GENE EFFECTS IN CORN (ZEA MAYS L.): I. SEPARATION AND RELATIVE IMPORTANCE OF GENE EFFECTS FOR YIELD

1962 ◽  
Vol 42 (2) ◽  
pp. 339-348 ◽  
Author(s):  
E. E. Gamble
Keyword(s):  
Zea Mays ◽  
Genetic Variation ◽  
Zea Mays L ◽  
Inbred Lines ◽  
Relative Importance ◽  
Gene Effects ◽  
Yield Performance ◽  
Population Means ◽  
Additive Gene Effects ◽  
Additive Gene

A procedure is outlined for the separation, into six parameters, of gene effects affecting genetic variation of a quantitative trait. These parameters represent mean effects, additive and dominance gene effects, and the three types of digenic epistatic effects. Estimates of the parameters are obtained using the population means of two inbred lines, their cross, and descendants due to subsequent selfing and crossing. The relative importance of the different gene effects can be evaluated from the magnitude and significance of the estimates.Population means of six inbred lines of corn, and all possible F1, F2, P1F1, and P2F1 crosses among them, were used to obtain estimates of the various gene effects for yield of shelled corn. Mean yield performance of the populations was obtained from four experiments grown at two locations in each of 2 years.With regard to the 15 crosses, the estimates of gene effects indicate that the dominance gene effects were quite important in the inheritance of yield. Estimates of additive gene effects were of low magnitude and many were non-significant. Epistatic gene effects were considered to be more important than additive gene effects in the inheritance of yield in the crosses studied. The additive × additive and additive × dominance gene effects were relatively more important than the dominance × dominance effects.

GENE EFFECTS IN CORN (ZEA MAYS L.): III. RELATIVE STABILITY OF THE GENE EFFECTS IN DIFFERENT ENVIRONMENTS

1962 ◽  
Vol 42 (4) ◽  
pp. 628-634 ◽  
Author(s):  
Edwin E. Gamble
Keyword(s):  
Zea Mays ◽  
Relative Stability ◽  
Seed Weight ◽  
Zea Mays L ◽  
Inbred Lines ◽  
Minor Importance ◽  
Gene Effects ◽  
Population Means ◽  
Additive Gene ◽  
The Cross

Six inbred lines of corn and their F1’s, F2’s, and backcrosses were tested at two locations in each of 2 years. The population means obtained were used to estimate additive, dominance, additive × additive, additive × dominance, and dominance × dominance gene effects for six quantitative attributes.Variance components of cross × environment interactions indicated the presence of major interactions of gene effects with environments. The cross × year interactions were of major importance but the cross × location interactions were of minor importance. Additive gene effects appeared to be the most constant over environments followed by additive × dominance gene effects. The remaining types of gene effects indicated very little stability over environments for most of the attributes studied. Estimates of gene effects were most constant over environments for ear diameter in corn while yield, plant height, and seed weight showed little or no stability of the estimates of the gene effects.

GENE EFFECTS IN CORN (ZEA MAYS L.): II. RELATIVE IMPORTANCE OF GENE EFFECTS FOR PLANT HEIGHT AND CERTAIN COMPONENT ATTRIBUTES OF YIELD

1962 ◽  
Vol 42 (2) ◽  
pp. 349-358 ◽  
Author(s):  
E. E. Gamble
Keyword(s):  
Plant Height ◽  
Seed Weight ◽  
Zea Mays L ◽  
Inbred Lines ◽  
Relative Importance ◽  
Additive Effects ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene ◽  
Kernel Row Number

Estimates of mean effects, additive, dominance, additive × additive, additive × dominance, and dominance × dominance gene effects were obtained for 15 crosses from 6 inbred lines of corn for each of the following attributes: plant height, kernel row number, ear length, ear diameter, and seed weight.All the gene effects were found to contribute to inheritance of the attributes in the crosses studied. However, not all gene effects are present in all crosses. Mean effects were the most important contributors to the inheritance of the attributes. Of the gene effects, the dominance gene effects were the most important contributors to the inheritance of the attributes except for kernel row number. Additive, dominance and epistatic gene effects appear to contribute more or less equally to the inheritance of kernel row number. Additive gene effects were more important for these attributes than for yield. They were relatively more important for kernel row number, ear diameter, and seed weight than for plant height and ear length.Epistatic gene effects were relatively more important than additive gene effects but less important than dominance gene effects for the material studied. For the attributes studied the additive × dominance and dominance × dominance gene effects were somewhat more important contributors to inheritance than the additive × additive effects.

