Estimating single gene effects on quantitative traits

1985 ◽  
Vol 69-69 (5-6) ◽  
pp. 625-629 ◽  
Author(s):  
D. G. Gilbert
2010 ◽  
Vol 53 (6) ◽  
pp. 731-733
Author(s):  
B. Buske ◽  
N. Gengler

Abstract. Knowledge of major gene effects for quantitative traits (e.g. milk performance traits) and the consequent selection of animals with desirable genotypes can accelerate breeding progress and can therefore equal large gain in profits. It is generally accepted that in most cases, the total breeding value for quantitative traits of any animal can be divided in one or some major gene effects and a pure random polygenic component, in which the latter results from a finite number of remaining loci (FERNANDO et al. 1994). Thus, the aim of this study was to investigate, how the estimation of heritability is influenced by the application of two different models, one of them containing a major single gene effect. The myostatin gene (MSTN) was chosen because the knowledge of this gene effect is used for selection decisions in the Dual Purpose Belgian Blue Breed (DP-BBB) in the Walloon Region of Belgium.


Genetics ◽  
1999 ◽  
Vol 153 (4) ◽  
pp. 2001-2012 ◽  
Author(s):  
Bruno Bost ◽  
Christine Dillmann ◽  
Dominique de Vienne

Abstract The fluxes through metabolic pathways can be considered as model quantitative traits, whose QTL are the polymorphic loci controlling the activity or quantity of the enzymes. Relying on metabolic control theory, we investigated the relationships between the variations of enzyme activity along metabolic pathways and the variations of the flux in a population with biallelic QTL. Two kinds of variations were taken into account, the variation of the average enzyme activity across the loci, and the variation of the activity of each enzyme of the pathway among the individuals of the population. We proposed analytical approximations for the flux mean and variance in the population as well as for the additive and dominance variances of the individual QTL. Monte Carlo simulations based on these approximations showed that an L-shaped distribution of the contributions of individual QTL to the flux variance (R2) is consistently expected in an F2 progeny. This result could partly account for the classically observed L-shaped distribution of QTL effects for quantitative traits. The high correlation we found between R2 value and flux control coefficients variance suggests that such a distribution is an intrinsic property of metabolic pathways due to the summation property of control coefficients.


2008 ◽  
Vol 43 (No. 1) ◽  
pp. 5-9 ◽  
Author(s):  
I. Khan A ◽  
M. Hussain ◽  
S. Rauf ◽  
M. Khan T

Resistance to <i>Cotton leaf curl virus</i> (CLCuV) in three cultivars of cotton was investigated in crosses with a susceptible cultivar using generation mean analysis. No single gene of major effect controlled resistance to Cotton leaf curl virus in the three crosses. The mean number of effective factors controlling resistance in cross LRA-5166 &times; S-12 was estimated to be at least five. Estimates of broad and narrow sense heritability indicate that effects by the environment were larger than those of genetic components. Epistasis was significant in two crosses. Additive gene effects contributed more to resistance than to susceptibility in contrast with dominance gene effect. Reciprocal differences were detected in the cross with LRA-5166. Estimates of genetic gain ranged form low to moderate. Thus, a breeding method that makes use of additive variance should be used because much of the variances for resistance are additive, whereas dominance effects, at least in these crosses, tended to contribute to susceptibility.


2019 ◽  
Vol 55 (No. 3) ◽  
pp. 87-92
Author(s):  
Xiaobing Liu ◽  
Bingjie Tu ◽  
Qiuying Zhang ◽  
Stephen J. Herbert

Pod shattering resistance is a trait acquired by crops in the process of evolution. Manipulation of physiological and molecular processes is fundamental for the improvement of shattering resistance in crops. In this review we discuss several enzymes, key hormones and their possible roles or relationships involved in pod shattering, and highlight responsible genes, quantitative traits loci (QTLs) and their implications for increased pod shattering resistance. Cell wall degrading enzymes, particularly β-glucanases and endopolygalacturonases play an important role in the process of pod dehiscence. It is not clear how and to what extent a specific hormone regulates the dehiscence zone differentiation and the dehiscence process is not clear. Resistance to shattering is highly heritable and is not controlled by a single gene. Several QTLs associated to dehiscence have been identified in crops, while the underlying genetic functions of these QTLs deserve further investigation. Further physiological analyses of the pod wall will help to understand better the pod dehiscence.


