Problems with the taxonomy of Phytoptus tetratrichus Nalepa 1890 (Acari: Eriophyoidea) inhabiting Tilia spp.: Analysis based on morphological variation among individuals

Zootaxa ◽  
2011 ◽  
Vol 2988 (1) ◽  
pp. 37 ◽  
Author(s):  
GRAŻYNA SOIKA ◽  
MARCIN KOZAK
Keyword(s):  
Leaf Surface ◽  
Leaf Roll ◽  
Morphological Characters ◽  
Canonical Variate ◽  
Qualitative And Quantitative ◽  
Growing Seasons ◽  
Leaf Surfaces ◽  
Tilia Tomentosa ◽  
Two Populations ◽  
Damage Symptoms

The purpose of this research was to investigate both the qualitative and quantitative morphological traits of Phytoptus tetratrichus Nalepa 1890 populations inhabiting three different lime tree species: Tilia cordata Mill., Tilia tomentosa Moench and Tilia americana L.. Morphological characters of two populations collected from T. cordata and T. tomentosa over three successive growing seasons were compared with the aid of canonical variate analysis. Additionally, individuals occurring on T. americana in a consecutive year were also studied. Protogyne and deutogyne females were differentiated using both qualitative and quantitative traits. For deutogyne females, individuals from all combinations of Tilia species × year (which constituted populations for comparison) clearly differed from each other. However, the differences between populations from T. cordata and T. tomentosa were less distinct. For protogyne females, observed differences were clearly visible. The between-season variation in morphological characters such as body size appeared to be quite large, indicating that morphological analysis based on observations from only a single season can be inaccurate. Deutogyne females of P. tetratrichus were observed to cause various types of damage symptoms: leaf-roll galls along the leaf edges of T. cordata; small round erinea on the lower leaf surface and small wart-like galls on the upper leaf surface of T. tomentosa; fingerlike galls on both leaf surfaces of T. americana.

scholarly journals Study on diversity of foliar trichomes in thirty accessions of okra (Abelmoschus esculentus (L.) Moench.)

2018 ◽  
Author(s):  
K. Krishnakumar ◽  
P. Rajeena ◽  
V. Veena
Keyword(s):  
Morphological Characters ◽  
Variable Density ◽  
Abelmoschus Esculentus ◽  
Vegetative Stage ◽  
Breeding Programme ◽  
Qualitative And Quantitative ◽  
Leaf Surfaces ◽  
Epidermal Features ◽  
Micromorphological Characters

Foliar epidermal features of thirty accessions of okra (Abelmoschus esculentus) were studied with the aim of using these features to identify them in the vegetative stage during hybridization experiments. Quantitative and qualitative micromorphological characters, distribution of both glandular and eglandular foliar trichomes in thirty accessions of okra were characterized. An indumentum of variable density and texture formed of wide variety of glandular and eglandular trichomes on both surfaces of leaves. Among the thirty accessions of okra studied, both glandular and eglandular foliar trichomes showed considerable diversity in their qualitative and quantitative micro morphological characters. Diversity of these epidermal appendages is separated into eight main types. Eglandular conical type trichomes were the most abundant on both leaf surfaces of all the accessions examined. Accessions like Pusasawani and IC-117251 could be demarked due to the occurance of stellate trichomes. Forked type was delimited to accessions like Arkaanamika, IC-99746, IC-111514 and IC-111517. These variations in morphology and distribution of the foliar trichomes emerged as an important tool to identify the diverse accessions of okra during breeding programme.

Particle size, leaf pubescence and condition of humidity at leaf surfaces are key factors determining the retention of volcanic ash on crop foliage.

2021 ◽  
Author(s):  
Noa Ligot ◽  
Benoît Pereira ◽  
Patrick Bogaert ◽  
Guillaume Lobet ◽  
Pierre Delmelle
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Leaf Surface ◽  
Volcanic Risk ◽  
Chilli Pepper ◽  
Leaf Pubescence ◽  
Leaf Surfaces ◽  
Plant Foliage ◽  
Leaf Surface Area ◽  
Ash Deposit

