Correspondence of performance between genetically related clones and seedlings

1995 ◽  
Vol 25 (3) ◽  
pp. 500-506 ◽  
Author(s):  
Nuno M.G. Borralho ◽  
Peter J. Kanowski

The correspondence of the performance between genetically related vegetative propagules and seedlings, as expressed by the correlation between (1) rejuvenated propagules and seedling progeny of the same parent, (2) vegetative propagules and seedlings from the same family, and (3) seedlings and vegetative propagules taken from them, was investigated. In the absence of propagation effects, expected correlations improved with increasing additive variance and the number of seedlings and propagules tested, and ranged between moderate and high. Effects due to nonadditive genetic variance varied from unimportant, in the case of seedlings and vegetative propagules of the same family, to large, in the case of seedlings and their propagules. Simulation studies demonstrated that propagation effects common to specific clones (C-effects) resulted in a significant reduction in the magnitude of correlations if the covariance with true genetic effects is negative or zero, but had little effect when the covariance is positive. Propagation effects affecting all ramets equally (c-effects) did not cause any change in the correlations. Generally, comparisons between rejuvenated propagules and seedling progeny resulted in higher correlations, and were less affected by propagation effects, than other comparisons. They were also more robust against departures from assumptions of open-pollinated family structure. Results from empirical studies seem to agree well with expectations and suggest that propagation effects might be involved on the correspondence between genetically related clones and seedlings. Implications for selection and clonal deployment strategies need further investigation.

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Akio Onogi ◽  
Toshio Watanabe ◽  
Atsushi Ogino ◽  
Kazuhito Kurogi ◽  
Kenji Togashi

Abstract Background Genomic prediction is now an essential technology for genetic improvement in animal and plant breeding. Whereas emphasis has been placed on predicting the breeding values, the prediction of non-additive genetic effects has also been of interest. In this study, we assessed the potential of genomic prediction using non-additive effects for phenotypic prediction in Japanese Black, a beef cattle breed. In addition, we examined the stability of variance component and genetic effect estimates against population size by subsampling with different sample sizes. Results Records of six carcass traits, namely, carcass weight, rib eye area, rib thickness, subcutaneous fat thickness, yield rate and beef marbling score, for 9850 animals were used for analyses. As the non-additive genetic effects, dominance, additive-by-additive, additive-by-dominance and dominance-by-dominance effects were considered. The covariance structures of these genetic effects were defined using genome-wide SNPs. Using single-trait animal models with different combinations of genetic effects, it was found that 12.6–19.5 % of phenotypic variance were occupied by the additive-by-additive variance, whereas little dominance variance was observed. In cross-validation, adding the additive-by-additive effects had little influence on predictive accuracy and bias. Subsampling analyses showed that estimation of the additive-by-additive effects was highly variable when phenotypes were not available. On the other hand, the estimates of the additive-by-additive variance components were less affected by reduction of the population size. Conclusions The six carcass traits of Japanese Black cattle showed moderate or relatively high levels of additive-by-additive variance components, although incorporating the additive-by-additive effects did not improve the predictive accuracy. Subsampling analysis suggested that estimation of the additive-by-additive effects was highly reliant on the phenotypic values of the animals to be estimated, as supported by low off-diagonal values of the relationship matrix. On the other hand, estimates of the additive-by-additive variance components were relatively stable against reduction of the population size compared with the estimates of the corresponding genetic effects.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Frederik Booysen ◽  
Ferdi Botha ◽  
Edwin Wouters

AbstractSocial determinants of health frameworks are standard tools in public health. These frameworks for the most part omit a crucial factor: the family. Socioeconomic status moreover is a prominent social determinant of health. Insofar as family functioning is poorer in poor families and family structure and functioning are linked to health, it is critical to consider the pathways between these four constructs. In this correspondence, we reflect on how empirical studies of this conceptual nexus mirror two causal models. We conclude by reflecting on future directions for research in this field.


