scholarly journals Genetic Parameters of Growth Traits and Stem Quality of Silver Birch in a Low-Density Clonal Plantation

Forests ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 52 ◽  
Author(s):  
Pauls Zeltiņš ◽  
Arnis Gailis ◽  
Jānis Jansons ◽  
Juris Katrevičs ◽  
Āris Jansons ◽  
...  
Silva Fennica ◽  
2021 ◽  
Vol 55 (2) ◽  
Author(s):  
Arnis Gailis ◽  
Pauls Zeltiņš ◽  
Roberts Matisons ◽  
Andis Purviņš ◽  
Juris Augustovs ◽  
...  

Populations of tree species with a wide geographic range, such as silver birch ( Roth), show genetic specialization to native environments, while maintaining high phenotypical plasticity. Accordingly, assessment of local specialization is essential for adaptive management. The aim of the study was to detect geographic patterns of local adaptation of growth and stem quality based on two open-pollinated progeny trials in Latvia testing local material. Two provenance regions differing by continentality were distinguished, which also differed in genetic control of growth traits, likely originating from the post-glacial recolonization of vegetation and subsequent natural adaptation. Heritability of the traits was estimated for each of the distinguished regions, indicating differing patterns of genetic adaptation and potential for future selection. Trees from the more continental inland showed superior growth and possessed higher heritability. The coastal provenance region showed slower growth and intermediate heritability of the respective traits. Moderate to high heritability for stem quality traits was estimated irrespectively of region. Overall, better growth and higher heritability suggests that anthropogenic selection within the best inland provenances may constitute better performing and adaptable breeding population compared to the coastal one. Still, overlapping phenotypical variation and heritability of quality traits implies improved stemwood quality for plywood regardless of the provenance region. High adaptive capacity of silver birch genotypes suggests ability to cope with climatic changes, highlighting its potential for climate-smart forestry.Betula pendula


Silva Fennica ◽  
2020 ◽  
Vol 54 (2) ◽  
Author(s):  
Arnis Gailis ◽  
Pauls Zeltiņš ◽  
Andis Purviņš ◽  
Juris Augustovs ◽  
Valts Vīndedzis ◽  
...  

Genetic parameters of growth and stem quality traits were estimated for open-pollinated silver birch Roth progenies in Latvia at the age of 10 and 14 years. Tree height and stem volume were found to be under strong genetic control at both inventories (narrow-sense heritabilities varied from 0.41 to 0.66). Mainly low heritabilities were found for stem defects, yet genetic control of branch diameter, stem straightness and overall stem quality varied from low to high depending on study site. High additive genetic coefficient of variation was found for stem volume (25.3–32.5%). Genetic correlations among growth traits were strong and positive (0.90–0.99). Mainly weak genetic correlations between growth and quality traits implied simultaneous improvement. Still, strong negative correlations between branch angle and stem straightness might result in enlarged knot size for straighter logs. The genetic age-age correlations were strong. Weak genotype by environment interaction and stability of best genotypes over different sites was indicated by strong genetic correlations between trials. Each growth or quality trait alone showed substantial improvement in terms of estimated genetic gain (up to 62% over trial mean for stem volume). Therefore, selection index combining both growth and stem quality may be developed.Betula pendula


Author(s):  
Ashashri Shinde ◽  
Pankaj Gupta ◽  
Sudipt Rath

A quality drug is central to the success of any therapeutic plan. The quality of drug is determined right from the collection to delivery to the patients. The commonest problem involving the medicinal plant stating materials is intentional or unintentional substitution and adulteration owing to multiple reasons like unavailability, higher costs, unfair trade etc. This trend was also present in the olden days, as evident from the concept of substitute drugs (Pratinidhi Dravya) as available in Yogratanakara, Bhavaprakasha and Bhaishajyaratnawali. Therefore, Charka and later Acharyas also have dealt with authentication and standardization of herbal drugs and formulations in detail by using four Pramanas (tools of knowledge) Ch.Vi.8/87. Nowadays the concept of substitution is entirely converted into intentional and unintentional malpractices of adulteration. The established authenticity parameters for plant material identification and standardization like organoleptic, physical, chemical and genetic parameters are relatively inaccessible for routine use. Not withstanding the accuracy and usefulness of these lab parameters and delay in the development of easy to perform parameters for reasonable drug authentication. These adulteration malpractices spoils the market of herbal industries. In this article we discuss about concept of substitution in ancient Ayurveda and at present intentional and unintentional adulteration practices.


