scholarly journals Genetic and no genetic variability of two-year old seedlings of 13 hybrid plane half-sib lines

2005 ◽  
pp. 69-85 ◽  
Author(s):  
Radmila Knezevic ◽  
Mirjana Sijacic-Nikolic

This paper presents the results of the analysis of variability of 8 analyzed morph metric parameters in two-year old seedlings of 13 half-sib lines at different levels. The recorded genetic and no genetic variability is conditioned by numerous different factors. The important causes of genetic variability are: partial incompatibility of parent trees, partial hybrid sterility, predominant inbreeding, frequent mutations with the growth of parent trees, very abundant gene recombination's, etc. The causes of no genetic seedling variability are: external environmental conditions (soil humidity, conditions of cultivation, sylvotechnical interventions, etc) and the internal or the somatic environment of seedling.

ACTA IMEKO ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 86 ◽  
Author(s):  
Mariella Diaferio ◽  
Dora Foti ◽  
Nicola Ivan Giannoccaro ◽  
Salvador Ivorra Ivorra

This paper presents the dynamic experimental campaign carried out on a stocky masonry clock tower situated in the Swabian Castle of Trani (Italy). The main objective of this paper is, after estimating the main frequencies and vibration modes of the considered structure, defining the transmission of vibrations along the height of the tower by varying the forced frequency at the base. At this aim, short acceleration records have been acquired simultaneously in 20 points of the tower at different levels, due to a series of sinusoidal forced vibrations applied at the base by using a pneumatic shaker device specify designed for the tests. The proposed procedure permit to extract for each monitored point the amplitude of the sinusoidal component related to the excitation frequency and the phase shift due to the structure damping. The results of the proposed procedure are compared with the results of a classical operational modal analysis in environmental conditions in order to demonstrate that the short forced tests permit to classify the typology of the structure mode shapes.


Genetika ◽  
2012 ◽  
Vol 44 (3) ◽  
pp. 499-512 ◽  
Author(s):  
Novo Przulj ◽  
Vojislava Momcilovic

Environmental conditions in the Pannonian zone can be characterized with moderate high temperature and partially water deficit during grain filling of spring barley, although low temperature and water deficit are possible also in period till anthesis. This study was conducted to evaluate the variation of the duration of the period from emergence to anthesis (VP), duration of grain filling period (GFP), plant height (PH), spikes number m-2 (SN), grains number spike-1 (GN), thousand grains weight (GW) and yield (YIL) in spring two-rowed barley in conditions of the Pannonian zone. All three factors; genotype, environment and the interaction GxY affected the studied traits. Average VP was 777 GDD, GFP 782 GDD, PH 78 cm, SN 523, GN 28.2, GW 43.2 g and YIL 6.26 t ha-1. Variation across varieties was higher than across growing seasons. Heritability varied from 0.66 for YIL to 0.94 for VP and GFP. This study confirmed that a sufficiently large genetic variability must be base for selecting appropriate varieties for the Pannonian zone conditions. In order to determine high yielding and quality barley extensive research in relation to breeding, variety choice for production and growing practice must be done.


1974 ◽  
Vol 23 (S1) ◽  
pp. 145-156
Author(s):  
M. Milani Comparetti ◽  
D.P. Pace ◽  
F. Britti ◽  
D. Casini

All living beings are variously conditioned by both continuous and repetitive chronological phenomena.The greater biochemical complexity afforded by the genome of higher organisms contributes to increase their independence from environmental chronological phenomena (= increased homeostasis). Genetic variability (originated by mutations and required for evolutionary adaptation) extends its influence on the biochemical mechanisms of homeostasis.Phenotypical variability, if prevailing environmental conditions are constant, is based on genotypical variability. Thus the variability observed in the duration of homeostatic mechanisms must be genotypical.In current chronogenetical theory, Gedda and Brenci's concept of the Ergon) Chronon System provides the explanation for the observed variability in the duration of homeostatic phenomena; in this concept, the differential stability of genie information explains the variation of patterns of senescence in different individuals. From the viewpoint of the continuity of life, senescence must be considered as “physiological”, but its individual, especially initial degenerative manifestations are generally considered as pathological. The fundamental applications of chronogenetics to the human species are to be aimed in this direction.Individual phenomena of senescence may be more or less linear; the pattern of the respective curves may be common to the entire species, or else it may afford varying degrees of variability. The ascertainment of the respective curves (for which some indicators may serve as examples) is a prerequisite for the application of chronogenetics to the individual, framing him within his genealogy and providing great potential developments for preventive medicine.


