scholarly journals Response of Polygonatum Multiflorum and P. Odoratum morphological Characteristics and Population Structure to Variation in Environmental Factors

Botanica ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 111-120
Author(s):  
Birutė Karpavičienė ◽  
Giedrė Elzbieta Mlečkaitė
Keyword(s):  
Population Structure ◽  
Life Stage ◽  
Light Availability ◽  
Morphological Characteristics ◽  
Canopy Cover ◽  
Shoot Density ◽  
Crucial Effect ◽  
Shrub Canopy ◽  
The Mean ◽  
Total Tree

AbstractThe morphological variation and population structure were studied in seven populations of Polygonatum multiflorum and 19 populations of P. odoratum. The mean number of flowers per shoot and per inflorescence as well as inflorescence number per shoot in both species correlated negatively with total tree and shrub canopy cover, while the mean number of flowers per inflorescence in P. odoratum correlated positively with the soil pH. The shoot density and life stage composition in P. odoratum populations depended on total tree and shrub canopy cover, which negatively correlated with the density of generative shoots in populations of both species. The results of this study revealed the crucial effect of light availability expressed via total tree and shrub canopy cover in the habitats of Polygonatum species to their flowering intensity and population structure.

scholarly journals Population structure of Chinese southwest wheat germplasms resistant to stripe rust and powdery mildew using the DArT-seq technique

2018 ◽  
Vol 48 (4) ◽  
Author(s):  
Tianqing Chen ◽  
Piyada Alisha Tantasawat ◽  
Wei Wang ◽  
Xu Gao ◽  
Liyi Zhang
Keyword(s):  
Population Structure ◽  
Disease Resistance ◽  
Polymorphic Information Content ◽  
Wheat Breeding ◽  
Wheat Varieties ◽  
Group I ◽  
Population Structure Analysis ◽  
Specific Allele ◽  
The Mean ◽  
Different Origins

ABSTRACT: Understanding genetic variability in existing wheat accessions is critical for collection, conservation and use of wheat germplasms. In this study, 138 Chinese southwest wheat accessions were investigated by genotyping using two resistance gene makers (Pm21 and Yr26) and DArT-seq technique. Finally, about 50% cultivars (lines) amplified the specific allele for the Yr26 gene (Gwm11) and 40.6% for the Pm21 gene (SCAR1265). By DArT-seq analysis, 30,485 markers (6486 SNPs and 23999 DArTs) were obtained with mean polymorphic information content (PIC) value 0.33 and 0.28 for DArT and SNP marker, respectively. The mean Dice genetic similarity coefficient (GS) was 0.72. Two consistent groups of wheat varieties were identified using principal coordinate analysis (PCoA) at the level of both the chromosome 6AS and the whole-genome, respectively. Group I was composed of non-6VS/6AL translocation lines of different origins, while Group II was composed of 6VS/6AL translocation (T6VS/6AL) lines, most of which carried the Yr26 and Pm21 genes and originated from Guizhou. Besides, a model-based population structure analysis revealed extensive admixture and further divided these wheat accessions into six subgroups (SG1, SG2, SG3, SG4, SG5 and SG6), based on their origin, pedigree or disease resistance. This information is useful for wheat breeding in southwestern China and association mapping for disease resistance using these wheat germplasms in future.

scholarly journals Selection, Load and Inbreeding Depression in a Large Metapopulation

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1191-1202 ◽  
Author(s):  
Michael C Whitlock
Keyword(s):  
Population Structure ◽  
Inbreeding Depression ◽  
Population Subdivision ◽  
Response To Selection ◽  
Mutation Load ◽  
Deleterious Alleles ◽  
Subdivided Population ◽  
Soft Selection ◽  
Mean Fitness ◽  
The Mean

Abstract The subdivision of a species into local populations causes its response to selection to change, even if selection is uniform across space. Population structure increases the frequency of homozygotes and therefore makes selection on homozygous effects more effective. However, population subdivision can increase the probability of competition among relatives, which may reduce the efficacy of selection. As a result, the response to selection can be either increased or decreased in a subdivided population relative to an undivided one, depending on the dominance coefficient FST and whether selection is hard or soft. Realistic levels of population structure tend to reduce the mean frequency of deleterious alleles. The mutation load tends to be decreased in a subdivided population for recessive alleles, as does the expected inbreeding depression. The magnitude of the effects of population subdivision tends to be greatest in species with hard selection rather than soft selection. Population structure can play an important role in determining the mean fitness of populations at equilibrium between mutation and selection.