<p>Volcanic ashfall negatively affects crops, causing major economic losses and jeopardising the livelihood of farmers in developing countries where agriculture is at volcanic risk. Ash on plant foliage reduces the amount of incident light, thereby limiting photosynthesis and plant yield. An excessive ash load may also result in mechanical plant damages, such as defoliation and breakage of the stem and twigs. Characterising crop vulnerability to ashfall is critical to conduct a comprehensive volcanic risk analysis. This is normally done by describing the relationship between the ash deposit thickness and the corresponding reduction in crop yield, i.e. a fragility function. However, ash depth measured on the ground surface is a crude proxy of ash retention on plant foliage as this metrics neglects other factors, such as ash particle size, leaf pubescence and condition of humidity at leaf surfaces, which are likely to influence the amount of ash that stays on leaves.</p><p>Here we report the results of greenhouse experiments in which we measured the percentage of leaf surface area covered by ash particles for one hairy leaf plant (tomato, Solanum lycopersicum L.) and one hairless leaf plant (chilli pepper, Capsicum annuum L.) exposed to simulated ashfalls. We tested six particle size ranges (≤ 90, 90-125, 125-250, 250-500, 500-1000, 1000-2000 µm) and two conditions of humidity at leaf surfaces, i.e. dry and wet. Each treatment consisted of 15 replicates. The tomato and chilli pepper plants exposed to ash were at the seven- and eight-leaf stage, respectively. An ash load of ~570 g m<sup>-2 </sup>was applied to each plant using a homemade ashfall simulator. We estimated the leaf surface area covered by ash from pictures taken before and immediately after the simulated ashfall. The ImageJ software was used for image processing and analysis.</p><p>Our results show that leaf coverage by ash increases with decreasing particle size. Exposure of tomato and chilli pepper to ash ≤ 90 μm always led to ~90% coverage of the leaf surface area. For coarser particles sizes (i.e. between 125 and 500 µm) and dry condition at leaf surfaces, a significantly higher percentage (on average 29 and 16%) of the leaf surface area was covered by ash in the case of tomato compared to chilli pepper, highlighting the influence of leaf pubescence on ash retention. In addition, for particle sizes between 90 and 500 µm, wetting of the leaf surfaces prior to ashfall enhanced the ash cover by 19 ± 5% and 34 ± 11% for tomato and chilli pepper, respectively.</p><p>These findings highlight that ash deposit thickness alone cannot describe the hazard intensity accurately. A thin deposit of fine ash (≤ 90 µm) will likely cover the entire leaf surface area, thereby eliciting a disproportionate effect on plant foliage compared to a thicker but coarser deposit. Similarly, for a same ash depth, leaf pubescence and humid conditions at the leaf surfaces will enhance ash retention, thereby increasing the likelihood of damage. Our study will contribute to improve the reliability of crop fragility functions used in volcanic risk assessment.</p>

Lack of Internalization of Escherichia coli O157:H7 in Lettuce (Lactuca sativa L.) after Leaf Surface and Soil Inoculation

2009 ◽  
Vol 72 (10) ◽  
pp. 2028-2037 ◽  
Author(s):  
GUODONG ZHANG ◽  
LI MA ◽  
LARRY R. BEUCHAT ◽  
MARILYN C. ERICKSON ◽  
VANESSA H. PHELAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Leaf Surface ◽  
Escherichia Coli O157 ◽  
Adaxial Side ◽  
Abaxial Side ◽  
E Coli ◽  
Lactuca Sativa L ◽  
Leaf Surfaces ◽  
Leaves And Roots ◽  
Leaf Lettuce

Survival and internalization characteristics of Escherichia coli O157:H7 in iceberg, romaine, and leaf lettuce after inoculation of leaf surfaces and soil were determined. A five-strain mixture of E. coli O157:H7 in water and cow manure extract was used as an inoculum for abaxial and adaxial sides of leaves at populations of 6 to 7 log and 4 log CFU per plant. The five strains were individually inoculated into soil at populations of 3 and 6 log CFU/g. Soil, leaves, and roots were analyzed for the presence and population of E. coli O157:H7. Ten (4.7%) of 212 samples of leaves inoculated on the adaxial side were positive for E. coli O157:H7, whereas 38 (17.9%) of 212 samples inoculated on the abaxial side were positive. E. coli O157:H7 survived for at least 25 days on leaf surfaces, with survival greater on the abaxial side of the leaves than on the adaxial side. All 212 rhizosphere samples and 424 surface-sanitized leaf and root samples from plants with inoculated leaves were negative for E. coli O157:H7, regardless of plant age at the time of inoculation or the location on the leaf receiving the inoculum. The pathogen survived in soil for at least 60 days. Five hundred ninety-eight (99.7%) of 600 surface-sanitized leaf and root samples from plants grown in inoculated soil were negative for E. coli O157:H7. Internalization of E. coli O157:H7 in lettuce leaves and roots did not occur, regardless of the type of lettuce, age of plants, or strain of E. coli O157:H7.

