ADDITIVE AND NONADDITIVE GENETIC VARIANCES AND GENOTYPIC CORRELATIONS FOR YIELD AND OTHER TRAITS IN OATS

1971 ◽  
Vol 13 (4) ◽  
pp. 864-872 ◽  
Author(s):  
D. R. Sampson
Keyword(s):  
Seed Weight ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Heading Date ◽  
Stem Diameter ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Plot Yield ◽  
Panicle Number

The oat cultivate 'Dorval', 'Kelsey', 'Stormont', 'Orbit', 'Goodfield', 'Tyler' and 'Egdolon' and two numbered lines were crossed in a 3 × 6 factorial design. F1's, F2's and bullied F2 progenies were grown in successive years at seeding rates of 2.7, 9.5 and at the commercial rare of 76 Kg/ha, respectively; the F1's in irrigated cages, the F2's and F3's in nonirrigated fields. Additive genetic variance was the most important component of the phenotypic variances among progenies. Major differences occurred between the F1's and F2's, but the F2's and F3's agreed closely. The percentages of additive variance (narrow sense heritability) for the joint F2, F3 analyses were: height (91); heading date (87); seed weight (74); yield per panicle (71); seeds per panicle (63); panicle number (58); stem diameter (55); plot yield (52). Important nonadditive variance was present in the F2, F3 data for plot yield (17%), stem diameter (15%) and seed weight (12%). All traits were positively correlated with each other in the F1's. Correlations were weaker in the F2 and F3 and reversed for panicle number. Seed weight showed the least correlation with other traits. These results are discussed from the practical viewpoint of combining strong straw with high grain yield. The usefulness of selecting for seed weight and panicle yield to improve plot yield is underlined.

scholarly journals Efficiencies of Clonally Replicated and Seedling Testing for Spruce Breeding and Deployment Strategies

2009 ◽  
Vol 58 (1-6) ◽  
pp. 292-300
Author(s):  
Y. H. Weng ◽  
Y. S. Park ◽  
D. Simpson ◽  
T. J. Mullin
Keyword(s):  
Genetic Variance ◽  
Gene Diversity ◽  
Additive Genetic Variance ◽  
Seed Orchard ◽  
Narrow Sense ◽  
Family Selection ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Clonal Seed Orchard ◽  
Seedling Test

AbstractGenetic gains based on a genetic test using clonal replicates were compared to those based on a test using seedlings at the same gene diversity and testing effort levels using POPSIM™ Simulator. Three testing and deployment strategies targeting for white spruce (P. glauca [Moench] Voss) and black spruce (P. mariana (Mill.) B.S.P.) in New Brunswick were compared: seedling test with clonal seed orchard deployed as seedlings (CSO_ST), clonally replicated test with clonal seed orchard deployed as seedlings (CSO_CRT), and clonally replicated test deployed as a clone mix (MVF). The breeding populations (BP) were formed by balanced within-family selection and the production populations (PP) were selected by strong restriction on relatedness, i.e., no parent in common. Compared to the seedling test, the clonally replicated test resulted in faster accumulation of additive effects but quicker loss of additive variance in the BP, and this is particular true in the case of lower narrow-sense heritability or less non-additive genetic variance. The quicker loss in BP additive variance was overcompensated for by its faster accumulation in BP additive effect, resulting in higher gain in the clonally replicated test based PPs. Compared to the CSO_ST, the gain superiority of the CSO_CRT increased with generations, decreasing narrow-sense heritability or reducing the amount of non-additive variance. Implementing MVF was the most effective in terms of gain in most simulated cases and its superiority over the CSO_ST increased with generations, decreasing narrowsense heritability, or increasing non-additive genetic variance. Overall results demonstrated significant advantages of using clonally replicated test both for BP advancement and PP selection in most of the scenarios, suggesting that clonally replicated test should be incorporated into current spruce breeding strategies.

