scholarly journals SEDIMENTATION VELOCITY OF POLLEN PARTICLES OF ANEMOPHILIC PLANTS GROWING ON TERRITORY OF THE CSBG SB RAS

2021 ◽  
Vol 4 (2) ◽  
pp. 43-49
Author(s):  
Vladimir V. Golovko ◽  
Konstantin A. Khlebus ◽  
Galina A. Zueva

The settling of pollen particles of four species of anemophilic plants ( Populus alba L., Salix hybrida , Miscanthus sinensis Andersson, Chosenia arbutifolia (Pall.) A. K. Skvortsov) growing in the exposition of the CSBS SB RAS was investigated. These species are widely used in landscaping cities of the Novosibirsk region and are producers of impressive amounts of allergenic pollen, which can be carried by the wind over significant distances. The presence of a significant proportion of clusters, which include two or more pollen grains, is shown. Settling rates were determined as individual pollen grains of these plant species and their clusters, which included from two to six pollen grains. Dependence of cluster sedimentation rate on number of pollen grains included in it is established.

2018 ◽  
Vol 34 (4) ◽  
pp. 281-290 ◽  
Author(s):  
Benjamin E. McMillan ◽  
Jake E. Bova ◽  
Carlyle C. Brewster ◽  
Nicola T. Gallagher ◽  
Sally L. Paulson

ABSTRACT The effect of 5 plant species (arborvitae [Thuja occidentalis], boxwood [Buxus sp., Japanese honeysuckle [Lonicera japonica], rhododendron [Rhododendron sp.], and zebra grass [Miscanthus sinensis]) and 2 rates of lambda-cyhalothrin (3.13 ml and 6.25 ml active ingredient [AI]/liter) on knockdown (1 h) and mortality (24 h) of adult female Aedes albopictus was evaluated over an 8-wk period. A significant difference in knockdown was observed between the 2 rates of lambda-cyhalothrin on the 5 plant species, with the highest proportion of knockdown observed on zebra grass and rhododendron treated at the higher rate. Although mortality was ≥60% and 85% on the 5 plant species at the low and high rates of lambda-cyhalothrin, respectively, a significant difference between the 2 rates was only observed on boxwood and Japanese honeysuckle (P < 0.0001). We also tested the residual toxicity of 3 barrier sprays (lambda-cyhalothrin, bifenthrin, and deltamethrin) and evaluated the efficacy of a short (5-min) exposure to the insecticides on knockdown and mortality of adults over time. Significantly higher knockdown was observed with lambda-cyhalothrin compared with bifenthrin and deltamethrin (P < 0.0001). Mean knockdown was ∼98%, 92%, and 20% for lambda-cyhalothrin, bifenthrin, and deltamethrin, respectively, at week 2, and ∼98%, 0%, and 44%, respectively, 8 wk after treatments were applied. Adult mortality from the 3 chemical treatments, however, remained above 90% throughout the study. Lastly, the trends in mean proportion of knockdown were similar for mosquitoes exposed for either 5 min or 24 h to the 3 chemicals. An overall decline in mean mortality over time, however, was observed for mosquitoes exposed for 5 min to the chemicals compared with mortality from the 24-h exposure. The results suggest that lambda-cyhalothrin can be an effective barrier spray treatment against Ae. albopictus adults because its efficacy is limited little by plant species, it has long residual toxicity, and it is effective following only 5 min of exposure.


1998 ◽  
Vol 64 (11) ◽  
pp. 4460-4466 ◽  
Author(s):  
G. J. Medema ◽  
F. M. Schets ◽  
P. F. M. Teunis ◽  
A. H. Havelaar