Carbon Stocks of Linear Category of Trees Out Side Forest in Anantapuramu District, Andhra Pradesh, India

2016 ◽  
Vol 39 (4) ◽  
pp. 303-308
Author(s):  
G. Kavitha ◽  
S. Salamma ◽  
M. Ramesh ◽  
Mudavath Naik ◽  
M. Kumar ◽  
...  
Keyword(s):  
Basal Area ◽  
Carbon Stocks ◽  
Linear Structures ◽  
Carbon Sequestration Potential ◽  
Sequestration Potential ◽  
The Mean ◽  
Angiosperm Species ◽  
Linear Category ◽  
Total Tree ◽  
Trees Outside Forest

In the present study, carbon stocks of linear structures of trees outside forest in Anantapuramu district was estimated through sampling of 344 (0.1 ha) plots. A total of 4229 tree individuals belonging to 66 angiosperm species were enumerated in the sampled plots. The mean tree density is 122.8per ha; mean diameter at breast height 4.04 m; mean basal area 15.43 m2 ha-1.Mean volume of trees with >10 cm diameter is 15.50 m3 ha-1; mean total tree biomass is 120.81 tons ha-1.The mean carbon stock is 57.385 tons ha-1 and extrapolated biomass and carbon content for linear structures are 0.176 Mt and 0.083 Mt respectively. The carbon sequestration potential of trees outside forests of Anantapuramu district is estimated at 0.304 Mt.

scholarly journals Structure and dynamics of a Cariniana estrellensis (Lecythidaceae) population in a fragment of Atlantic Forest in Minas Gerais, Brazil

Rodriguésia ◽  
2012 ◽  
Vol 63 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Yule Roberta Ferreira Nunes ◽  
Miguel Petrere Jr.
Keyword(s):  
Population Structure ◽  
Seed Production ◽  
Size Structure ◽  
Canopy Cover ◽  
High Rate ◽  
Structure And Dynamics ◽  
Seedling Bank ◽  
Phase Size ◽  
Population Structure And Dynamics ◽  
Establishment Phase

We aimed to describe population structure and dynamics of Cariniana estrellensis (Raddi) Kuntze to test the hypothesis that this species survives in the forest by forming a seedling bank. We evaluated seed germination, spatial distribution, and recruitment, growth and mortality rates of young individuals. To characterize population structure a 1.2-ha plot was defined, where reproductive adults were mapped; also 100 6 m² sub-plots were established to characterize structure and monitor dynamics of young individuals. We estimated seed production using seed collectors and determined the percentage of canopy cover by hemispherical photographs. Seed rain and saplings showed clustered distribution indicating habitat-patch formation. Sapling mortality occurred mainly during the initial establishment phase. Size structure was characterized by many saplings (X = 9,763 individuals ha-1) and few adults (X = 5 individuals ha-1), associated with a high rate of seed production (X = 60,800 seeds ha-1), low growth rates (X = 2.37 cm ano-1) and mortality (15.66%) of established saplings, showing that species invest in seedling bank formation as a reproductive strategy.

Development of comandra blister rust on lodgepole pine

1990 ◽  
Vol 20 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Brian W. Geils ◽  
William R. Jacobi
Keyword(s):  
Lodgepole Pine ◽  
Tree Height ◽  
Infection Site ◽  
Canker Disease ◽  
Susceptibility To Infection ◽  
Blister Rust ◽  
The Mean ◽  
Central Rocky Mountains ◽  
Stem Cankers ◽  
Total Tree

The comandra blister rust parasite (Cronartiumcomandrae Pk.) causes a serious canker disease of lodgepole pine (Pinuscontorta Dougl. ex Loud. ssp. latifolia (Engelm.) Critch.) in the central Rocky Mountains. The expansion, longevity, and distribution of comandra blister rust cankers were studied by annual monitoring, reconstructing canker histories, and random sampling. In saplings, infections occur throughout the lower 80% of the crown; and branch cankers expand toward the bole at 2.5 cm•year−1, regardless of temperature, age, position, tree size, vigor, or susceptibility to infection. The proportion of branch cankers that develop into stem cankers decreases logistically both with distance from infection site to bole and with time since infection. Fewer than 50% of branch cankers that are farther than 20 cm from the bole or more than 8 years old are expected to establish stem cankers. The proportion of branch cankers that become stem cankers decreases with distance more rapidly for comandra blister rust than for other stem rusts. The mean height of stem cankers increases with total tree height, but cankers are uncommon at the top of the crown and low on the trunk of larger trees. The number of years for a canker to girdle its host equals the diameter of the stem at the center of the canker measured in centimetres. Because girdling cankers develop infrequently, slowly, and predictably, potential losses from comandra blister rust can be reduced by timely and appropriate removal of damaged trees.

