scholarly journals MICRO-MORPHOLOGY STUDY OF POLLEN GRAINS AND CYPSELA OF SEVEN SELECTED SPECIES, BELONG TO ASTERACEAE FAMILY IN AL-JADRIYA CAMPUS

2019 ◽  
Vol 50 (4) ◽  
Author(s):  
Sadeq & Aliwy
Keyword(s):  
Pollen Grains ◽  
The Other ◽  
Special Importance ◽  
Sonchus Oleraceus ◽  
Lactuca Serriola ◽  
Pollen Surface ◽  
Different Shapes ◽  
Beak Length ◽  
Micro Morphology ◽  
Asteraceae Family

Seven plants species that belong to Asteraceae (Compositae) family have been investigated micro-morphology with the help of scanning electron microscopy (SEM) observations. Plants were collected from University of Baghdad campus during January to May in 2017-2018 and the species are: Calendula persica C. M. May, Carduus pycnocephalus L., Erigeron canadensis L., Lactuca serriola L., Silybum marianum  (L.) Garth, Sonchus oleraceus L., Urospermum picroides (L.) Schmidt. The aim of this study was to describing the external morphology of seeds as well as a detailed study of pollen grains morphology. Special emphasis is given to the size, shape, polar and equatorial length, spines length, length and width of ora and colpi, tectum sclupturing, and the ornamentations on pollen surface, Sonchus oleraceus and Lactuca serriola pollen grains have a special exin sculpture, which is lophate and the other species used in this study is non-lophate, and all the pollen grains of the species used in this study are tri-zono- colporate, Calendula persica is only species that it is exin sculpture is echinate with spines length (3.8-4.3 um), and the exin sculpture of the other species is spinulose. Also special importance is given to the size, shape, pappus, beak length, primary and secondary sculpturing, carpopodium, as well as the surface of the seed (Cypsela), Seeds (cypsela) of the species used in this study were significantly different in morphology, The shapes of the 7 species were differed in each species and it showed 7 different shapes: narrowly-oblong, oblong, long-oblong, board-oblong, widely curved-oblong, narrowly-ellipitic, and narrowly-obovated.

Aspidistra revoluta, a new species from limestone areas in Chongqing, China

Phytotaxa ◽  
2016 ◽  
Vol 257 (3) ◽  
pp. 280 ◽  
Author(s):  
Hao Zhou ◽  
Si-rong Yi ◽  
Qi Gao ◽  
Jie Huang ◽  
Yu-jing Wei
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Average Length ◽  
Chromosome Complement ◽  
Pollen Grains ◽  
The Other ◽  
Morphological Comparison ◽  
Chongqing Municipality ◽  
Karyotype Asymmetry ◽  
A New Species

Aspidistra revoluta (Asparagaceae) is described and illustrated as a new species from limestone areas in southern Chongqing Municipality, China. The new species can be distinguished from the other Aspidistra species by its unique umbrella-like pistil with large revolute stigma lobes that bent downwards and touch the base of the perigone. A detailed morphological comparison among A. revoluta, A. nanchuanensis and A. carnosa is provided. The pollen grains of A. revoluta are subspherical and inaperturate, with verrucous exine. The chromosome number is 2n = 38, and the karyotype is formulated as 2n = 22m + 6sm + 10st. The average length of chromosome complement is 4.50 μm, and the karyotype asymmetry indexes A1 and A2 are respectively 0.37±0.03 and 0.49±0.01.

Interference of Annual Sowthistle (Sonchus oleraceus) in Wheat

Weed Science ◽  
2019 ◽  
pp. 1-21 ◽  
Author(s):  
Sudheesh Manalil ◽  
Hafiz Haider Ali ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Weed Management ◽  
Field Studies ◽  
Integrated Weed Management ◽  
Yield Reduction ◽  
Sonchus Oleraceus ◽  
Poor Seed ◽  
Exponential Decay Model ◽  
Weed Infestation ◽  
Varying Environments ◽  
Asteraceae Family