scholarly journals Character evolution of modern fly-speck fungi and implications for interpreting thyriothecial fossils

2020 ◽  
Author(s):  
Ludovic Le Renard ◽  
André L. Firmino ◽  
Olinto L. Pereira ◽  
Ruth A. Stockey ◽  
Mary. L. Berbee
Keyword(s):  
Morphological Evolution ◽  
Morphological Characters ◽  
Small Subunit ◽  
Leaf Surfaces ◽  
The Matrix ◽  
Character Matrix ◽  
Phylogenetic Framework ◽  
Single Hypha ◽  
Objective Basis ◽  
Ancestral Character States

AbstractPREMISE OF THE STUDYFossils show that fly-speck fungi have been reproducing with small, black thyriothecia on leaf surfaces for ∼250 million years. We analyze morphological characters of extant thyriothecial fungi to develop a phylogenetic framework for interpreting fossil taxa.METHODSWe placed 59 extant fly-speck fungi in a phylogeny of 320 Ascomycota using nuclear ribosomal large and small subunit sequences, including newly determined sequences from nine taxa. We reconstructed ancestral character states using BayesTraits and maximum likelihood after coding 11 morphological characters based on original observations and literature. We analyzed the relationships of three previously published Mesozoic fossils using parsimony and our morphological character matrix, constrained by the molecular phylogeny.KEY RESULTSThyriothecia evolved convergently in multiple lineages of superficial, leaf- inhabiting ascomycetes. The radiate and ostiolate scutellum organization is restricted to Dothideomycetes. Scutellum initiation by intercalary septation of a single hypha characterizes Asterinales and Asterotexiales, and initiation by coordinated growth of two or more adjacent hyphae characterizes Aulographaceae (order incertae sedis). Scutella in Microthyriales are initiated apically on a lateral hyphal branch. Patterns of hyphal branching in scutella contribute to distinguishing among orders. Parsimony resolves three fossil taxa as Dothideomycetes; one is further resolved as a member of a Microthyriales-Zeloasperisporiales clade within Dothideomycetes.CONCLUSIONSThis is the most comprehensive systematic study of thyriothecial fungi and their relatives to date. Parsimony analysis of the matrix of character states of modern taxa provides an objective basis for interpreting fossils, leading to insights into morphological evolution and geological ages of Dothideomycetes clades.

scholarly journals Mitotic Golgi clusters are not tubular endosomes

1993 ◽  
Vol 104 (3) ◽  
pp. 811-818 ◽  
Author(s):  
M. Pypaert ◽  
T. Nilsson ◽  
E.G. Berger ◽  
G. Warren
Keyword(s):  
Hela Cell ◽  
Endocytic Pathway ◽  
Hela Cell Line ◽  
Frozen Sections ◽  
Qualitative And Quantitative ◽  
Quantitative Studies ◽  
Cell Biol ◽  
Endogenous Protein ◽  
Secondary Antibodies ◽  
Two Populations

HeLa cells were incubated with 15 nm BSA-gold for 1 or 2 hours to mark the endocytic pathway and mitotic cells were then isolated by shake-off. Thin, frozen sections were labelled with antibodies against two resident Golgi markers, beta-(1,4)-galactosyltransferase and N-acetylglucosaminyltransferase I. Detection of the latter was aided by the use of a HeLa cell line stably expressing a myc-tagged version of the endogenous protein. The secondary antibodies were coupled to either 5 or 10 nm gold so that the distribution of each of the three markers could be followed. Qualitative and quantitative studies showed that there were two populations of clusters, those described by us earlier and termed Golgi clusters (Lucocq et al. (1987) J. Cell Biol. 104, 865–874), containing either or both Golgi markers, and clusters of tubular endosomes containing BSA-gold. There was very little overlap showing that Golgi clusters cannot be tubular endosomes as concluded by Tooze and Hollinshead (1992) Eur. J. Cell Biol. 58, 228–242.

