizospheric soil of bamboo. The new species can be characterized by the female lateral field with three incisures, stylet 71.5 to 78.8 µm long, lip region truncated, excretory pore located anterior to basal knobs. Vulval lips non-protruding and without vulval flap, spermatheca large, elongated squarish shaped filled with sperms. Tail slender, relatively straight having wedge shape terminus. The spicule slender, slightly curved and 17.5 to 18.9 µm long. In the phylogenetic analysis based on 18S, D2-D3 of 28S and ITS regions of rDNA, the new species is clustered with Paratylenchid species having longer stylet length. Morphologically, the new species belongs to Group 9 of Paratylenchus sensu lato and is most similar to G. latescens.Gracilacus paralatescens n. sp., isolated in Anji County, Zhejiang Province, China from the rhizospheric soil of bamboo. The new species can be characterized by the female lateral field with three incisures, stylet 71.5 to 78.8 µm long, lip region truncated, excretory pore located anterior to basal knobs. Vulval lips non-protruding and without vulval flap, spermatheca large, elongated squarish shaped filled with sperms. Tail slender, relatively straight having wedge shape terminus. The spicule slender, slightly curved and 17.5 to 18.9 µm long. In the phylogenetic analysis based on 18S, D2-D3 of 28S and ITS regions of rDNA, the new species is clustered with Paratylenchid species having longer stylet length. Morphologically, the new species belongs to Group 9 of Paratylenchus sensu lato and is most similar to G. latescens.

Irradiation-Assisted Enhancement of Foaming and Thermal Gelation Functionality of Liquid Egg White.

Ionizing radiation has its unique popularity as a non-thermal decontamination technique treating with protein-rich foodstuffs to ensure the microbial and sensory quality, particularly for shell eggs. However, the changes in the functional properties of egg protein fractions such as liquid egg white (LEW) with macro/microstructural information are still controversial. Hence, this study was designed to elaborate the foaming and heat-set gelation functionality of LEW following different γ-ray irradiation dose treatments (0, 1, 3 or 5 kGy). For such, the physicochemical properties (active sulfhydryl and the hydrophobicity of protein moieties), structural characteristics (through X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry) and interfacial activities (rheological viscosity, interfacial tension, microrheological performance) were investigated. Then, the thermal gelation of LEW in relation to the texture profile and microstructure (by means of a scanning electron microscope) was evaluated followed by the swelling potency analysis of LEW gel in enzyme-free simulated gastric juice. The results indicated that irradiation significantly increased the hydrophobicity of liquid egg white proteins (LEWPs) (p < 0.05) by exposing non-polar groups and the interfacial rearrangement from a ß-sheet to linear and smaller crystal structure, leading to an enhanced foaming capacity. Microstructural analysis revealed that the higher dose irradiation (up to 5 kGy) could promote the proteins' oxidation of LEW alongside protein aggregates formed in the amorphous region, which favored heat-set gelation. As evidenced in microrheology, ≤3 kGy irradiation provided an improved viscoelastic interface film of LEW during gelatinization. Particularly, the LEW gel treated with 1 kGy irradiation had evident swelling resistance during the times of acidification at pH 1.2. These results gave new insight into the irradiation-assisted enhancement of foaming and heat-set gelation properties of LEW.

Distribution of trichodorid species in mainland China with description of Trichodorus hangzhouensis sp. nov. (Nematoda, Triplonchida).

Seven trichodorid species including a new one (Trichodorus hangzhouensis sp. nov., T. nanjingensis, T. pakistanensis, T. cedarus, Paratrichodorus porosus, Nanidorus renifer and N. minor) were recovered from the rhizosphere of different hosts in 13 provinces of China. Each of the recovered species was characterized based on morphology and molecular data using rRNA gene sequences. Trichodorus hangzhouensis sp. nov. is characterized by its males having medium-sized onchiostyle (46-49 µm) and three ventromedian cervical papillae (CP) anterior to the secretory-excretory (S-E) pore, CP1 located opposite the anterior part of isthmus, S-E pore opposite the isthmus or anterior end of pharyngeal bulb, spicules slightly ventrally curved, relatively small, 33.2 (32.0-34.5) µm long, wider slightly marked capitulum, lamina partially striated without bristles at striation; and females having rounded triangular sclerotized vaginal pieces with tips directed towards vulva, 1.5-2.0 µm sized, at about 1 µm apart, vulva pore-like in ventral view. Phylogenetic analysis based on D2-D3 28S rRNA gene sequences differentiated the new species among Trichodorus species from Europe, Asia and USA which formed a large clade. A review of the distribution of Trichodorus, Nanidorus and Paratrichodorus species revealed that T. cedarus, T. nanjingensis, T. pakistanensis and P. porosus are the most widespread species recorded from different provinces of China. This is the first extensive study of trichodorid species occurring in China.

Morphostatic Speciation within the Dagger Nematode Xiphinema hispanum-Complex Species (Nematoda: Longidoridae).

Dagger nematodes of the genus Xiphinema include a remarkable group of invertebrates of the phylum Nematoda comprising ectoparasitic animals of many wild and cultivated plants. Damage is caused by direct feeding on root cells and by vectoring nepoviruses that cause diseases on several crops. Precise identification of Xiphinema species is critical for launching appropriate control measures. We deciphered the cryptic diversity of the Xiphinema hispanum-species complex applying integrative taxonomical approaches that allowed us to verify a paradigmatic example of the morphostatic speciation and the description of a new species, Xiphinema malaka sp. nov. Detailed morphological, morphometrical, multivariate and genetic studies were carried out, and mitochondrial and nuclear haploweb analyses were used for species delimitation of this group. The new species belongs to morphospecies Group 5 from the Xiphinema nonamericanum-group species. D2-D3, ITS1, partial 18S, and partial coxI regions were used for inferring the phylogenetic relationships of X. malaka sp. nov. with other species within the genus Xiphinema. Molecular analyses showed a clear species differentiation not paralleled in morphology and morphometry, reflecting a clear morphostatic speciation. These results support the hypothesis that the biodiversity of dagger nematodes in southern Europe is greater than previously assumed.

Morphological and molecular characterization of Hemicycliophora subbotini n. sp. (Tylenchida: Hemicycliophoridae) from China.

Sheath nematodes of the genus Hemicycliophora are migratory root-ectoparasites of many crops, but the damage is documented for only a few species. Hemicycliophora subbotini n. sp., isolated in Hangzhou, Zhejiang, China, from the rhizosphere of camphor tree (Cinnamomum camphora (L.) Presl), is described and characterized morphologically and molecularly with important morphological details elucidated by SEM studies. The new species can be characterized by the conoid lip region, with bulging oral disc protruding beyond the first annulus in some specimens. Oral disc narrow ovate, amphidial apertures covered by lateral plates, lying in the same plane as oral disc when observed en face. Stylet 118 (108-125) µm long and flexible, stylet knobs concave shaped having a slight cavity. The excretory pore is located 1-2 annuli posterior to the base of pharyngeal bulb. Vulval lips slightly modified with small vulval sleeve, spermatheca rounded to oblong. Anus located 18 (15-22) annuli posterior to vulva. Tail elongated, with conoid or slightly offset spike having a narrowly rounded terminus. The study provides the first description of a new Hemicycliophora species from China. Phylogenetic analyses based on D2-D3 expansion segments of the 28S and ITS fragments revealed the new species forming a separate clade from other Hemicycliophora species which supported the status as a new species of this genus.