Abstract Annual sowthistle (Sonchus oleraceus L.) is a broadleaf weed that is increasing in prevalence in the northern cropping regions of Australia. Being a member of Asteraceae family, this weed possesses many biological attributes needed to thrive in varying environments and weed management pressure. Interference of this weed was examined in a wheat (Triticum aestivum L.) crop through field studies in 2016 and 2017. Different densities of S. oleraceus were evaluated for their potential to cause yield loss in wheat: 0.0 (weed free), low (9 to 15 plants m−2), medium (29 to 38 plants m−2), and high (62 to 63 plants m−2). Based on the exponential decay model, 43 and 52 plants m−2 caused a yield reduction of 50% in 2016 and 2017, respectively. Yield components such as panicles m−2 and grains per panicles were affected by weed density. At the high weed infestation level, S. oleraceus produced a maximum of 182,940 and 192,657 seeds m−2 in 2016 and 2017, respectively. Sonchus oleraceus exhibited poor seed retention at harvest as more than 95% of seeds were blown away by wind. Adverse effects on crop, high seed production and wind-blown dispersal may lead to an increased prevalence of this weed in the absence of an integrated weed management strategy utilizing both herbicides and non-chemical options.

scholarly journals Shape Correspondence Analysis for Biomolecules Based on Volumetric Eigenfunctions

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Tao Liao ◽  
Hao-Chih Lee ◽  
Ge Yang ◽  
Yongjie Jessica Zhang
Keyword(s):  
Correspondence Analysis ◽  
Flexible Structures ◽  
Spectral Shape ◽  
The Other ◽  
Shape Deformation ◽  
Second Step ◽  
Analysis Method ◽  
Shape Correspondence ◽  
Dense Point ◽  
Different Shapes

AbstractThe functionality of biomolecules depends on their flexible structures, which can be characterized by their surface shapes. Tracking the deformation and comparing biomolecular shapes are essential in understanding their mechanisms. In this paper, a new spectral shape correspondence analysis method is introduced for biomolecules based on volumetric eigenfunctions. The eigenfunctions are computed from the joint graph of two given shapes, avoiding the sign flipping and confusion in the order of modes. An initial correspondence is built based on the distribution of a shape diameter, which matches similar surface features in different shapes and guides the eigenfunction computation. A two-step scheme is developed to determine the final correspondence. The first step utilizes volumetric eigenfunctions to correct the assignment of boundary nodes that disobeys the main structures. The second step minimizes the distortion induced by deforming one shape to the other. As a result, a dense point correspondence is constructed between the two given shapes, based on which we approximate and predict the shape deformation, as well as quantitatively measure the detailed shape differences.

Pollen morphology of Sabinaria magnifica (Cryosophileae, Coryphoideae, Arecaceae)

Phytotaxa ◽  
2015 ◽  
Vol 207 (1) ◽  
pp. 135 ◽  
Author(s):  
Giovanni Raul Bogota ◽  
Carina Hoorn ◽  
Wim Star ◽  
Rob Langelaan ◽  
Hannah Banks ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
The Other ◽  
Transmission Electron ◽  
Palm Species ◽  
Scanning Electron

Sabinaria magnifica is so far the only known species in the recently discovered tropical palm genus Sabinaria (Arecaceae). Here we present a complete description of the pollen morphology of this palm species based on light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We also made SEM-based comparisons of Sabinaria with other genera within the tribe Cryosophileae. Pollen grains of Sabinaria magnifica resemble the other genera in the heteropolar, slightly asymmetric monads, and the monosulcate and tectate exine with perforate surface. Nevertheless, there are some clear differences with Thrinax, Chelyocarpus and Cryosophila in terms of aperture and exine. S. magnifica differs from its closest relative, Itaya amicorum, in the exine structure. This study shows that a combination of microscope techniques is essential for the identification of different genera within the Cryosophileae and may also be a necessary when working with other palynologically less distinct palm genera. 

scholarly journals Palynology of the Genus Stachytarpheta Vahl. (Verbenaceae)

2010 ◽  
Vol 2 (4) ◽  
pp. 27-33
Author(s):  
Olubukola ADEDEJI
Keyword(s):  
Cluster Analysis ◽  
Grain Size ◽  
Evolutionary History ◽  
Pollen Grains ◽  
Pollen Grain ◽  
The Other ◽  
Pollen Grain Size ◽  
Pollen Diameter ◽  
Stachytarpheta Cayennensis ◽  
Exine Morphology

