Genotype–nitrogen interactions in full-sib seedlings of black spruce

1985 ◽  
Vol 15 (6) ◽  
pp. 1031-1038 ◽  
Author(s):  
T. J. Mullin
Keyword(s):  
Genetic Variation ◽  
Combining Ability ◽  
Genetic Variance ◽  
Black Spruce ◽  
Height Growth ◽  
General Combining Ability ◽  
Narrow Sense ◽  
Components Of Variance ◽  
Nitrogen Fertility ◽  
Growth Characters

Genotype–environment interactions were investigated in 40 full-sib black spruce (Piceamariana (Mill.) B.S.P.) families grown in a greenhouse for 25 weeks under three levels of nitrogen fertility. Large general combining ability components of variance indicated that much of the genetic variance was additive. Heritability estimates were also high, with narrow-sense heritabilities of 0.35 for 25-week height growth and 0.15 for ovendry weight. Specific combining ability, reciprocal, and maternal effects were negligible for all but very early seed and growth characters. Statistically significant family × nitrogen interaction components were detected for all growth variables. Stability analysis using regression suggested that these interactions were due more to differences in degree of expression of genetic variation than to extreme changes in rank. Generally, the families that ranked in the top 10% at the highest nitrogen level were above average at all other levels.

scholarly journals Performance of testers with different genetic structure for evaluation of maize inbred lines

2012 ◽  
Vol 42 (5) ◽  
pp. 770-776 ◽  
Author(s):  
Lauro José Moreira Guimarães ◽  
Glauco Vieira Miranda ◽  
Rodrigo Oliveira DeLima ◽  
Ciro Maia ◽  
Lucimar Rodrigues de Oliveira ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Combining Ability ◽  
Genetic Variance ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Genetic Base ◽  
Maize Inbred Lines ◽  
Single Cross ◽  
Single Cross Hybrids

The objective of this study was to evaluate four maize testers for identification of superior inbreed lines in testcross. The four testers evaluated are cultivars with narrow or wide genetic base (single-cross hybrids and open pollinated varieties) and two kernel types (flint or dent). SynD and SynF testers are open pollinated varieties with dent and flint kernels, respectively, and FSH and DSH testers are single-cross hybrids with flint and dent kernels, respectively. SynD tester showed the biggest genetic variance among the maize inbreed lines in crosses. The effects of general combining ability (GCA) for lines and specific combining ability (SCA) for lines x testers were significant, whereas GCA effects for testers were not significant. SynD and SynF testers identified the largest number of lines with higher GCA. The DSH and FSH testers showed suitable to identify lines with high SCA. It was concluded that SynD and SynF testers are adequate to identify inbreed lines with high GCA effects, and it's possible to identify new lines with high heterotic potential in each one of the four testers.

GENOTYPE × ENVIRONMENT INTERACTIONS IN SMOOTH BROMEGRASS. I. YIELD

1979 ◽  
Vol 21 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Wai-Koon Tan ◽  
Geok-Yong Tan ◽  
P. D. Walton
Keyword(s):  
Genetic Variation ◽  
Analysis Of Variance ◽  
Combining Ability ◽  
Significant Variation ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Bromus Inermis ◽  
Smooth Bromegrass ◽  
Combining Ability Analysis ◽  
Half Diallel

Twenty-one progenies and the parents of a 7 × 7 half diallel cross of smooth bromegrass (Bromus inermis Leyss.) were evaluated at four locations in Alberta in each of two years, for genetic variation and genetic by environment interactions in the expression of their yield potentials. Years, locations and their interactions were highly significant in the combined analysis of variance. Combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were both important in the expression of yield, including spring, fall and annual yield, whereas GCA was more important than SCA for yield per area. Although the genotype × environment interactions were all highly significant, variation accounted for by combining ability effects was generally higher than the interaction effects of GCA and SCA respectively, with environments. High average GCA effects for spring, fall and annual yield were demonstrated for the clones UA5, UA9 and B42. These together with the high average SCA effects suggested that the three clones could be included in a synthetic to develop high yielding cultivars. The results suggested that recurrent selections involving multi-location and multi-year testing seems necessary in breeding for high yielding bromegrass cultivars in Alberta.

GENERAL AND SPECIFIC COMBINING ABILITY IN SEVEN INBRED STRAWBERRY LINES

1968 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Lewis E. Aalders ◽  
Donald L. Craig
Keyword(s):  
Genetic Variation ◽  
Powdery Mildew ◽  
Combining Ability ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Additive Genetic Variation

Seedlings of a diallel cross of seven strawberry inbreds omitting reciprocals were fruited in matted rows. Per acre fruit yields were comparable with leading cultivars, but berry appearance and quality of the hybrids were poor. Differences in resistance to powdery mildew reflected the values of the cultivars from which the inbreds were derived.All four characters studied showed significant general combining ability values, and three of the four showed significant specific combining ability values. These results are consistent with previous findings of considerable amounts of non-additive genetic variation in the strawberry.

