Assessing and overcoming genetic trade-offs in breeding grazing-tolerant lucerne

2017 ◽  
Vol 68 (11) ◽  
pp. 952
Author(s):  
L. Pecetti ◽  
P. Annicchiarico
Keyword(s):  
Genetic Variation ◽  
Cold Season ◽  
Grazing Management ◽  
Physiological Traits ◽  
Mild Winter ◽  
Trade Offs ◽  
Plant Persistence ◽  
Plant Habit ◽  
Genotype Evaluation ◽  
Selection Of

Selection of grazing-tolerant lucerne (Medicago sativa L.) for mild-winter environments is challenged by marked cold-season dormancy and prostrate habit often observed in tolerant material. This study aimed to assess the amount of genetic variation and genetically based trade-offs for key traits in four biparental populations, and their implications for selection. Some 432 cloned F1 progenies from four crosses between contrasting genotypes (erect, not very dormant, non-grazing tolerant v. prostrate, dormant, tolerant) were evaluated for dry matter (DM) yield and final plant persistence under continuous, intense sheep grazing for 3 years, along with a set of morpho-physiological traits. Both DM yield and persistence displayed negative genetic correlation with erect plant habit (rg –0.31 to –0.87, depending on the cross), with persistence inversely related also to cold-season growth (rg –0.33 to –0.73). Correlations of performance traits with DM yield before grazing management, plant diameter and leaflet area were inconsistent or nil. DM yield during grazing management and persistence exhibited large genetic variation (CVg 33.3–57.8%), and within-cross variance largely exceeded between-cross variance. Morpho-physiological traits had lower genetic variation and even greater relative within-cross variance than yield and persistence. Selection for grazing-tolerant germplasm could exploit large genetic variation, but it requires extensive within-cross genotype evaluation to produce material with little dormancy and relatively erect growth habit.

Plasticity and trade-offs in physiological traits of intertidal mussels subjected to freshwater-induced environmental variation

2016 ◽  
Vol 553 ◽  
pp. 93-109 ◽  
Author(s):  
L Ramajo ◽  
L Prado ◽  
AB Rodriguez-Navarro ◽  
MA Lardies ◽  
CM Duarte ◽  
...  
Keyword(s):  
Environmental Variation ◽  
Physiological Traits ◽  
Trade Offs

scholarly journals Agro-Morphological Characterization and Assessment of Variability in Aromatic Rice Germplasm

2012 ◽  
Vol 37 (1) ◽  
pp. 1-8 ◽  
Author(s):  
M Parikh ◽  
NK Motiramani ◽  
NK Rastogi ◽  
B Sharma
Keyword(s):  
Genetic Parameters ◽  
Agronomic Traits ◽  
Morphological Characterization ◽  
Aromatic Rice ◽  
Spikelet Sterility ◽  
Plant Parts ◽  
Rice Germplasm ◽  
Spikelets Per Panicle ◽  
Plant Habit ◽  
Selection Of

The present studies were carried out to characterize seventy-one aromatic rice germplasm from IGKV, Raipur. These germplasm were characterized and grouped on the basis of anthocyanin pigmentation, plant habit, and awning character. On the basis of pigmentation distribution in 10 plant parts, a total of twelve groups were formed with group one having no pigmentation and group twelve with pigmentation in 9 plant parts. On the basis of plant habit and awning character, three groups of each were formed. The genetic parameters for the ten agronomic traits indicated that the selection of genotypes may be done for fertile spikelets per panicle, spikelet density, spikelet sterility percentage, and hundred seed weight. Thus, on the basis of above characters, the genotypes Tulsi Mala, Baanspati, Ganga Balu, Samund Chini, Tulsi Amrit, Dudh Dhan, Kari Gilas, Shankar Jeera, and Jata Shankar may be selected for future study. DOI: http://dx.doi.org/10.3329/bjar.v37i1.11168 Bangladesh J. Agril. Res. 37(1): 1-8, March 2012

scholarly journals Genetic variation in the dietary sucrose modulation of enzyme activities in Drosophila melanogaster