Author(s):  
José J. F. Cordeiro Júnior ◽  
Héliton Pandorfi ◽  
José A. D. Barbosa Filho ◽  
Alex S. Moraes ◽  
Luiz A. de Almeida Neto ◽  
...  

ABSTRACT Brazil is the world’s largest producer of sugarcane (Saccharum officinarum L.) and research aimed at propagation has promoted higher quality in production. The objective of this study was to investigate the effect of the variation of micrometeorological elements on the survival and quality of pre-sprouted sugarcane plantlets. The study was carried out in a protected environment (UFRPE). Plantlets of the cultivar RB92579 were obtained by the technique of production of pre-sprouted plantlets. The protected environments were divided into four modules covered with low-density polyethylene plastic + photo-selective shade nets and one module without shade net. Micrometeorological data of global and photosynthetically active solar radiation, air temperature, substrate temperature, relative humidity and the solar radiation spectrum were recorded in each module. The experiment was conducted in a completely randomized design and the principal component analysis was used to verify the association between the cultivation modules, micrometeorological variables and crop variables. Anti-UV low-density polyethylene plastic + freshnet led to lower transmittance of global solar radiation, higher percentage of photosynthetically active radiation and lower plantlet mortality. Substrate temperature above 30.2 °C resulted in higher plantlet mortality. Larger spectrum in the red range led to the production of better quality plantlet. The use of freshnet shade net promoted adequate conditions for the cultivation of sugarcane plantlets and allows obtaining better quality plantlets.


2014 ◽  
Vol 44 (1) ◽  
pp. 27-35 ◽  
Author(s):  
H. Singh ◽  
U. Pannu ◽  
H.K. Narula ◽  
A. Chopra ◽  
V. Naharwara ◽  
...  

2016 ◽  
Vol 65 (1) ◽  
pp. 71-82 ◽  
Author(s):  
M.K. Pagliarini ◽  
W.S. Kieras ◽  
J.P. Moreira ◽  
V.A. Sousa ◽  
J.Y. Shimizu ◽  
...  

AbstractThe study was conducted to estimate the stability, adaptability, productivity and genetic parameters in Slash pine second-generation half-sib families, considering phenotypic traits in early age. Forty-four families from a first generation seed orchard in Colombo-PR, Brazil, were used in this study. Two progenies tests were established in a randomized complete block design. The first test was implemented in March 2009 in Ribeirão Branco, São Paulo state, containing 40 blocks, one tree per plot, 44 treatments (progenies) and 6 controls. Another test was implemented in Ponta Grossa, Paraná state, using the same experimental design and number of plants per plot, and with 24 treatments, 32 blocks. The growth traits evaluated were total height, diameter at breast height (dbh) and wood volume, within five years. The form traits evaluated were stem form, branch thickness, branch angle, number of branches, fork and fox tail five years after planting. Deviance analysis and estimates of stability, adaptability, productivity and genetic parameters were performed using the methods of best linear unbiased predictor (BLUP) and residual maximum likelihood (REML). There was significant variation among progenies for growth and form traits. Considerable genetic variation was detected mainly for wood volume. High coefficients of genetic variation and heritability showed low environmental influence on phenotypic variation, which is important for the prediction of genetic gain by selection. Crosses between different progenies individuals groups will be prioritized for obtaining heterotics genotypes and increase the probability of obtaining high specific combining ability.


2010 ◽  
Vol 43 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Frank Fleischer ◽  
Thomas Weber ◽  
Sofia Deloudi ◽  
Lukáš Palatinus ◽  
Walter Steurer

Comprehensive tests on the density-modification methods charge flipping [Oszlányi & Sütő (2004).Acta Cryst.A60, 134–141] and low-density elimination [Shiono & Woolfson (1992).Acta Cryst.A48, 451–456] for solving crystal structures are performed on simulated diffraction data of periodic structures and quasicrystals. A novel model-independent figure of merit, which characterizes the reliability of the retrieved phase of each reflection, is introduced and tested. The results of the performance tests show that the quality of the phase retrieval highly depends on the presence or absence of an inversion center and on the algorithm used for solving the structure. Charge flipping has a higher success rate for solving structures, while low-density elimination leads to a higher accuracy in phase retrieval. The best results can be obtained by combining the two methods,i.e.by solving a structure with charge flipping followed by a few cycles of low-density elimination. It is shown that these additional cycles dramatically improve the phases not only of the weak reflections but also of the strong ones. The results can be improved further by averaging the results of several runs and by applying a correction term that compensates for a reduction of the structure-factor amplitudes by averaging of inconsistently observed reflections. It is further shown that in most cases the retrieved phases converge to the best solution obtainable with a given method.


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