GENETIC VARIANCE COMPONENTS IN CULTIVATED STRAWBERRY

1970 ◽  
Vol 12 (1) ◽  
pp. 52-59 ◽  
Author(s):  
R. Watkins ◽  
L. P. S. Spangelo ◽  
A. T. Bolton
Keyword(s):  
Variance Components ◽  
Large Scale ◽  
Genetic Variance ◽  
Recurrent Selection ◽  
Small Scale ◽  
Relative Importance ◽  
Reciprocal Recurrent Selection ◽  
Genetic Progress ◽  
Total Genetic Variance ◽  
Large Scale Testing

Two methods of determining the relative importance of the additive, dominance and epistatic components of genetic variance indicated that the nonadditive variance (most of which was shown to be epistatic) constituted approximately 50% of the total genetic variance for 20 commercial characteristics of the cultivated strawberry. With nonadditive, particularly epistatic, variance being so important, genetic progress may best be achieved by a two-step breeding procedure involving small scale testing of all the progenies followed by large scale testing of the best progenies. Breeding procedures involving such methods as reciprocal recurrent selection, inbreeding and backcrossing would be more efficient as a means of generating special types of parents for such a program than they would be as isolated breeding procedures.

scholarly journals Genetic progress in maize from advanced cycles of reciprocal recurrent selection through REML/BLUP

2020 ◽  
pp. 1295-1301
Author(s):  
José Arantes Ferreira Júnior ◽  
Gabriel Moreno Bernardo Gonçalves ◽  
Jocarla Ambrosim Crevelari ◽  
Julio Cesar Fiorio Vettorazzi ◽  
Vivane Mirian Lanhellas Gonçalves ◽  
...  
Keyword(s):  
Grain Yield ◽  
Mixed Models ◽  
Variance Components ◽  
Genetic Parameters ◽  
Recurrent Selection ◽  
Yield Potential ◽  
Reciprocal Recurrent Selection ◽  
Genetic Progress ◽  
Advanced Cycles ◽  
Selection Of

Breeding methods such as reciprocal recurrent selection (RRS) is very important alternative to breeders. This strategy, besides allowing continuous genetic progress, helps maintaining the genetic variability of populations. The aim of the present study was to estimate genetic parameters, as well as to predict selection gains in advanced cycles of reciprocal recurrent selection of maize progenies through mixed models. Two selection cycles were considered. We evaluated 196 and 169 progenies in the 15 and 16 cycles, respectively. The yield potential of the progenies was evaluated from the following characteristics: grain yield, number of ears, weight of ears and weight of 100 seeds. The estimate of variance components and the prediction of genetic values were based on the REML/BLUP method. Overall, the genetic parameters were increased in the 16th cycle estimates compared to the previous cycle. It is worth highlighting that heritability coefficient for the grain yield was (0.81) in the 16th cycle, since it resulted in 21% of selection gain. Results showed that, even after sixteen recurrent selection cycles, the populations under selection have high potential for satisfactory genetic gains.

scholarly journals Estimates for Genetic Variance Components in Reciprocal Recurrent Selection in Populations Derived from Maize Single-Cross Hybrids

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Matheus Costa dos Reis ◽  
José Maria Villela Pádua ◽  
Guilherme Barbosa Abreu ◽  
Fernando Lisboa Guedes ◽  
Rodrigo Vieira Balbi ◽  
...  
Keyword(s):  
Plant Height ◽  
Genetic Variance ◽  
Recurrent Selection ◽  
Reciprocal Recurrent Selection ◽  
Additive Variance ◽  
Lattice Design ◽  
Single Cross ◽  
Covariance Components ◽  
Variance And Covariance Components ◽  
Single Cross Hybrids