Genetic analysis of epicuticular wax production in alfalfa

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 896-899 ◽  
Author(s):  
P. G. Jefferson ◽  
D. A. Johnson ◽  
M. D. Rumbaugh
Keyword(s):  
Medicago Sativa ◽  
Drought Resistance ◽  
Combining Ability ◽  
Genetic Material ◽  
General Combining Ability ◽  
Epicuticular Wax ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Plant Nursery ◽  
Wax Production

Epicuticular wax production increases in drought-stressed plants and has been identified as a potential drought resistance selection criterion. The objective of the present study was to determine the genetic variances and narrow-sense heritability of epicuticular wax production in alfalfa (Medicago sativa L.). These parameters were determined from a 14 parent diallel cross that included all possible progeny combinations. Cross progenies, selfed progenies, and reciprocal crosses were grown in a space-plant nursery at Logan, Utah. Epicuticular wax was determined gravimetrically after washing 100 cm2 of leaves (2.5 g) in carbon tetrachloride. General combining ability was significant (P < 0.05), and estimated heritability was 35% from one harvest in 1985. Specific combining ability and reciprocal effects were not significant. A subset of six parents and their progenies were sampled for two harvests in 1986. The general combining ability by harvest interaction was significant (P < 0.01) for epicuticular wax production, indicating that the true narrow-sense heritability may be lower than 35%. The range in epicuticular wax production among harvests was as great as among progenies. A greater diversity of genetic material would be useful in a selection program for epicuticular wax production in alfalfa.Key words: Medicago sativa, heritability, drought resistance, genetic variability, diallel analysis.

scholarly journals Quantitative Genetic Analysis of Fruit Quality in Pear

1990 ◽  
Vol 115 (5) ◽  
pp. 829-834 ◽  
Author(s):  
R.L. Bell ◽  
Jules Janick
Keyword(s):  
Fruit Quality ◽  
Combining Ability ◽  
Genetic Improvement ◽  
Quality Index ◽  
Quality Characteristics ◽  
General Combining Ability ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Quantitative Genetic ◽  
Selection Of

Narrow-sense heritability estimates were computed for five fruit quality characteristics and their weighted total index. Grit content and skin russeting were moderately heritable traits, while flesh texture, flavor, appearance, and the weighted total score were of relatively low heritability. Within sub-populations of crosses, defined by the species ancestry of the parents, the relative magnitudes of heritabilities for each trait varied, but were in general agreement with those for the entire population. The general combining ability variances were 4.5 to 12.0 times those for specific combining ability, although both were statistically significant for all traits and the weighted quality index. The species ancestry of a parent had no effect on its general combining ability rank. While selection of individual seedlings on the basis of their own phenotype will result in genetic improvement for grit and russet, selection based on a combination of full-sib family means and individual phenotypes is recommended for flavor, texture, appearance, and overall fruit quality.

Thrips (Thysanoptera: Thripidae) Tolerance in Cotton: Sources and Heritability

1997 ◽  
Vol 32 (4) ◽  
pp. 460-471 ◽  
Author(s):  
Daryl T. Bowman ◽  
Jack C. McCarty
Keyword(s):  
North Carolina ◽  
Gossypium Hirsutum ◽  
Combining Ability ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
General Combining Ability ◽  
Sources Of Resistance ◽  
Gossypium Hirsutum L ◽  
F2 Generation ◽  
F1 Generation

Thrips (Thysanoptera: Thripidae) resistance or tolerance in cotton, Gossypium hirsutum L., is often associated with extreme pubescence. This is undesirable because hairy (pubescent) plants tend to have more trash in harvested lint which reduces the price received by growers. Two other possible sources of resistance include gossypol and thick lower epidermal cells, the latter has been found in G. barbadense L. Five G. barbadense genotypes were mated in a North Carolina Design II to 4 upland cultivars to evaluate combining ability. In addition, 90 converted racestocks were screened for tolerance to thrips. Experiments were designed to evaluate tolerance or resistance by comparing plots with and without thrips. Two G. barbadense parents had tolerance to thrips while two upland cultivars also exhibited tolerance. In the F1 generation, general combining ability was significant for thrips damage ratings among the G. barbadense parents. In the F2 generation, all characters exhibited specific combining ability. Thus, non-additive genetic variance predominates measures of thrips tolerance.

A diallel cross in black spruce

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 180-186 ◽  
Author(s):  
T. J. B. Boyle
Keyword(s):  
Combining Ability ◽  
Variance Components ◽  
Genetic Variance ◽  
Black Spruce ◽  
Diallel Cross ◽  
Specific Combining Ability ◽  
Environment Interaction ◽  
Forest Genetics ◽  
Data Set ◽  
Dominance Genetic Variance

A complete 7 × 7 diallel of black spruce (Picea mariana (Mill.) B.S.P.), without selfs, planted in three locations, was measured for height growth at several ages. Analysis using Griffing's method 3, model II, demonstrated that general combining ability (GCA) was the dominant genetic component of variation, although specific combining ability (SCA) appeared to be proportionately increasing in importance with age. When data from all locations were combined, the GCA × environment interaction proved to be highly significant. If the trend of increasing proportional importance of SCA continues, existing improvement strategies exploiting only GCA may need to be radically altered. Greater genetic gain would result from crosses among a few clones of high specific combining ability. Whatever approach is used, it appears likely that genotypes will have to be carefully matched to sites. Imbalance in the data set appeared to invalidate F-tests. As a result of heterozygosity in the parents and the likely presence of epistasis and linkage disequilibrium, the interpretation of GCA and SCA variance components in terms of additive and dominance genetic variance cannot be made. Key words: diallel cross, combining ability, black spruce, forest genetics.