GENETIC VARIANCES IN AN EIGHT PARENT HALF DIALLEL OF OATS

1976 ◽  
Vol 18 (3) ◽  
pp. 419-427 ◽  
Author(s):  
D. R. Sampson ◽  
I. Tarumoto
Keyword(s):  
Grain Yield ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Heading Date ◽  
Phenotypic Variance ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Additive Component ◽  
Tests Of Fit ◽  
Half Diallel

Twenty-eight progenies with their eight parent cultivars of Avena saliva L. (2n = 6x = 42) were grown in F1, F2 and F3 in separate years; the F1 as spaced plants, the F2 and F3 as dense seeded populations. Additive genetic variance constituted most of the phenotypic variance of eight traits (heading date, plant height, stem diameter, grain yield and four components of yield) according to a Griffing Method 4, Model II analysis. Similarly, additive × year interactions were more important than nonadditive × year interactions. A Hayman-Jinks analysis of the same material but with the parents included showed that the additive component was 2 to 16 times larger than the dominance components in the F1 However in the F2 and F3 the dominance components became larger than the additive components for most traits instead of declining in importance as expected. Further, tests of fit to the hypotheses underlying the Hayman-Jinks analysis were negative in 8 of 24 cases. It is postulated that these discrepancies result from epistatic variance which caused an upward bias in the dominance estimates. The calculation and uses of two estimates of narrow-sense heritability are discussed.

scholarly journals Estimation of Genetic Parameter for Quantitative Characters of Pepper (Capsicum annuum L.)

2014 ◽  
Vol 1 (1) ◽  
pp. 4-8 ◽  
Author(s):  
Muhamad Syukur ◽  
Syaidatul Rosidah
Keyword(s):  
Plant Height ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Stem Diameter ◽  
Broad Sense Heritability ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Fruit Length ◽  
Quantitative Characters

The research was conducted at Leuwikopo Experimental Field and Plant Breeding Laboratory of IPB, Dramaga, Bogor, West Java, Indonesia from October 2012 to April 2013. Crossing population between C15 and C2 genotype were used to study genetic parameters for quantitative characters in pepper. All the characters were not controlled by maternal effect, except fruit length. Broad-sense heritability were high for plant height, stem diameter, dichotomous height, days to flower, days to harvest; and medium for fruit length and diameter. Narrow-sense heritability was high for stem diameter, dichotomous height, days for flowering; medium for plant height, days to harvest; and low for fruit length and diameter. The ratio of additive variance was high for all the characters, except for fruit length and fruit diameter.Keywords: heritability, heterosis, heterobeltiosis, additive variance, dominant variance

scholarly journals Narrow-sense heritability estimation of complex traits using identity-by-descent information

2017 ◽  
Author(s):  
Luke M. Evans ◽  
Rasool Tahmasbi ◽  
Matthew Jones ◽  
Scott I. Vrieze ◽  
Gonçalo R. Abecasis ◽  
...  
Keyword(s):  
Complex Traits ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Fundamental Parameter ◽  
Last Common Ancestor ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Heritability Estimation ◽  
Causal Variants ◽  
Heritability Estimates

ABSTRACTHeritability is a fundamental parameter in genetics. Traditional estimates based on family or twin studies can be biased due to shared environmental or non-additive genetic variance. Alternatively, those based on genotyped or imputed variants typically underestimate narrow-sense heritability contributed by rare or otherwise poorly-tagged causal variants. Identical-by-descent (IBD) segments of the genome share all variants between pairs of chromosomes except new mutations that have arisen since the last common ancestor. Therefore, relating phenotypic similarity to degree of IBD sharing among classically unrelated individuals is an appealing approach to estimating the near full additive genetic variance while avoiding biases that can occur when modeling close relatives. We applied an IBD-based approach (GREML-IBD) to estimate heritability in unrelated individuals using phenotypic simulation with thousands of whole genome sequences across a range of stratification, polygenicity levels, and the minor allele frequencies of causal variants (CVs). IBD-based heritability estimates were unbiased when using unrelated individuals, even for traits with extremely rare CVs, but stratification led to strong biases in IBD-based heritability estimates with poor precision. We used data on two traits in ~120,000 people from the UK Biobank to demonstrate that, depending on the trait and possible confounding environmental effects, GREML-IBD can be applied successfully to very large genetic datasets to infer the contribution of very rare variants lost using other methods. However, we observed apparent biases in this real data that were not predicted from our simulation, suggesting that more work may be required to understand factors that influence IBD-based estimates.

scholarly journals Narrow-Sense Heritability of Selected Sensory Descriptors in Virginia-Type Peanut (Arachis hypogaea L.)1

2003 ◽  
Vol 30 (1) ◽  
pp. 64-66 ◽  
Author(s):  
T. G. Isleib ◽  
H. E. Pattee ◽  
F. G. Giesbrecht
Keyword(s):  
Arachis Hypogaea ◽  
Genetic Variance ◽  
Genetic Model ◽  
Additive Genetic Variance ◽  
Narrow Sense ◽  
Roasted Peanut ◽  
Narrow Sense Heritability ◽  
Breeding Lines ◽  
Arachis Hypogaea L ◽  
F2 Generation