This study was carried out to obtain the estimates of genetic variance and covariance components related to intra- and interpopulation in the original populations (C0) and in the third cycle (C3) of reciprocal recurrent selection (RRS) which allows breeders to define the best breeding strategy. For that purpose, the half-sib progenies of intrapopulation (P11and P22) and interpopulation (P12and P21) from populations 1 and 2 derived from single-cross hybrids in the 0 and 3 cycles of the reciprocal recurrent selection program were used. The intra- and interpopulation progenies were evaluated in a10×10triple lattice design in two separate locations. The data for unhusked ear weight (ear weight without husk) and plant height were collected. All genetic variance and covariance components were estimated from the expected mean squares. The breakdown of additive variance into intrapopulation and interpopulation additive deviations (στ2) and the covariance between these and their intrapopulation additive effects (CovAτ) found predominance of the dominance effect for unhusked ear weight. Plant height for these components shows that the intrapopulation additive effect explains most of the variation. Estimates for intrapopulation and interpopulation additive genetic variances confirm that populations derived from single-cross hybrids have potential for recurrent selection programs.

The Use of Large Scale Parameters in Small Scale Diffusion Studies

1957 ◽  
Vol 38 (1.1) ◽  
pp. 6-12 ◽  
Author(s):  
William G. Tank
Keyword(s):  
Large Scale ◽  
Meteorological Parameters ◽  
Surface Wind ◽  
Small Scale ◽  
Relative Importance ◽  
Wind Vector ◽  
Scale Parameters ◽  
Diffusion Studies ◽  
The Mean ◽  
Low Levels

A method is set forth whereby gaseous diffusion in the low levels of the atmosphere can be calculated by Roberts' diffusion equation (modified to consider instantaneous volume sources) using only large scale synoptic parameters that are readily obtainable from the surface analysis and pibal reports. The three pertinent meteorological parameters utilized are: (1) the mean surface wind, (2) the angle between the surface wind vector and the surface isobars, and (3) the height of the gradient level. Theoretical and observed dosage values are compared by means of dosage isopleth diagrams. Results show that the method yields quite satisfactory results, with regard to both dosage magnitude and distribution. The assumptions necessary for the application of the method and its limitations are mentioned and their relative importance discussed.

scholarly journals GENETIC PROGRESS IN 20 YEARS OF RECIPROCAL RECURRENT SELECTION IN MAIZE

2020 ◽  
Vol 2 (1) ◽  
pp. 13-23
Author(s):  
José Arantes Ferreira Júnior ◽  
Gabriel Moreno Bernardo Gonçalves ◽  
Jocarla Ambrosim Crevelari ◽  
Yure Pequeno de Souza ◽  
Vivane Mirian Lanhellas Gonçalves ◽  
...  
Keyword(s):  
Recurrent Selection ◽  
Reciprocal Recurrent Selection ◽  
Genetic Progress

scholarly journals Testing & Opening in Augustusburg A Success Story?

2021 ◽  
Author(s):  
Marc Diederichs ◽  
Timo Friedel Mitze ◽  
Felix Schulz ◽  
Klaus Waelde
Keyword(s):  
Disease Surveillance ◽  
Large Scale ◽  
Community Level ◽  
Small Scale ◽  
County Level ◽  
Success Story ◽  
Large Scale Testing ◽  
The City ◽  
Better Than

The city of Augustusburg allowed for opening of, inter alia, restaurants and hotels joint with large-scale testing. We evaluate this testing & opening (T&O) experiment by comparing the evolution of case rates in Augustusburg with the evolution in other communities of Saxony. We have access to small-scale SARS-CoV-2 infection data at the community level (Gemeinde) instead of the county level (Landkreis) usually used for disease surveillance. Despite data challenges, we conclude that T&O did not lead to any increase in case rates in Augustusburg compared to its control county. When we measure the effect of T&O on cumulative cases, we find a small increase in Augustusburg. This difference almost completely disappears when we control for the effect of higher case rates due to more testing. Generally speaking, T&O worked much better than in comparable projects elsewhere.

scholarly journals The Implementation of Student Worksheets (LKM) on Relations and Functions through Website-based guided-inquiry approach student worksheet

2020 ◽  
Vol 3 (2) ◽  
pp. 169-174
Author(s):  
Netriwati Netriwati ◽  
Busmayaril Busmayaril
Keyword(s):  
Learning Outcomes ◽  
Teaching And Learning ◽  
Large Scale ◽  
Average Score ◽  
Small Scale ◽  
Guided Inquiry ◽  
Inquiry Approach ◽  
Learning Mathematics ◽  
Large Scale Testing ◽  
Motivation And Learning