The exine morphology of pollen grains of Stachytarpheta indica (Linn.) Vahl, Stachytarpheta cayennensis (Rich.) Vahl and Stachytarpheta angustifolia (Mill.) Vahl is reported. This study was carried out with a light microscope. Pollen grains from fresh anthers were collected and aceolysed. Statistical analysis used to analyse the data collected include cluster analysis, correlation analysis, similarity and distance indices. The pollen grains are spheroidal to oblate to sub-oblate in shape. They are aperturate, both colpate and porate. Tricolpate types occur most frequently, acolpate, monocolpate, bicolpate and tetracolpate types less frequently. The multicolpate and multiporate attributes in all the species indicate that the genus is not primitive in evolutionary history and this species probably, evolved around in the same time. According to the size, the pollen grains of the genus falls into groups permagna (pollen diameter 100-200 μm) and giganta (pollen diameter greater than 200 μm). S. cayennensis and S. anguistifolia belong to group permagna and S. indica only in the group giganta. This separates S. indica from the other two species. The large pollen grain size in the genus clearly supports the fact that the flowers in the genus are more insect-and-bird pollinated than wind pollinated. The similarity and distance indices of the species showed that S. cayennensis and S. angustifolia are the closest. S. indica is closer to S. angustifolia but farther from S. cayennensis.

scholarly journals Pollen adaptation to ant pollination: a case study from the Proteaceae

2020 ◽  
Vol 126 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Nicola Delnevo ◽  
Eddie J van Etten ◽  
Nicola Clemente ◽  
Luna Fogu ◽  
Evelina Pavarani ◽  
...  
Keyword(s):  
Seed Set ◽  
Germination Rate ◽  
Pollen Grains ◽  
Relative Effect ◽  
The Other ◽  
Pollen Load ◽  
Pollination Services ◽  
Ant Pollination ◽  
Negative Effect ◽  
Floral Visitors

Abstract Background and Aims Ant–plant associations are widely diverse and distributed throughout the world, leading to antagonistic and/or mutualistic interactions. Ant pollination is a rare mutualistic association and reports of ants as effective pollinators are limited to a few studies. Conospermum (Proteaceae) is an insect-pollinated genus well represented in the south-western Australia biodiversity hotspot, and here we aimed to evaluate the role of ants as pollinators of C. undulatum. Methods Pollen germination after contact with several species of ants and bees was tested for C. undulatum and five co-flowering species for comparison. We then sampled the pollen load of floral visitors of C. undulatum to assess whether ants carried a pollen load sufficient to enable pollination. Lastly, we performed exclusion treatments to assess the relative effect of flying- and non-flying-invertebrate floral visitors on the reproduction of C. undulatum. For this, we measured the seed set under different conditions: ants exclusion, flying-insects exclusion and control. Key Results Pollen of C. undulatum, along with the other Conospermum species, had a germination rate after contact with ants of ~80 % which did not differ from the effect of bees; in contrast, the other plant species tested showed a drop in the germination rate to ~10 % following ant treatments. Although ants were generalist visitors, they carried a pollen load with 68–86 % of suitable grains. Moreover, ants significantly contributed to the seed set of C. undulatum. Conclusions Our study highlights the complexity of ant–flower interactions and suggests that generalizations neglecting the importance of ants as pollinators cannot be made. Conospermum undulatum has evolved pollen with resistance to the negative effect of ant secretions on pollen grains, with ants providing effective pollination services to this threatened species.

scholarly journals SERS activity of hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. D. Ávila-Avilés ◽  
N. Torres-Gómez ◽  
M. A. Camacho-López ◽  
A. R. Vilchis-Nestor
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Pollen Grains ◽  
Precipitation Method ◽  
Chemical Composition Distribution ◽  
Transmission Electron ◽  
Pollen Surface ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Co Precipitation

Abstract Nature provides remarkable examples of mass-produced microscale particles with structures and chemistries optimized by evolution for particular functions. Synthetic chemical tailoring of such sustainable biogenic particles may be used to generate new multifunctional materials. Herein, we report a facile method for the synthesis of hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template. Silver nanoparticles was biosynthesized using pollen grains as a reduction and stabilization agent as well as a bio-template promoting the adhesion of silver nanoparticles to pollen surface. Fe3O4 nanoparticles were synthesized by co-precipitation method from FeSO4. Hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template were obtained and characterized using Scanning Electron Microscopy and Transmission Electron Microscopy to study the morphology and structure; Energy-Dispersive X-ray Spectroscopy to determine the chemical composition distribution; and Confocal Fluorescence Microscopy to demonstrate the fluorescence properties of hybrid nano-microstructures. Furthermore, these hybrid nano-microstructures have been studied by Surface-Enhanced Raman Scattering (SERS), using methylene blue as a target molecule; the hybrid nano-microstructures have shown 14 times signal amplification.

