The use of low-temperature scanning electron microscopy (LTSEM) to study external mouthpart morphology in the Tenuipalpidae, in particular the genus Raoiella, has brought some aspects of the ...mechanics of feeding in this group into question. In addition, an LTSEM study on the specialized feeding behaviour of Raoiella indica Hirst (Tetranychoidea: Tenuipalpidae) revealed host plant use in this species could be affected by stomatal complex morphology.
A new species of Tenuipalpus, T. sarcophilus n. sp. (Tenuipalpidae) is described from specimens collected from several species of ornamental succulent plants in Florida, including Crassula tetragona ...L, Sedum spp., Echeveria spp., Pachyphytum spp. (Crassulaceae) and Aloe spp. (Asphodelaceae), and from specimens intercepted in USA on Echeveria gibbiflora from Guatemala. The feeding damage and possible origin of T. sarcophilus n. sp. is discussed. Tenuipalpus crassulu Baker and Tuttle 1972 is redescribed based on females, deutonymphs and a protonymph remounted from the original type series. The pattern of additions of leg setae through ontogenetic development is presented for T. sarcophilus n. sp. and discussed in relation to related tenuipalpid taxa and the Tetranychidae. A list of Tenuipalpus currently known from Florida is presented.
http://zoobank.org/urn:lsid:zoobank:zoobank.org:pub:695E5768-97A7-45B6-9CD1-B3E3D680AD93
Puccinia horiana, causal agent of the disease commonly known as chrysanthemum white rust (CWR), is a quarantine-significant fungal pathogen of chrysanthemum in the United States and indigenous to ...Asia. The pathogen was believed to have been eradicated in the United States but recently reappeared on several occasions in northeastern United States. The objective of the study presented here was to determine whether P. horiana could systemically infect chrysanthemum plants, thus providing a means of survival through winters. Scanning and transmission electron microscopy revealed the development of P. horiana on the surface and within leaves, stems, or crowns of inoculated chrysanthemum plants artificially exposed to northeastern U.S. winter temperatures. P. horiana penetrated leaves directly through the cuticle and then colonized the mesophyll tissue both inter- and intracellularly. An electron-dense material formed at the interface between fungal and host mesophyll cells, suggesting that the pathogen adhered to the plant cells. P. horiana appeared to penetrate mesophyll cell walls by enzymatic digestion, as indicated by the absence of deformation lines in host cell walls at penetration sites. The fungus was common in vascular tissue within the infected crown, often nearly replacing the entire contents of tracheid cell walls. P. horiana frequently passed from one tracheid cell to an adjacent tracheid cell by penetration either through pit pairs or nonpitted areas of the cell walls. Individual, presumed, fungal cells in mature tracheid cells of the crown and stems arising from infected crowns suggested that the pathogen might have been moving at least partially by means of the transpiration stream. The demonstration that chrysanthemum plants can be systemically infected by P. horiana suggests that additional disease control measures are required to effectively control CWR.
Simple sequence repeat (SSR), or microsatellite markers, are codominant, abundant and hypervariable molecular markers from eukaryotic genomes that are being widely used in genetic mapping, ...phylogenetic studies, and marker-assisted selection. Currently, the number of SSR markers available from alfalfa (Medicago sativa L.) genomic libraries is limited. This study was conducted to identify additional SSR markers in the alfalfa genome and to evaluate their ability to separate the nine historically recognized progenitors of North American cultivated alfalfa (African, Chilean, Falcata, Flemish, Indian, Ladak, Peruvian, Turkistan, and Varia), as well as seven additional accessions of M. sativa ssp. sativa, falcata, and coerulea and the model legume M. truncatula. Genomic DNA from the autotetraploid alfalfa germplasm W10 was used to develop 81 primer pairs, which amplified SSRs containing AC, AT, CT, CTT, GAT, and GGT motifs. The majority (96%) of the primer pairs were functional and 61 (78.2%) detected 2 to 11 polymorphic fragments among the accessions. A dendrogram was constructed using cluster analysis from these data, representing three main clusters: (i) diploid ssp. falcata; (ii) M. truncatula; and (iii) all remaining entries. Additional separation of some accessions M. truncatula (‘Jemalong’), Ladak (‘Ladak’), Fall dormancy 11 (UC-1465), Indian (Sirsa Type 9), Flemish (‘Dupuit’), Peruvian (‘Hairy Peruvian’), and African 2 (‘Moapa’) was obtained through multiple correspondence analysis. These genomic alfalfa SSRs have excellent utility for polymorphic assessment with potential application for phylogenetic and genetic mapping studies of alfalfa.
ICTV Virus Taxonomy Profile: Baculoviridae Harrison, Robert L; Herniou, Elisabeth A; Jehle, Johannes A ...