1984 ◽  
Vol 43 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Billy W. Geer ◽  
Cathy C. Laurie-Ahlberg
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Enzyme Activities ◽  
Glycogen Synthesis ◽  
Krebs Cycle ◽  
Natural Populations ◽  
Substitution Lines ◽  
Chromosome Substitution Lines ◽  
High Sucrose Diet ◽  
Selection Of

SUMMARYGenetic variation in the modulating effect of dietary sucrose was assessed in Drosophila melanogaster by examining 27 chromosome substitution lines coisogenic for the X and second chromosomes and possessing different third isogenic chromosomes derived from natural populations. An increase in the concentration of sucrose from 0·1% to 5% in modified Sang's medium C significantly altered the activities of 11 of 15 enzyme activities in third instar larvae, indicating that dietary sucrose modulates many, but not all, of the enzymes of D. melanogaster. A high sucrose diet promoted high activities of enzymes associated with lipid and glycogen synthesis and low activities of enzymes of the glycolytic and Krebs cycle pathways, reflecting the physiological requirements of the animal. Analyses of variance revealed significant genetic variation in the degrees to which sucrose modulated several enzyme activities. Analysis of correlations revealed some relationships between enzymes in the genetic effects on the modulation process. These observations suggest that adaptive evolutionary change may depend in part on the selection of enzyme activity modifiers that are distributed throughout the genome.

Addressing pose estimation issues for machine vision based UAV autonomous serial refuelling

2007 ◽  
Vol 111 (1120) ◽  
pp. 389-396 ◽  
Author(s):  
G. Campa ◽  
M. R. Napolitano ◽  
M. Perhinschi ◽  
M. L. Fravolini ◽  
L. Pollini ◽  
...  
Keyword(s):  
Machine Vision ◽  
Pose Estimation ◽  
Estimation Algorithm ◽  
Computational Effort ◽  
Unmanned Aircraft ◽  
Light Sources ◽  
Estimation Algorithms ◽  
Trade Offs ◽  
Labeling Algorithms ◽  
Selection Of

Abstract This paper describes the results of an effort on the analysis of the performance of specific ‘pose estimation’ algorithms within a Machine Vision-based approach for the problem of aerial refuelling for unmanned aerial vehicles. The approach assumes the availability of a camera on the unmanned aircraft for acquiring images of the refuelling tanker; also, it assumes that a number of active or passive light sources – the ‘markers’ – are installed at specific known locations on the tanker. A sequence of machine vision algorithms on the on-board computer of the unmanned aircraft is tasked with the processing of the images of the tanker. Specifically, detection and labeling algorithms are used to detect and identify the markers and a ‘pose estimation’ algorithm is used to estimate the relative position and orientation between the two aircraft. Detailed closed-loop simulation studies have been performed to compare the performance of two ‘pose estimation’ algorithms within a simulation environment that was specifically developed for the study of aerial refuelling problems. Special emphasis is placed on the analysis of the required computational effort as well as on the accuracy and the error propagation characteristics of the two methods. The general trade offs involved in the selection of the pose estimation algorithm are discussed. Finally, simulation results are presented and analysed.

A Spectral Optimization Algorithm for Multi-Objective Prototype Selection

1995 ◽  
Author(s):  
Andy Dong ◽  
Alice M. Agogino
Keyword(s):  
Optimization Algorithm ◽  
Parametric Design ◽  
Selection Process ◽  
Objective Evaluation ◽  
Design Synthesis ◽  
Multi Objective ◽  
Trade Offs ◽  
Spectral Optimization ◽  
The Right ◽  
Selection Of

Abstract In design synthesis, engineering prototypes make an ideal representation medium for preliminary designs. Unlike parametric design wherein a pre-specified design is parametrically varied, design synthesis demands artistic creativity and engineering experience to transform the previously known components, relationships and designs into a new form. The process compels the designer to ascertain which prototypes will, in some sense, best satisfy the design task. The challenge in this assignment lies in selecting the “right” design prototype. This selection process typically entails an objective evaluation of different designs that perform the same functions or have similar intended behavior and comparing trade-offs between alternate designs. This paper introduces a multi-objective spectral optimization algorithm for the selection of design prototypes based upon their functional representations. The optimization algorithm returns an index of rank, scoring the functional similarity of the proposed design to the goal design. Two illustrative examples apply the algorithm to the selection of a heat fin and beam.