Author(s):  
Harinarayan Bind ◽  
Baudh Bharti ◽  
M. K. Pandey ◽  
Sanjeev Kumar ◽  
Vishwanath ◽  
...  

The experimental material for present study consisted of 30 diverse genotypes of oat. Observation were recorded on 11 quantitative traits in oat. High estimates of heritability (broad sense) were obtained for all the characters. The magnitude of PCV as expected was greater than the corresponding GCV for all the characters indicating importance of environment in expression of characters On the basis of result Out of 11 characters studied seeds per panicle, dry matter yield per plant, green fodder yield per plant and harvest index showed high GCV and heritability coupled with high genetic advance as percent of mean which revealed that these four traits might be under control of additive gene effects and therefore they are more reliable for effective selection.


Author(s):  
Shayla Bindra ◽  
R. K. Mittal ◽  
V. K. Sood ◽  
H. K. Chaudhary

Gene effects for 13 characters in four crosses of Vigna mungo were studied by six parameter generation mean model to determine the potential for the improvement of yield components. Scaling tests revealed inadequacy of the additive-dominance model for all the traits indicating the presence of non-allelic interactions. Duplicate gene action was observed for six characters in KUG-216 x HPBU-111, five in KUG-216 x Palampur-93, two in IPU-05-13 x Palampur-93 and one in IPU-05-13 x HPBU-111 and complementary gene action for one character each in KUG-216 x Palampur-93 and IPU-05-13 x HPBU-111 cross. Selection in later generations for duplicate gene action and early generation selection involving intermatings in F2 f or complementary gene action should be adopted for harnessing desirable recombinants.


Genetica ◽  
2006 ◽  
Vol 128 (1-3) ◽  
pp. 471-484 ◽  
Author(s):  
Xiang-Yang Lou ◽  
Mark C. K. Yang

2017 ◽  
Vol 136 (6) ◽  
pp. 939-947 ◽  
Author(s):  
Alper Adak ◽  
Duygu Sari ◽  
Hatice Sari ◽  
Cengiz Toker

2018 ◽  
Vol 3 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Enzo David Ferrari ◽  
Víctor Aníbal Ferreira ◽  
Ezequiel Martín Grassi ◽  
Aurora María Teresita Picca ◽  
Héctor Antonio Paccapelo

Abstract Triticale (x Triticosecale Wittmack) is a cereal used in Argentina as a winter seasonal pasture or feeding grain. Efforts made on breeding have led to varieties with potential grain yield similar or greater than with wheat. The aim of this study was to determine the gene effects, heritability, genetic gain, heterosis and inbreeding depression in various quantitative traits of a cross from contrasting lines of triticale using generation means analysis. The thousand kernel weight was adjusted to a model of additive-dominance, while the rest of the traits exhibited significant epistatic effects: additive x additive (i) for hectoliter weight, additive x dominance (j) for number grains per spike and grain yield per plant. Other traits showed a more complex as inheritance additive x additive (i) and additive x dominance (j) interactions effects for spike length or additive x dominance (j) and dominance x dominance (l) interactions effects for number of spikes per plant and number of spikelets per spike. High values of heritability and genetic gain were also detected for grain yield, spikelets per spike, spike per plant and hectoliter weight. All traits except spike per plant had positive relative mid-parent heterosis, but none resulted in positive heterobeltiosis, therefore this cross is not recommended for obtaining hybrids varieties. Selection in early generations by thousand kernel weight and hectoliter weight would be efficient, while the selection in advanced generations where segregation is minimal would be recommended for the remaining traits.


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