Journal of general virology,
09/2018, Letnik:
99, Številka:
9
Journal Article
Recenzirano
Odprti dostop
The family Baculoviridae comprises large viruses with circular dsDNA genomes ranging from 80 to 180 kbp. The virions consist of enveloped, rod-shaped nucleocapsids and are embedded in distinctive ...occlusion bodies measuring 0.15-5 µm. The occlusion bodies consist of a matrix composed of a single viral protein expressed at high levels during infection. Members of this family infect exclusively larvae of the insect orders Lepidoptera, Hymenoptera and Diptera. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Baculoviridae, which is available at www.ictv.global/report/baculoviridae.
To make elocient use of large germplasm collections, it is advisable to assemble a representative core collection and to evaluate the relationships among the traits studied. However, the assemblage ...of a core collection from very large germplasm collections is problematic. The computing resources needed to carry out genetic distance calculations and comparisons with commonly available programs is prohibitively large. The objects of this study were (i) to develop a method which assembles a core collection by maximizing the diversity (measured as mean Euclidean distance) from within groups of accessions defined by species, subspecies, and geographic origin and (ii) to test the effectiveness of the method on a collection of 20997 annual Medicago accessions from the Australian Medicago Resource Center in Adelaide, South Australia, that had been evaluated for 27 agronomic characteristics. The method resulted in a core collection of 1705 accessions that represented 74% of the extremes of the 27 characters, indicating that the entire range of the characters was represented in most cases. Accessions representing the extremes easily could be added to the core collection. The method used requires relatively minor computing resources and should be useful to curators of large germplasm collections. To assess the relationships among the 27 measured traits, correlation coefficients of all possible combinations of traits were calculated. The most strongly associated traits were, as expected, such traits as grams of seed per plant and grams of pods per plant and indicated that some traits could be omitted from future evaluations with little loss of information, thereby increasing the efficiency with which germplasm evaluations can be carried out.
Travelling with tea: a Tuckerella’s tale Beard, J. J.; Ochoa, R.; Childers, C. C. ...
Experimental & applied acarology,
02/2013, Letnik:
59, Številka:
1-2
Journal Article
Recenzirano
Tuckerella japonica
Ehara appears strongly associated with tea (
Camellia sinensis
(L.) Kuntze, Theaceae) and, due to certain cultural practices in tea production, has in fact become a world ...traveller, accompanying the greatly coveted tea plant as it spread across the planet. The history of tea production and culture, and its arrival in the USA, provides the backdrop for this traveller’s tale.
Tuckerella japonica
is morphologically similar to
T. flabellifera
Miller, described from Tasmania in Australia from
Bedfordia salicina
(Labill.) D.G. (Asteraceae). These two species have historically been misidentified as each other, creating inaccuracies in the collection records. The implications of this in terms of host plant lists and world distribution are discussed further, along with their morphological separation. The male and immature stages of
T. japonica
are described for the first time.
Tuckerella xinglongensis
Lin and Fu, from tea in China, is considered a junior synonym of
T. japonica
. The loss of the ancestral prostigmatan condition of three nymphal stages during ontogeny is confirmed for males of
T. flabellifera
, which do not retain a tritonymphal stage.
Specimen vouchering is a critical aspect of systematics, especially in genetic studies where the identity of a DNA sample needs to be assured. It can be difficult to obtain a high quality voucher ...after DNA extraction when dealing with tiny and delicate invertebrates that often do not survive the extraction procedure intact. Likewise, once a whole specimen has been extracted from, it is no longer useful for scanning electron microscopic examination. This paper discusses the use of a single specimen for both low temperature scanning electron microscopy and DNA extraction. This process allows full documentation of all external characteristics of an organism and ample whole genomic DNA extraction for DNA sequencing.
Mammalian sperm bind to terminal carbohydrates associated with glycoconjugates on the apical surface of oviduct epithelial cells in the caudal region of the oviduct and undergo cellular and molecular ...modifications associated with capacitation prior to ovulation. In contrast, chicken sperm are stored for up to 23 d in sperm-storage tubules (SST) localized in the uterovaginal junction (UVJ). Little is known of the cellular and molecular mechanisms that regulate sperm storage in and release from the SST. The purpose of this study was to identify glycoconjugates associated with the SST epithelial cell surface using lectins. Virgin hens and hens of higher and lower fertility in egg production for 6 to 16 wk were used in this study. Sections of UVJ mucosa containing SST were stained with fluorescent conjugated lectins and examined by confocal microscopy. Carbohydrate moieties associated with the UVJ and SST epithelia differed in their lectin binding patterns. No differences in the lectin binding patterns within the 2 epithelia were discernible between the virgin and younger and older hens. Minor differences were observed between the higher and lower fertility hens. Only lectins specific for galactose and N-acetylgalactosamine moieties were localized to the luminal surface of the SST. While resident sperm may be closely apposed to the SST epithelial cell apical microvilli, it is unlikely that sperm binding to the microvilli via terminal carbohydrates associated with glycoconjugates is a requisite for prolonged storage. However, the possibility of SST epithelial cell communication with resident sperm via shedding microvillous vesicles characterized by surface glycoconjugates with terminal galactose and N-acetylgalactosamine moieties is currently being investigated.
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