2011 ◽  
Vol 41 (No. 1) ◽  
pp. 11-16 ◽  
Author(s):  
L. Bettaieb-Ben Kaab ◽  
M. El Felah ◽  
M. Lauriere

Two Tunisian barley varieties, Martin and Rihane, differing by their degrees of adaptation to the environmental conditions and grain yield potential, were grown under different levels of nitrogen (N) fertilisation. The effect of nitrogen supply on the hordein components (expressed in mg per albumen) was determined by Nu-PAGE electrophoresis system using the MOBS running buffer and densitometric analysis. Increasing nitrogen fertilisation increased the protein content by increasing the amount of C-hordeins. The sub-fraction BIII of high molecular weight B-hordeins appeared, in the present study, as the best criterion for distinguishing between the two barley varieties genetic adaptation, and its quantification could be recommended for the understanding of the quality properties of the barley response to different environmental conditions particularly nitrogen fertilisation which appears to be the main origin of differences in the protein aggregation mode of different B-hordein sulphur-rich sub-fractions.    


1954 ◽  
Vol 1954 ◽  
pp. 83-85 ◽  
Author(s):  
I. L. Mason

There are two schools of thought concerning the most appropriate environment in which to select breeding animals. One says ‘ Always select animals under environmental conditions similar to those where they are to be used ‘. The other says ‘ Select breeding animals in the optimum environment so that they have the best chance of revealing their genetic capabilities ‘. Experiments on growth of laboratory mice and experience with European cattle in the tropics have shown the advisability of the first course in these cases. In regard to hill sheep and dairy cattle in Britain, on the other hand, practice favours the second course, but there is little experimental evidence to support it.


2012 ◽  
Vol 57 (1) ◽  
pp. 89-99 ◽  
Author(s):  
H. STORM ◽  
R. STØEN ◽  
P. KLEPSTAD ◽  
F. SKORPEN ◽  
E. QVIGSTAD ◽  
...  

2015 ◽  
Vol 20 (6) ◽  
pp. 813-835 ◽  
Author(s):  
Laura Policardo

AbstractIf the demand for environmental goods is increasing with income, democratization shifts the decisive power from a rich autocrat to a poorer individual (decisive voter), so it should be associated with worse environmental conditions. In this paper, it is shown through a theoretical model that: (i) democratization may have mixed effects on the level of environmental quality, depending on the size of the price and income effects on the demand for environmental quality associated with a decrease in the decisive political actor's wealth; and (ii) assuming that society is composed of two classes of individuals with different levels of exposure to pollution, and assuming moreover that the decisive voter belongs to the most exposed class of individuals while the autocrat does not, democratization is beneficial for the environment, and the better the effect on the environment, the bigger the difference in wealth between the two decisive political actors.


2021 ◽  
Vol 87 (1) ◽  
pp. 57-67
Author(s):  
Celina Luízar Obregón ◽  
Daniel L’hermite

In this work, laser-induced plasma spectroscopy was used to identify the elemental composition, at different depths, of a commercial Peruvian ceramic. The IVEA MobiLIBS system and IUMTEK TX1000 system were used, under environmental conditions and 5.6 mJ of energy, forming craters of approximately 60 μm in diameter. To improve accuracy, repetitions of the impact points were performed, accumulating the signals at the same depth. The blue and white pigments that covered it, as well as the matrix paste, were characterized, making different levels of penetration in the material, obtaining their respective elemental composition. This allowed finding the difference between stratigraphic layers, based mainly on the variation of the intensities of Copper, Titanium, Carbon and other characteristic elements of the clays that make up the matrix paste. Contemporary pottery was found to have sequential layers of decoration, engobe and matrix paste.


2021 ◽  
Vol 73 (4) ◽  
pp. 868-876
Author(s):  
H.C. Viana ◽  
W.B. Jesus ◽  
S.K.L. Silva ◽  
M.B. Jorge ◽  
D.M.S. Santos ◽  
...  

ABSTRACT The melanomacrophage centers (MMCs) in the liver of fish are indicators of environmental conditions, as they are involved in xenobiotic biotransformation. The objective of this study was to evaluate the number of MMC in the liver of juveniles and adults of Sciades herzbergii from areas with different levels of contamination. The fish were caught at three points (reference - A1, potentially impacted - A2 and contaminated - A3), in São José bay (Maranhão, Brazil), in four samples. The livers were subjected to the standard histological procedure and 5μm sections were stained with hematoxylin-eosin. In livers of A2 adult individuals (260.50±161.50 MMCs / mm²) they presented a greater number of MMCs when compared to A3 adults (60.00 ± 30.10 MMCs / mm²). Juveniles showed considerable values in A1 (100.00 ± 0.00 MMCs/mm²) and A2 (95.33 ± 33.00 MMCs / mm²) compared to juveniles in A3 (49.00±0.00 MMCs/mm²). These high values are unexpected for young people. The average number of MMC correlated with the rainy season in the region. The use of hepatic MMCs as a biomarker of exposure to pollutants, in particular substances from fisheries systems, such as ammonia and nitrite, proved to be adequate to differentiate areas with different levels of impacts.


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