Genetika ◽  
2004 ◽  
Vol 36 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Mile Secanski ◽  
Tomislav Zivanovic ◽  
Goran Todorovic ◽  
Gordana Surlan-Momirovic

The aim of the present study was to evaluate the following parameters for the grain yield of silage maize: variability of inbred lines and their diallel hybrids, superior-parent heterosis and components of genetic variability and heritability on the basis of the diallel set. The two-year four-replicate trial was set up according to the randomized complete-block design at Zemun Polje. It was determined that a genotype, year and their interaction significantly affected variability of this trait. The highest. i.e. the lowest grain yield, on the average for both investigation years. was recorded in the silage maize inbred lines ZPLB402 and ZPLB405. respectively. The analysis of components of genetic variance for grain yield shows that the additive component (D) was lower than the dominant (H1 and H2) genetic variance, while a positive component F and the frequency of dominant (u) and recessive (v) genes for this observed trait point to prevalence of dominant genes over recessive ones. Furthermore. this is confirmed by the ratio of dominant to recessive genes in parental genotypes for grain yield (Kd/Kr> 1) that is greater than unity in both years of investigation. The estimated value of the average degree of dominance (H1/D)1/2 exceeds unity, pointing out to superdominance in inheritance of this trait in both years of investigation. Results of Vr/Vr regression analysis indicate superdominance in inheritance of grain yield. Moreover. a registered presence of non-allelic interaction points out to the need to study effects of epistasis, as it can have a greater significance in certain hybrids. A greater value of dominant than additive variance resulted in high values of broad-sense heritability for grain yield in both investigation years (98.71%, i.e. 97.19% in 1997, i.e. 1998, respectively). and low values of narrow-sense heritability (11.9% in 1997 and 12.2% in 1998).


2019 ◽  
Vol 51 (1) ◽  
Author(s):  
Luis Varona ◽  
Juan Altarriba ◽  
Carlos Moreno ◽  
María Martínez-Castillero ◽  
Joaquim Casellas

Abstract Background Inbreeding is caused by mating between related individuals and its most common consequence is inbreeding depression. Several studies have detected heterogeneity in inbreeding depression among founder individuals, and recently a procedure for predicting hidden inbreeding depression loads associated with founders and the Mendelian sampling of non-founders has been developed. The objectives of our study were to expand this model to predict the inbreeding loads for all individuals in the pedigree and to estimate the covariance between the inbreeding loads and the additive genetic effects for the trait of interest. We tested the proposed approach with simulated data and with two datasets of records on weaning weight from the Spanish Pirenaica and Rubia Gallega beef cattle breeds. Results The posterior estimates of the variance components with the simulated datasets did not differ significantly from the simulation parameters. In addition, the correlation between the predicted and simulated inbreeding loads were always positive and ranged from 0.27 to 0.82. The beef cattle datasets comprised 35,126 and 75,194 records on weights between 170 and 250 days of age, and pedigrees of 308,836 and 384,434 individual-sire-dam entries for the Pirenaica and Rubia Gallega breeds, respectively. The posterior mean estimates of the variance of inbreeding depression loads were 29,967.8 and 28,222.4 for the Pirenaica and Rubia Gallega breeds, respectively. They were larger than those of the additive variance (695.0 and 439.8 for Pirenaica and Rubia Gallega, respectively), because they should be understood as the variance of the inbreeding depression achieved by a fully inbred (100%) descendant. Therefore, the inbreeding loads have to be rescaled for smaller inbreeding coefficients. In addition, a strong negative correlation (− 0.43 ± 0.10) between additive effects and inbreeding loads was detected in the Pirenaica, but not in the Rubia Gallega breed. Conclusions The results of the simulation study confirmed the ability of the proposed procedure to predict inbreeding depression loads for all individuals in the populations. Furthermore, the results obtained from the two real datasets confirmed the variability in the inbreeding depression loads in both breeds and suggested a negative correlation of the inbreeding loads with the additive genetic effects in the Pirenaica breed.