ABSTRACT Experimental analysis of the sedimentation velocity ofCryptosporidium parvum oocysts and Giardia lamblia cysts was compared with mathematical description of their sedimentation velocities by using measurements of (oo)cyst size and density and the density and viscosity of the sedimentation medium to determine if the sedimentation kinetics of freely suspended oocysts ofC. parvum and cysts of G. lamblia can be described by Stokes’ law. The theoretically calculated sedimentation kinetics showed a good agreement with the experimentally observed kinetics. Both showed a decline in sedimentation velocity over time, caused primarily by variation in (oo)cyst density. The initial apparent sedimentation velocities in Hanks balanced salt solution at 23°C was 0.35 μm · s−1 for oocysts and 1.4 μm · s−1 for cysts. (Oo)cysts that enter the surface water environment by discharges of biologically treated sewage may be attached to sewage particles, and this will affect their sedimentation kinetics. Therefore, (oo)cysts were mixed with settled secondary effluent. (Oo)cysts readily attached to the (biological) particles in effluent; 30% of both cysts and oocysts attached during the first minutes of mixing, and this fraction increased to approximately 75% after 24 h. The sedimentation velocity of (oo)cysts attached to secondary effluent particles increased with particle size and was (already in the smallest size fraction [1 to 40 μm]) determined by the sedimentation kinetics of the effluent particles. The observed sedimentation velocities of freely suspended (oo)cysts are probably too low to cause significant sedimentation in surface water or reservoirs. However, since a significant proportion of both cysts and oocysts attached readily to organic biological particles in secondary effluent, sedimentation of attached (oo)cysts after discharge into surface water will probably be a significant factor in the environmental ecology ofC. parvum and G. lamblia. Attachment to particles influences not only sedimentation of (oo)cysts in surface water but also their behavior in drinking water treatment processes.


1976 ◽  
Vol 143 (5) ◽  
pp. 1220-1238 ◽  
Author(s):  
J M Fidler ◽  
M C Howard ◽  
K Shortman

The characteristics of antibody-forming cell (AFC) progenitors lacking previous contact with specific antigen (virgin AFC progenitors) has been studied using sedimentation velocity and buoyant density separation for the investigation of physically distinct B-cell subpopulations. Functional characterization of isolated subsets was made using a quantitative adoptive immune assay for the IgM AFC progenitors responding to the antigen 4-hydroxy-3-iodo-5-nitrophenylacetic acid conjugated polymerized bacterial flagellin. Extensive heterogeneity is present among B lymphocytes, only some subpopulations of which exhibit AFC progenitor function. In the spleen of adult conventional CBA mice, atypically fast sedimenting cells of low buoyant density are active, while typical small B lymphocytes do not appear to be progenitors of IgM AFC. Spleen of adult specific pathogen-free (SPF), germfree, and athymic nude mice give similar results, although a minor population of typical slowly sedimenting dense cells are active in the latter two sources. Adult conventional bone marrow cells are as physically and functionally heterogeneous as splenic B cells, and although a significant proportion of AFC progenitor activity is found among dense, slowly sedimenting cells, most of the activity is among low density, faster sedimenting cells. In contrast to this situation in adult animals, where most of the unprimed AFC progenitors are large, atypical B cells, the spleens of neonatal mice provide a site where virgin AFC progenitors with the physical properties of typical small B lymphocytes are found. While being present in conventional and SPF neonatal spleens, these virgin cells are predominant in 7-day-old germfree mouse spleen. These findings suggest that the newborn virgin B cell is a typical small lymphocyte. However, few cells of this type are found in the adult animal. The unprimed AFC-progenitor population in the adult consists of large, fast sedimenting, low buoyant density, adherent cells, the physical properties of which are characteristic of activated B lymphocytes. It is suggested that these atypical cells are derived from the small newborn virgin B cell by the nonspecific effects of environmental antigenic stimuli.


2008 ◽  
Vol 24 (05) ◽  
pp. 477-484 ◽  
Author(s):  
Tuanjit Srithongchuay ◽  
Sara Bumrungsri ◽  
Ekapong Sripao-raya

Abstract:Although plant species that attract multiple species of pollinators predominate in tropical plant communities, pollination specialists appear to be at a greater advantage in tropical ecosystems in which pollinators are numerous and many plants flower synchronously. The present study determined the breeding system and legitimate pollinators ofOroxylum indicumVent. in Songkhla and Patthalung Provinces, Thailand.Oroxylum indicumexhibits steady-state flowering, with one or two flowers per inflorescence opening each night. Flowers open in the evening and drop off shortly after midnight, while its bilabiate stigma is highly sensitive, and quickly close upon being touched.Oroxylum indicumis self-incompatible. Hand-cross pollination and open pollination yielded the highest pollination success (47.7% and 31.2% respectively, n = 7 trees). About 900 pollen grains are needed for initiating fruit set. It is confirmed that a fruit bat,Eonycteris spelaea, is the legitimate pollinator. Bats are responsible for all pollen load and the pollen load from only one visit is generally sufficient to initiate fruit set. AlthoughEonycteris spelaeais effective, it is an inefficient pollinator. Compared with plant species pollinated by multiple animal species, the likelihood of pollination failure resulting from the decline in populations ofEonycteris spelaeawill be much more intense inOroxylum indicum.