LA MESURE DE L’INTERFÉRENCE DU CHIENDENT DANS L’ORGE

1982 ◽  
Vol 62 (1) ◽  
pp. 183-188 ◽  
Author(s):  
R. RIOUX
Keyword(s):  
Regression Analysis ◽  
Hordeum Vulgare ◽  
Linear Relationship ◽  
Linear Relation ◽  
Shoot Density ◽  
Yield Variability ◽  
Hordeum Vulgare L ◽  
The Mean ◽  
The Relationship ◽  
Agropyron Repens

Barley (Hordeum vulgare L. ’Champlain’) was grown with quackgrass (Agropyron repens (L.) Beauv.) at various densities for 3 yr. According to the regression analysis, a linear relation is appropriate to describe the relationship between yield of barley and biomass or density of quackgrass. A greater proportion of yield variability was explained by density (64%) than by biomass (40%). Density is then a better criterion than biomass to predict yield lost in barley. The linear relationship between barley yield and the shoot density of quackgrass is estimated by the following equation: yield barley = 345.3–0.5682 dens, quackgrass. An increase of 10 shoots/m2 in the mean density of quackgrass resulted in a mean loss of 6 g/m2 in the yield of barley.

VARIATION IN ANAL FIN RAY COUNT OF THE REDSIDE SHINER RICHARDSONIUS BALTEATUS (RICHARDSON)

1953 ◽  
Vol 31 (3) ◽  
pp. 211-225 ◽  
Author(s):  
C. C. Lindsey
Keyword(s):  
Morphological Characteristics ◽  
Introduced Populations ◽  
Fin Ray ◽  
Parent Stock ◽  
Different Populations ◽  
The Mean ◽  
Redside Shiner ◽  
Richardsonius Balteatus ◽  
Bodies Of Water ◽  
Different Parts

Anal fin rays were counted on 4766 specimens of Richardsonius balteatus from 61 localities in British Columbia. Individual counts varied from 10 to 21, and mean counts of different populations varied from 12.06 to 17.51. Significant differences in counts occurred between different bodies of water, between recently introduced populations and their parent stock, between different parts of the same lake, and between different year classes. Ray counts tended to be higher amongst females in populations with high over-all means, and higher amongst males in populations with low over-all means. A positive correlation was demonstrated between water temperatures recorded in the vicinity of developing fry and the mean numbers of anal rays produced. Within each latitudinal zone a similar correlation occurred between mean ray count and average air temperature during the spawning season, but data on 109 means of populations in U.S.A. and Canada indicated a tendency, probably genetic, towards production, at equivalent temperature, of higher ray count towards the northern end of the range. Loose correlations between anal ray count and certain other morphological characteristics suggest that these may be dependent on more or less common environmental factors but are not linked by direct causality.

scholarly journals HDPE/SILICA COMPOSITES- PART I: PREPARATION AND CHARACTERIZATION OF METHYLSILANE AND OCTYLSILANE-MODIFIED SILICAS

2019 ◽  
Vol 16 (32) ◽  
pp. 263-278
Author(s):  
Vanessa Machado Babinski RAMOS ◽  
Maurício Gammertt RÖHNELT ◽  
Rodrigo BRAMBILLA
Keyword(s):  
Silica Gel ◽  
Morphological Characteristics ◽  
Specific Area ◽  
Sem Images ◽  
Adsorption Sites ◽  
Pyrogenic Silica ◽  
The Mean ◽  
Complementary Techniques ◽  
Adsorption Desorption

This paper reports the main results concerning the synthesis and characterization of methylsilane and octylsilane-modified silicas. The modification of the silicas with these groups aims to make the silica surface hydrophobic and thus compatible with high-density polyethylene (HDPE) in HDPE/silica composites. In the present work, two types of silica were organofunctionalized: a pyrogenic silica and a silica gel. The silicas were characterized by a series of complementary techniques with the objective of investigating the nature of the surface species and their textural and morphological characteristics. The SEM images showed that the modification of the silicas with organosilanes has been not resulted in changes on the morphology and on the size of silica particles. In relation to the texture properties, determined by N2 adsorption-desorption porosimetry, the silica modification resulted in a decrease of the specific area (SBET) and the mean pore volume, a behavior attributed to the partial coverage of the adsorption sites by the organosilane molecules. The TGA analysis showed that both the methylsilane groups and the octylsilane groups on the surface of silica and silica gel are thermally stable up to 200 ° C, which enables the organofunctionalized silicas in terms of thermal stability, for the process of preparing the composites by extrusion. The results of applying these organofunctionalized silicas in the development of HDPE/silica composites will be presented in a subsequent article, part II of this research.