Abstract The sweet, bitter and roasted peanut attributes of roasted peanut (Arachis hypogaea L.) flavor have been shown to be heritable traits. Previous research has estimated broad-sense heritability (H) and breeding values of numerous peanut cultivars and breeding lines for these attributes, but no study has estimated narrow-sense heritability (h2) in a specific population derived through hybridization and inbreeding. A population of 120 F3-derived families was developed without selection from the cross of NC 7/NC Ac 18431, a virginia-type line identified in 1990 as having a good flavor profile. The parents and F3:5 families were grown at two locations in North Carolina in 1995. SMK samples from each plot were roasted, ground to paste, tasted by a sensory panel, and scored for roasted peanut, sweet, bitter and astringent attributes. Additive and nonadditive genetic variances were estimated by equating variances among F2-derived families and among F3-derived families within F2-derived families to genetic covariances among inbred relatives. Regardless of whether the genetic model included dominance or additive-by-additive epistasis, the estimates of additive genetic variance for flavor attributes were small compared to those for nonadditive genetic variance. Narrow-sense heritability in the F2 generation was estimated at 0 for roasted peanut and astringent, 0.02 to 0.04 for sweet, and 0.01 to 0.03 for bitter, depending on the model used. Because of the low values of h2, which are specific to this population, gain from selection in early generations is expected to be limited within this population. Selection in this population should be practiced in late generations. Other parents have been identified whose crosses should produce greater improvement in sensory quality than can be expected from the NC 7 / NC Ac 18431 population.

scholarly journals The source of additive genetic variance of evolutionarily important traits

2019 ◽  
Author(s):  
Li Liu ◽  
Yayu Wang ◽  
Di Zhang ◽  
Xiaoshu Chen ◽  
Zhijian Su ◽  
...  
Keyword(s):  
Natural Selection ◽  
Fundamental Theorem ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Adaptive Divergence ◽  
Population Admixture ◽  
Strong Positive Correlation ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Fisher’S Fundamental Theorem

AbstractFisher’s fundamental theorem of natural selection predicts no additive variance of fitness in a natural population. Consistently, observations in a variety of wild populations show virtually no narrow-sense heritability (h2) for traits important to fitness. However, counterexamples are occasionally reported, calling for a deeper understanding on the evolution of additive variance. In this study we propose adaptive divergence followed by population admixture as a source of the additive genetic variance of evolutionarily important traits. We experimentally tested the hypothesis by examining a panel of ~1,000 yeast segregants produced by a hybrid of two yeast strains that experienced adaptive divergence. We measured over 400 yeast cell morphological traits and found a strong positive correlation between h2 and evolutionary importance. Because adaptive divergence followed by population admixture could happen constantly, particularly in some species such as humans, the finding reconciles the observation of abundant additive variances in evolutionarily important traits with Fisher’s fundamental theorem of natural selection. It also suggests natural selection may effectively promote rather than suppress additive genetic variance in species with wide geographic distribution and strong migratory capacity.

scholarly journals Genetic Parameters for Traits Related to Mechanized Harvesting in a Cucumber (Cucumis sativus L.) Population

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 796D-796 ◽  
Author(s):  
F. Serquen ◽  
J. Staub
Keyword(s):  
Genetic Parameters ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Stem Length ◽  
Cucumber Plant ◽  
Individual Plant ◽  
Narrow Sense Heritability ◽  
Cucumis Sativus L ◽  
Additive Variance ◽  
Plant Ideotype

Sex expression (SE), stem length (SL), and number of laterals plant (NL) are important morphological traits of a cucumber plant ideotype adapted for machine harvesting. Two inbred lines, the determinate, gynoecious G-421, possessing high fruit quality, and the monoecious H-19, with multiple lateral branching and sequential fruiting habit, and their F1 and F3 (100) progenies were planted in Wisconsin and Georgia. Data on SE, SL, and NL were recorded on individual plant basis. Genetic parameters were estimated using all generations. Phenotypic correlations were calculated from the trait means, and genotypic correlations were estimated from the analysis of variance of F3 progeny. The additive genetic variance was the highest of the variance components for SL and NL. Dominance genetic variance was more important than the additive variance for the control of SE. Narrow-sense heritability were 0.41, 0.83, and 0.85 for SE, SL, and NL, respectively. The genotypic (g) and phenotypic (p) correlation coefficients (r) indicated negative association between SE and SL (rg = –0.57, rp = –0.45**) and between SE and NL (rg = –0.56, rp = –0.27**). The association between SL and NL was positive (rg = 0.63, rp = 0.35**). Results suggest that gain from selection can be made for this plant ideotype.