Estimating the heritability of butterfat production

1961 ◽  
Vol 57 (3) ◽  
pp. 289-294 ◽  
Author(s):  
S. R. Searle
Keyword(s):  
Genetic Variation ◽  
New Zealand ◽  
Dairy Cows ◽  
Total Variance ◽  
Additive Effects ◽  
Narrow Sense ◽  
Sampling Errors ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene

Part of the variation among butterfat yields in dairy cows arises from genetic differences among the animals. The proportion which this bears to the total variance is known as heritability. In the ‘narrow’ sense it is defined (Lush, 1940), as the proportion of the total variance that is due to additive gene effects; the ‘broad’ sense definition includes genetic variation arising from non-additive gene effects as well as that due to additive effects. Since related animals have a proportion of their genes in common the covariance among their production records can be used for estimating genetic variation and hence heritability. This paper discusses three groups of related animals most frequently used for this purpose, twins, daughter-dam pairs and paternal half-sibs, and presents the results of analysing production records of artificially bred heifers in New Zealand, including evidence of the magnitude of the sampling errors of the heritability estimates.

Genetics of weather fleck in Nicotiana tabacum

1983 ◽  
Vol 25 (2) ◽  
pp. 97-100 ◽  
Author(s):  
M. K. Aycock Jr.
Keyword(s):  
Nicotiana Tabacum ◽  
Recurrent Selection ◽  
Doubled Haploids ◽  
Reciprocal Recurrent Selection ◽  
Gene Effects ◽  
Population Means ◽  
Additive Gene Effects ◽  
Nicotiana Tabacum L ◽  
Resistant Lines ◽  
Additive Gene

A 2-year study was conducted to investigate additive, dominance, and epistatic gene effects for weather fleck in Maryland tobacco (Nicotiana tabacum L.). P1, P2, F1, F2, P1F1, and P2F1 population means from each of seven crosses were used to estimate gene effects. In general, additive gene effects were more important in the inheritance of weather fleck than dominance or epistatic effects; however, in three of the seven crosses dominance and (or) epistatic gene effects were important. Adequate additive gene effects were present in five of the seven crosses to allow considerable progress towards selection of more weather fleck resistant lines. In two families, because of significant epistatic gene effects, the development of weather fleck resistant lines could be accomplished by producing doubled haploids from desirable F1 plants or by using a reciprocal recurrent selection program.

scholarly journals Habilidad combinatoria de 8 líneas élites dominicanas de maíz (Zea Mays L.)

2016 ◽  
Vol 4 ◽  
pp. 65
Author(s):  
José Richard Ortiz ◽  
Pedro Comalat Rodes
Keyword(s):  
Zea Mays ◽  
Genetic Variation ◽  
Grain Yield ◽  
Combining Ability ◽  
Zea Mays L ◽  
Inbred Lines ◽  
Additive Genetic Variation

Twenty eight inter-crosses from a diallel set of 8 Dominican inbred lines of maize were evaluated in 1990. The specific objectives were to determine general(gca) and specific (SCA) combining ability and to predict the best two and three-way hybrids. The inheritance of yield was determined by diaIlel analysis. General and specific (sca) combining ability and specific mean squares were statistically significant in yield, being the additive genetic variation much larger than the non additive variation. The parental T66 and NO3 showed the highest gca values and DK12xT66 (9.02 t/ha),NO2xNO3 (8.57t/ha) and DK12xT66 (8.36 t/ha) the best  sca values. The results partially agree with previous studies. The best three and two way hybrids predictions were (NO3xT66)x NO3 and(NO2xT66) (NO3xDK14) with grain yield of 8.80 and 8.30 t/ha.

scholarly journals Breeding oilseed rape for pod shattering resistance

2000 ◽  
Vol 135 (4) ◽  
pp. 347-359 ◽  
Author(s):  
C. L. MORGAN ◽  
Z. L. LADBROOKE ◽  
D. M. BRUCE ◽  
R. CHILD ◽  
A. E. ARTHUR
Keyword(s):  
Genetic Variation ◽  
Agronomic Traits ◽  
Dominant Gene ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Pod Shattering ◽  
Additive Gene ◽  
Pod Shatter ◽  
Pod Wall ◽  
Pod Dehiscence

The genetic control of pod dehiscence was studied through the production, field trial and subsequent analysis of a full diallel involving seven parents selected for high and low resistance to pod shattering. Additive gene effects were most significant among the measures of pod shattering resistance with only minor contributions from non-additive gene effects. Genetic variation in measures of the stiffness of the pod wall were, however, determined by dominant gene effects. Genes for increased pod shattering resistance acted recessively. All characters showed high levels of heritability. Correlations among pod shatter resistance characters and other pod, raceme and plant characters were low suggesting that resistance is likely to be independent of other important agronomic traits.