Correction to: Genetic diversity and genetic variation in morpho-physiological traits to improve heat tolerance in Spring barley

2018 ◽  
Vol 46 (2) ◽  
pp. 2597-2597
Author(s):  
Ahmed Sallam ◽  
Ahmed Amro ◽  
Ammar Elakhdar ◽  
Mona F. A. Dawood ◽  
Toshihiro Kumamaru ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Heat Tolerance ◽  
Spring Barley ◽  
Physiological Traits

Genetic variation in an orchardgrass population promises successful direct or indirect selection of superior drought tolerant genotypes

2018 ◽  
Vol 137 (6) ◽  
pp. 928-935 ◽  
Author(s):  
Mozhgan Abtahi ◽  
Mohammad Mahdi Majidi ◽  
Behnam Hoseini ◽  
Aghafakhr Mirlohi ◽  
Bahram Araghi ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Indirect Selection ◽  
Drought Tolerant ◽  
Selection Of

Multi-objective optimization for safety and reliability trade-off: Optimization and results processing

2018 ◽  
Vol 232 (6) ◽  
pp. 661-676
Author(s):  
Cristina Johansson ◽  
Johan Ölvander ◽  
Micael Derelöv
Keyword(s):  
Decision Making ◽  
Solid Base ◽  
Multi Objective Optimization ◽  
Specific System ◽  
Multi Objective ◽  
Trade Offs ◽  
Design Alternatives ◽  
Safety And Reliability ◽  
Potential Issue ◽  
Selection Of

In early design phases, it is vital to be able to screen the design space for a set of promising design alternatives for further study. This article presents a method able to balance several objectives of different mathematical natures, with high impact on the design choices. The method (MOSART) handles multi-objective optimization for safety and reliability trade-offs. The article focuses on optimization problem approach and processing of results as a base for decision-making. The output of the optimization step is the selection of specific system elements obtaining the best balance between the targets. However, what is a good base for decision can easily transform into too much information and overloading of the decision-maker. To solve this potential issue, from a set of Pareto optimal solutions, a smaller sub-set of selected solutions are visualized and filtered out using preference levels of the objectives, yielding a solid base for decision-making and valuable information on potential solutions. Trends were observed regarding each system element and discussed while processing the results of the analysis, supporting the decision of one final best solution.

scholarly journals GENETIC VARIATION OF HUMPBACK GROUPER (Cromileptes altivelis) ON F1 AND F3 GENERATIONS

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Sari Budi Moria Sembiring ◽  
Tridjoko Tridjoko ◽  
Haryanti Haryanti
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Body Length ◽  
Quantitative Characteristic ◽  
Breeding Program ◽  
High Quality ◽  
Culture Technology ◽  
Selection Of ◽  
Rapd Method

Hatchery and culture technology of Humpback grouper has been developed. However,  sometimes it is still found constraint in sedd production and caused instability of production due to failure by many factors. Breeding program become necessary to provide seed with high quality and good genetic variation. Quantitative characteristic selection is one of breeding program to improve productivity in grouper aquaculture. The aim of this research was to produce good phenotyphic and genotypic quality of Humpback grouper candidate broodstock. Selection of Humpback grouper F1 and F3 was done based on quantitative characteristic (body length and weight) and genotyphic characteristic by using ramdom amplified polymorphism DNA (RAPD) method.  The results of conventional selection were found candidate broodstock of Humpback grouper F1 and F3 with body weight range from 170-210 g and 160-170 g consecutively.  Heterozygosity values of Humpback grouper analized by RAPD of F1 and F3 were 0.7940 and 0.7749 consecutively and it was not significantly different. This value emphasis that population of this F3 Humpback grouper was still good to grow for broodstock. Keywords: genetic variation, humpback grouper, F1, F3.

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