Genetic variation between and within two populations of Trifolium glomeratum (cluster clover) in Western Australia

1997 ◽  
Vol 48 (7) ◽  
pp. 969 ◽  
Author(s):  
Sarita Jane Bennett
Keyword(s):  
Cluster Analysis ◽  
Genetic Variation ◽  
Western Australia ◽  
Morphological Characters ◽  
Field Station ◽  
Site Variation ◽  
Components Analysis ◽  
And Cluster Analysis ◽  
The University ◽  
Two Populations

Genetic variation between and within populations of Trifolium glomeratum (cluster clover) was studied using seed collected from 2 sites in Western Australia: Mount Barker in the south and Kwelkan in the wheatbelt. Seed was collected at 64 subplots within each site and the material was grown at the University Field Station at Shenton Park, Perth. Seventeen morphological characters were scored and the results were analysed using analysis of variance, principal components analysis, and cluster analysis. Within-site variation was much greater than had previously been shown, and a considerable amount of between-site variation was present. It is suggested that within-site variation is due to a small amount of heterozygosity, as a result of limited outbreeding, being present in each population. The 2 populations are shown to be distinct from each other, with the population from Mount Barker containing more within-site variation. It is suggested that this is a result of climatic stress influencing and reducing the amount of variation being maintained in the Kwelkan population.

The atmospheric conditions affecting sporulation of blue mould in tobacco

1964 ◽  
Vol 4 (13) ◽  
pp. 178 ◽  
Author(s):  
BG Collins
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Critical Parameter ◽  
Leaf Surface ◽  
Atmospheric Conditions ◽  
Blue Mould ◽  
Growing Seasons ◽  
Ambient Relative Humidity ◽  
Critical Relative Humidity

Conditions favouring sporulation of blue mould (Peronospora tabacina Adam) having been established in the laboratory, a theoretical model has now been used to express the critical parameter, i.e. the relative humidity near the leaf surface where the spores form, in terms of the ambient atmospheric conditions. To test the validity of this model, wind speed, air temperature, and relative humidity mere measured over four growing seasons in three tobacco crops in the Ovens Valley, Victoria, and related to times of sporulation of the mould observed concurrently in these crops. 'Critical relative humidity,' a function of wind speed, air temperature, and heat loss from the crop is shown to be a more serviceable indicator of likelihood of sporulation than either ambient relative humidity or rainfall.

scholarly journals Summer Diet of Two White-tailed Deer, Odocoileus virginianus, Populations Living at Low and High Density in Southern Québec

2004 ◽  
Vol 118 (3) ◽  
pp. 360 ◽  
Author(s):  
Claude Daigle ◽  
Michel Crête ◽  
Louis Lesage ◽  
Jean-Pierre Ouellet ◽  
Jean Huot
Keyword(s):  
Odocoileus Virginianus ◽  
Feeding Habits ◽  
High Density ◽  
Rumen Content ◽  
Régime Alimentaire ◽  
Food Items ◽  
Growing Seasons ◽  
Content Analyses ◽  
Two Populations ◽  
Foraging Time

We investigated summer diets of two White-tailed Deer (Odocoileus virginianus) populations through rumen content analyses. Samples from 93 deer were collected in a low density, LD (1 deer/km2) and a high density, HD (14 deer/km2) area of southern Québec during the growing seasons of 1997 and 1998. Availability of preferred forage in forests was greater in LD than in HD, whereas agriculture covered a larger proportion of the area in HD than LD. Rumen composition differed between the two populations. Deer from HD consumed less forbs and leaves of shrubs and trees than did LD deer, whereas they consumed more fruits, grasses and farm crops. The rarity in HD rumens of food items common in LD, as well as in many parts of the White-tailed Deer range (i.e., Lilliacae), indicated that deer could not compensate for the rarity of preferred forest forage by increasing foraging time and had to feed on cultivated crops. Rumen contents of LD deer had a higher level of cell solubles and lignin, which reflected their greater reliance on quality forage growing in forests. Feeding habits and forage quality can explain why deer body size decreased in HD between the 1970s and 1990s whereas LD deer remained large.Nous avons examiné le régime alimentaire estival de deux populations de cerf de Virginie (Odocoileus virginianus) par l’analyse du contenu des rumens. Des échantillons ont été prélevés sur 93 cerfs provenant d’un secteur à faible densité de cerfs, LD, (1 cerf/km2) et d’un secteur à haute densité, HD, (14 cerfs/km2) du sud du Québec durant la saison de croissance des végétaux de 1997 et 1998. La disponibilité des aliments forestiers préférés des cerfs était plus grande dans LD que dans HD alors que la proportion du territoire agricole était supérieure dans HD. La composition des rumens des cerfs de chacune des régions différait. Les cerfs de HD ont consommé de moins grandes proportions de plantes herbacées et de feuilles d’arbustes et d’arbres que ceux du secteur LD, mais de plus grandes proportions de fruits, de graminées et de plantes agricoles. La rareté dans les rumens du secteur HD d’aliments communs dans ceux du secteur LD et dans plusieurs autres régions de l’aire de répartition du cerf (e.g., Lilliacae), indique que les cerfs du secteur HD ne pouvaient compenser pour la rareté de leurs aliments préférés par un accroissement de la durée de la quête alimentaire, et qu’ils devaient consommer des plantes agricoles. Les cerfs de LD ont mangé des aliments contenant plus de solubles cellulaires et de lignine que ceux de HD, ce qui reflète une consommation de plantes forestières de bonne qualité. Le régime alimentaire et la qualité de la nourriture peuvent expliquer pourquoi la taille des cerfs de HD a diminué entre les années 1970 et 1990 alors que celle des cerfs de LD est demeurée grande.