scholarly journals Embryo Morphokinetic Parameters Evaluated Using a Time-Lapse Embryo Monitoring System Can Predict the Embryo Developmental Potential in ICSI Cycles

2021 ◽  
Author(s):  
Qina He ◽  
Guidong Yao ◽  
Jiahuan He ◽  
Guang Yang ◽  
Ziwen Xu ◽  
...  
Keyword(s):  
Monitoring System ◽  
Embryo Quality ◽  
Morphological Characteristics ◽  
Time Lapse ◽  
Reproductive Technologies ◽  
Embryo Morphology ◽  
High Quality ◽  
Developmental Potential ◽  
Morphokinetic Parameters ◽  
The Mean

Abstract At present, embryo morphology assessment based on the observation of the embryonic morphological characteristics at several specific time points has been mainly used for selecting the high-quality embryo. However, we all know that embryo development is a dynamic process. Many research results on the correlation between the embryo morphokinetic parameters and embryo quality and development potential were inconsistent. With the help of time-lapse imaging, the development processes and outcomes of a total of 365 embryos were cultured and analyzed in this study. The results showed that the mean tPNf and t2 of the high-quality embryo were significantly shorter than the low-quality embryo; the mean t2PBe and tPNa of the high-quality embryo from the implantation group were significantly shorter than those from the non-implantation group. In addition, based on the quartile grouping of each morphokinetic parameter, the embryos that had 21.15≤tPNf≤25.30 value were significantly higher in embryo quality when compared with the embryos that had the tPNf values outside the range on Days 3. Similarly, the embryos that had values of t2≤25.60 were significantly higher in embryo quality than those with outside the range values on Days 3. Thus, we demonstrated that the morphokinetic parameter evaluated using a time-lapse embryo monitoring system can predict the embryo quality, and be benefit for the selection of the high-quality embryos and improvement for the implantation success of the patient in assisted reproductive technologies.

scholarly journals INVESTIGATION ON PRE-TREATMENT PROCESS IN MICROCRYSTALLINE CELLULOSE (MCC) FROM OIL PALM EMPTY FRUIT BUNCH (EFB)

2018 ◽  
Vol 3 (1) ◽  
pp. 87-96
Author(s):  
Muhammad Arif Fahmi Supian ◽  
Khairatun Najwa Mohd Amin ◽  
Saidatul Shima Jamari ◽  
Shahril Mohamad
Keyword(s):  
Microcrystalline Cellulose ◽  
Morphological Characteristics ◽  
Alkaline Treatment ◽  
Empty Fruit Bunch ◽  
Characteristic Peak ◽  
Reinforcing Agent ◽  
Good Potential ◽  
The Mean ◽  
The Difference ◽  
Pre Treatment

In this study, microcrystalline cellulose (MCC) was extracted from empty fruit bunch (EFB) with alkaline treatment, bleaching and acid hydrolysis treatment and its properties were compared with commercial MCC. Two conditions were optimized in this study which are fiber consistency and sodium hydroxide (NaOH) concentration in alkaline pretreatment. The obtained optimum consistency and alkaline concentration are 5% and 20%respectively. The physicochemical and morphological characteristics, elemental composition and size distribution of the obtained alpha cellulose and MCC were analyzed in this work. Fourier transform infrared spectroscopy (FTIR) analysis provided clear evidence that the characteristic peak of lignin and hemicellulose were absent in the spectrum of the alpha cellulose and MCC. The difference in surface morphology and aggregation between alpha cellulose, MCC and commercialized MCC were observed by scanning electron microscopy (SEM). The mean length of approximately 251.3 μm, 41.4 μm and 138.6 μm were measured for alpha cellulose, MCC and commercialized MCC respectively. Thus, the isolated MCC from EFB has a good potential to be utilized as reinforcing agent in green composites and may be a precursor for future roselle derived nanocellulose, and thus a promising subject in nanocomposite research.

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