scholarly journals Combining Ability of Quality Protein Maize Inbred Lines for Yield and Morpho-Agronomic Traits under Optimum as Well as Combined Drought and Heat-Stressed Conditions

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 184 ◽  
Author(s):  
Nyasha E. Chiuta ◽  
Charles S. Mutengwa
Keyword(s):  
Heat Stress ◽  
Combining Ability ◽  
Agronomic Traits ◽  
Inbred Lines ◽  
Sub Saharan Africa ◽  
Optimum Conditions ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene ◽  
Drought And Heat Stress

Drought and heat stress have perceptibly become major maize (Zea mays L.) yield reducing factors in Sub-Saharan Africa. As such, the objectives of this study were to: (i) determine the type of gene action conditioning tolerance to combined drought and heat stress (CDHS), and (ii) identify inbred lines with good combining ability for yield and other morpho-agronomic traits under CDHS. Twenty-four single cross hybrids (SCHs) obtained from crossing 10 inbred lines in a 4 × 6 North Carolina Design II, and a drought-tolerant check, were evaluated under CDHS and optimum conditions in the field. The experiment was laid out in a 5 × 5 alpha lattice incomplete block design, replicated three times. Additive gene effects influenced all the traits under CDHS except grain yield, which was influenced by non-additive gene effects. A preponderance of additive genetic effects was observed for all traits recorded under optimum conditions. Inbred lines L30, L6, L5, L17 and L2 showed good combining ability for yield under CDHS, indicating that they could be good parental lines in hybridization programs. Based on the results, SCHs L2*30, L6*13 and L5*18 exhibited high specific combining ability (SCA) effects for yield under CDHS. These hybrids are recommended for further multi-locational evaluation to determine the stability of their performance.

scholarly journals Effects of total and variances specific combining ability of hemp inbred lines and varieties in topcross systems

1970 ◽  
Vol 21 ◽  
pp. 62-67
Author(s):  
S. V. Mishchenko
Keyword(s):  
Combining Ability ◽  
Cannabis Sativa ◽  
Inbred Lines ◽  
Specific Combining Ability ◽  
Gene Effects ◽  
Study Methods ◽  
Additive Gene Effects ◽  
Additive Gene

Aim. Determination of combining ability of monoecious hemp (Cannabis sativa L.) inbred lines and varieties by quantitative breeding signs of plants are the aims of our study. Methods. The study was conducted in 2014–2016 in the Institute of Bast Crops of NAAS. The effects of total combining ability and specific combining ability variances investigated in the full topcross systems by the method P.P. Lytun and N.V. Proskurnyn (1992). Results. Inbred lines and varieties of hemp were significantly differentiated by the total combining ability effects and specific combining ability variances. Conclusions. Line×variety crossing Central-Russian eco-geographical type and Southern eco-geographical type of hemp was recommended for productive combination breeding. Keywords: hemp, variety, topcross, total combining ability and specific combining ability, additive gene effects and non-additive gene effects.

scholarly journals Popping volume and grain yield in diallel set of popcorn inbred lines

Genetika ◽  
2008 ◽  
Vol 40 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Zorica Pajic ◽  
Uros Eric ◽  
Jelena Srdic ◽  
Snezana Mladenovic-Drinic ◽  
Milomir Filipovic
Keyword(s):  
Grain Yield ◽  
Analysis Of Variance ◽  
Combining Ability ◽  
Inbred Lines ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Satisfactory Yield ◽  
Genetic Components ◽  
Additive Gene ◽  
Superior Genotypes

Popping volume and yield are traits caused by several heredity factors. It is difficult to obtain superior genotypes for both traits but it is possible to develop genotypes with good popping volume and satisfactory yield. The hybrid ZPPL2 x ZPPL5 was superior in yield, heterosis and SCA for both yield and popping volume. As inbred ZPPL4 in all combinations has a good value for popping volume could be concluded that this inbred may be used as parent in further crosses. Analysis of variance of the combining ability indicating significant SCA effect for grain yield, and significant both GCA and SCA effects for popping volume. Therefore it can be stated that yield is influenced by non-additive and popping volume by both additive and non- additive gene effects. Analysis of variance of genetic components for popping volume indicates that the additive as well as dominant components significantly affected the inheritance of this trait in popcorn. The objective of this study was to evaluate heteorsis and combing ability for grain yield and popping volume in dialalel set of six maize inbred lines.

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