Paris lihengiana (Melanthiaceae: Parideae), a new species from Yunnan, China

Phytotaxa ◽  
2019 ◽  
Vol 392 (1) ◽  
pp. 45 ◽  
Author(s):  
ZHUN XU ◽  
NENG WEI ◽  
YING TAN ◽  
SHUAI PENG ◽  
VERONICAH MUTELE NGUMBAU ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Yunnan Province ◽  
Leaf Surface ◽  
Morphological Characters ◽  
Molecular Data ◽  
Abaxial Leaf Surface ◽  
Molecular Phylogenetic ◽  
Plastid Markers ◽  
A New Species

Paris lihengiana (Melanthiaceae), a new species from Yunnan Province, China, is described and illustrated based on evidence from morphological characters and molecular phylogeny. It differs from other species of Paris in its pubescent stem, pedicel and abaxial leaf surface, as well as other characters. Molecular phylogenetic analysis of 33 taxa in Paris was conducted based on nuclear ribosomal ITS and six plastid markers. Paris lihengiana is supported as a new species by both morphological characters and molecular data.

scholarly journals Cryptic Species Discrimination in Western Pine Beetle, Dendroctonus brevicomis LeConte (Curculionidae: Scolytinae), Based on Morphological Characters and Geometric Morphometrics

Insects ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 377
Author(s):  
Osiris Valerio-Mendoza ◽  
Jazmín García-Román ◽  
Moises Becerril ◽  
Francisco Armendáriz-Toledano ◽  
Gerardo Cuéllar-Rodríguez ◽  
...  
Keyword(s):  
Morphological Characters ◽  
Canonical Variate ◽  
Dendroctonus Brevicomis ◽  
Group Differences ◽  
Species Discrimination ◽  
Geometric Morphometric ◽  
Western Pine Beetle ◽  
Principal Coordinates ◽  
The Pacific ◽  
Pine Beetle

The western pine beetle (WPB), Dendroctonus brevicomis LeConte, is a major mortality agent of pines in North America. A total of 706 adults of WPB from 81 geographical sites were analyzed with traditional and geometric morphometric methods to evaluate the variation of discrete and quantitative morphological characters with particular attention to the antenna, spermatheca, and seminal rod. Principal coordinates and canonical variate analyses supported three geographical groups in WPB: (1) West, from British Columbia to southern California along the Pacific coast, Idaho, and Montana; (2) East-SMOC, including Nevada, Utah, Colorado, Arizona, New Mexico, Texas, Chihuahua, and Durango; and (3) SMOR, including Coahuila, Nuevo Leon, and Tamaulipas. The pubescence length on the elytral declivity was a robust character for separating West specimens from the other groups. Additionally, the genitalia shape both female and male in dorsal view was a reliable character for discriminating among groups. Based on these results, which agree with genetic and chemical ecology evidence, we herein reinstate Dendroctonus barberi Hopkins (East-SMOC group) and remove it from synonymy with D. brevicomis (West group). Differences in the spermatheca and seminal rod shape of SMOR specimens suggest that these populations might be a different species from D. barberi and D. brevicomis.

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