2019 ◽  
Vol 30 (4) ◽  
pp. 433-450 ◽  
Author(s):  
Toula Kourgiantakis ◽  
Karen M. Sewell ◽  
Ran Hu ◽  
Judith Logan ◽  
Marion Bogo

Purpose: This article presents a scoping review that synthesized empirical studies on simulation in social work (SW) education. The review maps the research examining characteristics of simulation studies in SW education and emerging best practices. Method: Using Arksey and O’Malley’s scoping review framework to develop the methodology and following the PRISMA-ScR checklist, we selected 52 studies for this review. Results: Most studies were published in North America and included quantitative (37%), qualitative (31%), and mixed methods (33%). Simulation was used to teach generalist and specialized practice with interprofessional practice as the highest area of specialization. Simulation was also used for assessment purposes, and the Objective Structured Clinical Examination was a commonly reported method. We identified several facilitators and barriers to using simulation effectively for teaching and assessment. Conclusions: Our analysis permitted us to identify emerging best practices that can be used to guide teaching. Implications for SW research, teaching, and practice are discussed.


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 ◽  
...  

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.


Euphytica ◽  
2009 ◽  
Vol 167 (3) ◽  
pp. 397-408 ◽  
Author(s):  
Johnie N. Jenkins ◽  
Jack C. McCarty ◽  
Jixiang Wu ◽  
Osman A. Gutierrez

PLoS Genetics ◽  
2021 ◽  
Vol 17 (5) ◽  
pp. e1009548
Author(s):  
Valentin Hivert ◽  
Naomi R. Wray ◽  
Peter M. Visscher

Fisher’s partitioning of genotypic values and genetic variance is highly relevant in the current era of genome-wide association studies (GWASs). However, despite being more than a century old, a number of persistent misconceptions related to nonadditive genetic effects remain. We developed a user-friendly web tool, the Falconer ShinyApp, to show how the combination of gene action and allele frequencies at causal loci translate to genetic variance and genetic variance components for a complex trait. The app can be used to demonstrate the relationship between a SNP effect size estimated from GWAS and the variation the SNP generates in the population, i.e., how locus-specific effects lead to individual differences in traits. In addition, it can also be used to demonstrate how within and between locus interactions (dominance and epistasis, respectively) usually do not lead to a large amount of nonadditive variance relative to additive variance, and therefore, that these interactions usually do not explain individual differences in a population.


2017 ◽  
Vol 28 (2) ◽  
pp. 455
Author(s):  
Luis Ángel Muñoz Romero ◽  
Enrique Navarro Guerrero ◽  
Manuel De la Rosa Ibarra ◽  
Luis Pérez Romero ◽  
Ángel Enrique Caamal Dzul

The aim of this work was to estimate the combinatory aptitude, genetic variance and heterosis of eight creole corn varieties. The research work was carried in Irapuato, Guanajuato, México, during 2008 and 2009. A randomized complete block design with three replications was used to evaluate the twenty-eight crosses under method 4 Griffing (1956). Each experimental plot included four rows five meters long with a separation of 0,75 m. The general combing ability and specific (ACG and ACE) were highly significant (P<0.01) for all traits except flowering days. The dominance variance (σ2D) was larger and more important than additive variance (σ2A) for most of the traits, indicating that non- additive genetic genes were important on the expression of those traits on crosses. It was observed that varieties P6 (creole #5), P7 (creole #2) and P8 (creole San Antonio) had larger variance effects (σ2ACE) for long cob, number of rows per cob, total cob number, and grain yield. Some outstanding crosses were identified for their high grain yield as well as heterosis, mainly those that included germoplasm of creole #5, #2 and San Antonio. According to the aforementioned we recommend to draw lines from the above populations and cross them to produce hybrids. 


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