2021 ◽  
Vol 21 (no 1) ◽  
Author(s):  
Maliarenko O.A. ◽  
Maliarenko O.A. ◽  
Maliarenko O.A. ◽  
Maliarenko O.A. ◽  
Maliarenko O.A. ◽  
...  

The work aimed at creating tetraploid lines of Miscanthus sinensis and Miscanthus sacchariflorus species. To achieve this goal, we used methods of microclonal propagation, fluorescence cytophotometry, and genomic status differentiation using computer software of AP ‘Partec’ (Germany). It was found that the percentage of cultivated shoots of Miscanthus sacchariflorus for an exposure period of 1 day was 18.86 ± 5.37%. To compare, it was51.78 ± 6.51% in Miscanthus sinensis. The best indicators of tetraploid induction in Miscanthus sinensis were observed for the exposure to colchicine for 2 days with polyploidization efficiency of 31.25% and 21.42%, and in Miscanthus sacchariflorusf or 2 hours and 6 hours with rates of 35.0% and 27.3%, respectively. To stabilize the tetraploid level of genome ploidy, we used Murashige and Skoog liquid media (1962) supplemented with 0.005% colchicine and an exposure period of myxoploids for 6 hours. The flowering of new tetraploid clones in the conditions of Ukraine was observed on the second year of vegetation in late September and the beginning of October with the formation of fertile pollen grains. However, development of a microgametophyte depends on temperature conditions, both for Miscanthus sinensis (4x) and Miscanthus sacchariflorus (4x). Breeding schemes for the formation of anisoploid populations have also been developed: M sinensis (4x) x M sinensis (2x); M. sa?chariflorus (4x) x M sinensis (2x); M sinensis (4x) x M. sachariflorus (2x)


Turczaninowia ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 12-18
Author(s):  
Elena Yu. Zykova ◽  
Tatyana V. Pankova (An’kova)

Chromosome numbers (2n) for 12 alien species (Apiaceae, Asteraceae, Brassicaceae, Campanulaceae, Fabaceae, Lamiaceae, Malvaceae, Onagraceae, Poaceae, Polygonaceae) from the Novosibirsk Region are given. For the first time for Russia, the number of chromosomes of Xanthogalum purpurascens (2n = 22) is given, for Siberia – Nepeta cataria (2n = 34), Malva pusilla (2n = 42) and Koenigia weyrichii subsp. weyrichii (2n = 20). For all studied species, short information on the general distribution and dispersal in the Novosibirsk Region, literature data on the number of chromosomes from the territory of Russia are presented.


2017 ◽  
Vol 48 (5) ◽  
Author(s):  
Al-Musawi & et al.

Present study delts with morphological and vegetative shoot apex characteristics of two species  Echinops armatus and E.cephalotes (compositae) which collected during trips field to the northern areas of Iraq in the seasons of growth 2012-2014. As it presents the results and characters  had been shown for the first time in Iraq. plant species are perennial herbs spinous with woody, strong and solid stems that covered with many types of indumentums like spines and hairs, the study included characters of stems, leaves, involucres bracts and inflorescences as well as characters of growing points of the two species, and by examining buds in inflorescences found that the flowers are hermaphrodite, not sterile which containing all the reproductive organs like stamens, pollen grains, pistils and ovaries, an early dehesence as mature anthers and bloom before the maturation of pistils and disperse their pollen.The study also discussed variations within the characters and it became clear that the characters of leaves, stems and involucres especially inner cycle, including the importance of taxonomic great isolate the two species. Ranged prepare involucres braces  in the first species is (20-23) bracts while the number varied between (19-20) bracts in the other one. The study showed the importance of growing points  in isolating the two species where characterized by two meristematic area in longitudinal embryos species. The first spices recognized by two rows of cells, while the other one marked three rows or layers of components of Tunica cells area, and ensures find accurate measurements of parts phenotypic as well as illustrations of morphological and anatomical parts studied.                   