scholarly journals Selection strategies of segregant soybean populations for resistance to Asian rust

2009 ◽  
Vol 44 (11) ◽  
pp. 1452-1459 ◽  
Author(s):  
Aliny Simony Ribeiro ◽  
José Francisco Ferraz de Toledo ◽  
Magno Antonio Patto Ramalho
Keyword(s):  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Infected Leaf ◽  
Good Resistance ◽  
Narrow Sense Heritability ◽  
Growing Seasons ◽  
Selection Strategies ◽  
Line Selection ◽  
Soybean Resistance ◽  
Selection Of

The objective of this work was to identify the best selection strategies for the more promising parental combinations to obtain lines with good resistance to soybean Asian rust (Phakopsora pachyrhizi). Two experiments were carried out in the field during the 2006/2007 and 2007/2008 growing seasons, to determine the percentage of infected leaf area of individual plants of five parents and their segregant F2 and F3 populations. The data obtained indicates that additive genetic variance predominates in the control of soybean resistance to Asian rust, and that the year and time of assessment do not significantly influence the estimates of the genetic parameters obtained. The narrow-sense heritability (h²r) ranged from 23.12 to 55.83%, and indicates the possibility of successful selection of resistant individuals in the early generations of the breeding program. All the procedures used to select the most promising populations to generate superior inbred lines for resistance to P. pachyrhizi presented similar results and identified the BR01-18437 x BRS 232 population as the best for inbred line selection.

scholarly journals Components of genetic variability and heritability of grain yield of silage maize

Genetika ◽  
2004 ◽  
Vol 36 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Mile Secanski ◽  
Tomislav Zivanovic ◽  
Goran Todorovic ◽  
Gordana Surlan-Momirovic
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Genetic Variance ◽  
Block Design ◽  
Inbred Lines ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Silage Maize ◽  
V Genes ◽  
Set Up

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).

scholarly journals DYNAMICS OF HERITABILITY IN DIFFERENT CHARACTERS OF LETTUCE

2021 ◽  
Vol 34 (3) ◽  
pp. 514-526
Author(s):  
ALISSON HENRIQUE GAMA DE OLIVEIRA ◽  
GABRIEL MASCARENHAS MACIEL ◽  
ANA CAROLINA SILVA SIQUIEROLI ◽  
JOSÉ MAGNO QUEIROZ LUZ ◽  
ERNANI CLARETE DA SILVA
Keyword(s):  
Chlorophyll Content ◽  
Gene Action ◽  
Gene Interactions ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Dominant Type ◽  
Partial Dominance ◽  
Number Of Genes ◽  
Number Of Leaves

ABSTRACT The lack of knowledge of the genetic parameters and the type of gene action results in difficulties to obtain varieties that combine agronomic and functional characteristics. The objective of this study was to determine the type of gene action associated with the contents of chlorophyll and agronomic characteristics in lettuce populations. The research was conducted at the Experimental Station of Vegetables, Monte Carmelo, Brazil. To perform the crosses and obtain the generations P1, P2, F1, F2, Bc1 and Bc2 the genotypes UFU-Albina#2, UFU-Albina#3, UFU-Lisa124#2#1, UFU-Crespa199#1#1 and UFU-Lisa217#5#2 were used as parents. The generations were evaluated for three characteristics: number of leaves, plant diameter and chlorophyll content. The parameters: genetic, phenotypic, environmental and additive variance, the dominance in F2, heritability in the broad and narrow-sense, the average degree of dominance based on averages, number of genes, the measure of the dominance deviations, additive effects and all interactions of ‘additive x additive’, ‘additive x dominant’ and ‘dominant x dominant’ type, were evaluated. Chlorophyll content was the most influenced by the environment. Plant diameter had the highest narrow-sense heritability for the cross UFU-Lisa-124#2#1 x UFU-Albina#3 (82.1%). The number of genes for the number of leaves varied from inconclusive to a minimum of 9 genes. The gene interactions for number of leaves were of overdominance type, while for plant diameter and for chlorophyll content the gene interactions were of partial dominance. The characteristics are suggested as being of polygenic or oligogenic nature.

Sign in / Sign up

Export Citation Format

Share Document