Axial Performance of Various Strengthening Methods Applied on Full-Scale Rectangular RC Columns

2011 ◽  
Vol 82 ◽  
pp. 618-623 ◽  
Author(s):  
Pei Ching Chen ◽  
Min Lang Lin ◽  
Yin Han Wu
Keyword(s):  
Axial Force ◽  
Full Scale ◽  
Reinforcement Ratio ◽  
The Other ◽  
Transverse Reinforcement ◽  
Rc Columns ◽  
Different Shapes ◽  
Adhesive Anchors ◽  
Cfrp Wrapping ◽  
Better Than

The performance of RC columns subjected to axial force is relative to the confinement. CFRP wrapping, a generally adopted retrofit method, was proved not to effectively provide confining force due to the bulging effect on the column face. Therefore, this paper is focused on the performance of the retrofitted full-scale rectangular RC columns using different retrofit schemes including the proposed CFRP wrapping conjugated with CFRP anchors method. A total of eleven rectangular RC columns with low transverse reinforcement ratio were constructed. Among them, one was tested as benchmark; one was purposely constructed with larger transverse reinforcement ratio; five were retrofitted by using CFRP wrapping and CFRP anchors; and the other four were retrofitted by using different shapes of steel jacketing alone or with adhesive anchors. All the specimens were subjected to monotonic incremental axial force until failure occurred. Experimental results demonstrated that the ductility of the specimens retrofitted by using CFRP wrapping with CFRP anchors was significantly improved compared with those retrofitted by using only CFRP wrapping. On the other hand, the specimen with octagonal steel jacketing performed better than all other specimens not only on ductility but also on strength. Finally, a novel numerical model considering the contribution of the retrofit material will be proposed and validated in the future.

Lack of visible post-pollination effects in pollen grains of two Dendrobium cultivars: relationship with pollinia ACC, pollen germination, and pollen tube growth

2008 ◽  
Vol 35 (2) ◽  
pp. 152 ◽  
Author(s):  
Kanjana Luangsuwalai ◽  
Saichol Ketsa ◽  
Apinya Wisutiamonkul ◽  
Wouter G. van Doorn
Keyword(s):  
Pollen Tube ◽  
Ethylene Production ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Flower Colour ◽  
Pollen Grains ◽  
The Other ◽  
Tube Growth ◽  
Colour Changes ◽  
Acc Content

Dendrobium flowers, pollinated with pollinia from individuals of the same cultivar or other cultivars, usually show rapid post-pollination effects such as floral epinasty, a change in flower colour and early perianth senescence. However, pollination with the pollinia of cv. Karen or cv. Kenny flowers did not produce these effects. We compared these two cultivars with cvv. Pompadour, Willie and Sakura, and tested the hypotheses that the differences were related to levels of 1-aminocyclopropane-1-carboxylic acid (ACC) in the pollinia, ethylene production by the pollinated flower, pollen germination, or pollen tube growth. The pollinia of cvv. Karen and Kenny contained as much ACC as the pollinia of cv. Pompadour, but less than the pollinia of cvv. Willie and Sakura. Ethylene production after pollination with cvv. Karen and Kenny pollinia was much lower than after pollination with pollinia from the other cultivars tested. The pollen grains showed normal germination, but cvv. Karen and Kenny pollen grains exhibited much less tube growth than those of the other cultivars. Pollen tube growth in cv. Pompadour was positively affected by ethylene. Ethylene was required and sufficient for the induction of epinasty, rapid perianth colour changes and early perianth senescence, very similar to the changes after pollination. The absence of these effects after pollination with cvv. Kenny and Karen seems to be due to the low ethylene production induced by the pollinia of these cultivars. This low ethylene production could not be accounted for by the ACC content in the pollinia of cvv. Kenny and Karen.

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