2021 ◽  
Vol 13 (3) ◽  
pp. 840-845
Author(s):  
Rajwant Kaur ◽  
Manpreet Kaur ◽  
Avinash Kaur Nagpal ◽  
Jatinder kaur Katnoria

Polyphenols, the secondary metabolites distributed in different parts of a plant, have major role in protecting the plants from deleterious effects of ultraviolet radiations and various diseases caused by pathogens. Considering the fact that these metabolites possess tremendous medicinal properties, extensive research has been carried out during the past few decades to explore their potential health benefits. Further, polyphenols are documented to possess different activities such as antioxidant, anticarcinogenic, anti-inflammatory, antimicrobial and antiulcer. The present study pertained to analyze different polyphenolic compounds in pollen grains of 9 medicinally important plant species viz., Bauhinia variegata, B.purpurea, Cassia biflora, C. fistula, C. glauca, C. saimea and Delonix regia belonging to Fabaceae family, Hibiscus rosa-sinensis belonging to Malvaceae family and Melia azadirach belonging toMeliaceaefamily using Ultra high-performance liquid chromatography (UHPLC). Various polyphenolic compounds likecaffeic acid, catechin, chlorogenic acid, coumaric acid, ellagic acid, epicatechin, gallic acid, kaempferol, quercetin, rutin, tert-butyl hydroquinone andumbelliferonewere found to be present in the pollen grains of these plant species. The order of plant species in terms of maximum number of polyphenolic compounds was observed as Cassia saimea (10) > B. purpurea (9) = C. fistula (9) = Hibiscus rosa-sinensis (9) > Delonix regia (8) > B. variegata (6) > C. glauca (4) = Melia Azadirach (4) > C. biflora (3). The plants such as C. saimea, B. purpurea, C. fistula and H. rosa-sinensis with different polyphenolic compounds indicated their potential forthe treatment of ailments.


2008 ◽  
Vol 140 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Christopher J. Borkent ◽  
Evert I. Schlinger

AbstractAcroceridae is a family of spider-parasitic flies that often visit flowers as adults, although little is known about their possible role as pollinators. Eulonchus tristis Loew visiting flowers of Brodiaea elegans Hoover (Liliaceae s.l.) and Iris douglasiana Herbert (Iridaceae) were collected in California. Individuals carried large pollen loads, although visitors to B. elegans carried significantly more pollen grains than visitors to I. douglasiana. Visitors to B. elegans also carried a higher percentage of focal-plant pollen (91%) than visitors to I. douglasiana (38%). There was no difference in the diversity of pollen species (approximately nine) carried by visitors to either plant species. For visitors to B. elegans, no difference was seen in the amount or diversity of pollen carried with respect to the sex of the visitor. The behaviour potentially resulting in the acquisition of these pollen loads is discussed. These results show that E. tristis has the potential to be an important pollinator for these plant species, particularly B. elegans.


2021 ◽  
Vol 11 (2) ◽  
pp. 658
Author(s):  
Malvína Čierniková ◽  
Ivana Vykouková ◽  
Tomáš Orfánus ◽  
Elena Masarovičová

The landfill waste of leached ore residue represents a serious environmental risk and may also negatively affect the appearance, growth and development of vegetation. Here we focused on the evaluation of functional traits of selected plant species Populus alba, Calamagrostis epigejos, and Diplotaxis muralis growing in an unfavourable environment. We determined different adaptive strategies of selected species to extreme conditions. For Diplotaxis muralis the highest values of the leaf dry matter content (LDMC) and the lowest values of the specific leaf area (SLA) were determined, while for Calamagrostis epigejos these two traits correlated in opposite directions. Populus alba reached the lowest value of the water saturation deficit (WSD), suggesting that this species was most affected by soil water deficiency. The leaf water content (LWC) correlated negatively with the LDMC and positively with the SLA (narrow leaf blade). Although each plant species belongs to a different strategic group (therophyte, hemicryptophyte and phanerophyte in the juvenile stage), they are all very plastic and therefore suitable for remediation. Despite the unfavourable conditions, selected plant species were able to adapt to poor conditions and form more or less vital populations, which indicate the revegetation as a key measure for remediation of landfill waste from nickel smelter.


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