Student Worksheet is a learning media that can be used as a guide for students and lecturers in the teaching and learning process. The developed product of this research is a website-based guided-inquiry approach student worksheet. The purpose of this study is to improve students’ learning outcomes and motivation in learning mathematics. This research employed the pre-experimental method with one-group pretest-posttest design. The small-scale testing obtained an average score of 3.1 which is included in the interesting category. The large-scale testing obtained an average score of 3.26 which is included in the very interesting category. The website-based guided-inquiry approach student worksheet obtained an average score of 0.48 which is included in the medium category for its effectiveness. It can be concluded that the website-based guided-inquiry approach student worksheet is feasible and very interesting to be used in increasing student motivation and learning outcomes for better learning in Basic Mathematics course.

scholarly journals Pengembangan Buku Ajar Penanganan dan Terapi Cedera Olahraga

2020 ◽  
Vol 5 (1) ◽  
pp. 40-50
Author(s):  
Rahmat Sanusi ◽  
Fadli Surahman ◽  
Hilda Oktri Yeni
Keyword(s):  
Data Analysis ◽  
Physical Education ◽  
Large Scale ◽  
Descriptive Analysis ◽  
Expert Judgment ◽  
Small Scale ◽  
Text Book ◽  
Data Analysis Technique ◽  
Analysis Technique ◽  
Large Scale Testing

The aim of this research is generating a text book of treatment dan injuries therapy in sports for students of physical education and recreation program at Karimun University. The study is a research of developing that refers to Borg and Gall desain that involving four validators, those are lecture as user, therapist, masseur dan media expert. Small-scale testing involves 10 students and large-scale testing involves 30 students. The data collecting in this research uses the implementation test and expert judgment by using questionnaire sheet and competition test with data analysis technique using descriptive analysis. The results of research that obtained based on validator assessment that is user lecturer, therapist, masseur, and media expert, are in “Good” category. The result of usage assessment and competition test from students shows in “Good” category. Based on this data, it can be conlcuded that the developing of text book of treatment and  injuries therapy in sports is feasible and effective to be used.

scholarly journals Additive and Non-Additive Genetic Variances for Tree Growth in Several Hybrid Poplar Populations and Implications Regarding Breeding Strategy

2017 ◽  
Vol 66 (1) ◽  
pp. 33-39 ◽  
Author(s):  
W.E. Berguson ◽  
B.G. McMahon ◽  
D.E. Riemenschneider
Keyword(s):  
Growth Rate ◽  
Genetic Variance ◽  
Recurrent Selection ◽  
Clonal Selection ◽  
Broad Sense ◽  
Mass Selection ◽  
Improvement Strategy ◽  
Pure Species ◽  
Total Genetic Variance ◽  
Selection Of

Abstract Populus species (P. deltoides, P. maximowiczii, P. nigra) and their inter-specific hybrids were tested for growth rate over a five year period at four test locations in Minnesota, USA, to estimate genetic variance components. The breeding scheme incorporated recurrent selection of full-sib families of pure species parents, production of F1 inter-specific hybrids from selected families, and selection of clones within the F1s. Improvement of yield through time using this scheme is predicated on the assumption that additive effects comprise a significant portion of the total genetic variance. The estimates of additive and non-additive variances reported are not traditional point estimates, because a fully balanced mating design was impossible due to parental incompatibilities which result in incomplete breeding matrices. Instead, bounded estimates, not previously used in tree genetics research, are derived from linear combinations of formulae of genetic expectations observed among-family, among-clone, and environmental variances. Our results suggest that combined family and mass selection would lead to increases in growth rate of 27 % and 47 % per generation in P. deltoides and P. nigra, respectively. Broad sense-based clonal selection within the F1 could yield selection responses in excess of 90 % of the mean of such populations. Among-family variance comprised about 1/3 of total genetic variance while within-family variance was always about 2/3 of total genetic variance, regardless of pedigree. The results indicate that recurrent intraspecific selective breeding followed by interspecific hybridization and non-recurrent selection based on broad sense genetic variation would constitute an effective yield improvement strategy.

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