scholarly journals Paper Birch and European White Birch Vary in Growth and Resistance to Bronze Birch Borer

1991 ◽  
Vol 116 (3) ◽  
pp. 580-584 ◽  
Author(s):  
Raymond O. Miller ◽  
Paul D. Bloese ◽  
James W. Hanover ◽  
Robert A. Haack
Keyword(s):  
Genetic Variation ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Species Variation ◽  
Betula Papyrifera ◽  
Narrow Sense ◽  
White Birch ◽  
Northeastern North America ◽  
Bronze Birch Borer ◽  
Paper Birch

A test of Michigan half-sib progeny of paper birch (Betula papyrifera Marsh.) and European white birch (B. pendula Roth.) was conducted in Michigan to examine species variation in growth, bark color, and resistance to bronze birch borer (Agrilus anxius Gory). Paper birch was superior to European white birch in height and borer resistance at age 12 years from seed. Families of paper birch were identified that grew exceptionally well, had developed white bark within 6 years, and exhibited borer resistance. The magnitude of additive genetic variance and narrow-sense family heritability estimates for paper birch indicated that sufficient genetic variation and inheritance exist to support selection and breeding for height. Paper birch may be an acceptable substitute for European white birch as a landscape species in northeastern North America.

scholarly journals Breeding and genetic peculiarities of spring barley 1000 kernel weight under conditions of the central part of the Ukrainian Forest-Steppe

2021 ◽  
Vol 17 (3) ◽  
pp. 183-192
Author(s):  
V. M. Hudzenko ◽  
T. P. Polishchuk ◽  
A. A. Lysenko ◽  
L. V. Khudolii ◽  
A. I. Babenko
Keyword(s):  
Genetic Variation ◽  
Combining Ability ◽  
Spring Barley ◽  
General Combining Ability ◽  
Kernel Weight ◽  
Forest Steppe ◽  
Diallel Crossing ◽  
Growing Conditions ◽  
Negative Dominance ◽  
Final Selection

Purpose. To reveal the breeding and genetic peculiarities for spring barley 1000 kernel weight and to identify genetic sources for breeding under conditions of the central part of the Forest-Steppe of Ukraine. Methods. Investigations were carried out at the V. M. Remeslo Myronivka Institute of Wheat of the NAAS of Ukraine. Spring barley F1 of two comp­lete (6 ´ 6) diallel crossing schemes was investigated. The first scheme included modern both domestic and foreign spring barley malting varieties (‘MIP Tytul’, ‘Avhur’, ‘Datcha’, ‘Quench’, ‘Gladys’, ‘Beatrix’), the second – classic covered awned (‘MIP Myroslav’, ‘Sebastian’), awnless (‘Kozyr’, ‘Vitrazh’) and naked (‘Condor’, ‘CDC Rattan’) varieties. Results. Various types of inheritance of 1000 kernel weight were revealed, with the exception of negative dominance. The proportion of combinations with corresponding values ​​of the degree of phenotypic dominance varied depending on the genotypes involved in the crossing and the years of testing. In both crossing schemes, both in 2019 and in 2020, positive overdominance was found in most combinations. The grea­test number of combinations with the manifestation of hete­rosis under different growing conditions was noted when varieties ‘Gladys’ and ‘MIP Myroslav’ were used in crossing. According to the parameters of genetic variation, it was revealed that the trait was determined mainly by the additive-dominant system. The dominance was aimed at increasing the 1000 kernel weight. Only in the second crossing scheme in 2019 the value of the directional dominance indicator was unreliable. In the loci, incomplete dominance in 2019 and over-dominance in 2020 were revealed. Reliably high effects of the general combining ability in both years were noted for varieties ‘Datcha’, ‘Gladys’, ‘MIP Myroslav’, ‘Kozyr’ and ‘Vitrazh’. Conclusions. The revealed breeding and genetic peculiarities indicate that for the overwhelming majority of created hybrid combinations will be required the final selection in later generations, when the dominant alleles are homozygous. Spring barley awned varieties ‘Gladys’, ‘MIP Myroslav’ and ‘Datcha’, as well as awnless varieties ‘Kozyr’ and ‘Vitrage’ can be used as effective genetic sources for increa­sing the 1000 kernel weight

scholarly journals Genetic Variation and Selection for Carotene Content in Carrots

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 821E-821
Author(s):  
Philipp Simon
Keyword(s):  
Genetic Variation ◽  
Combining Ability ◽  
General Combining Ability ◽  
Mass Selection ◽  
Realized Heritability ◽  
Response To Selection ◽  
Carotene Content ◽  
Selection For ◽  
Variation And Selection ◽  
Made In

A six-parent diallel which included carrot inbreds with a range of carotene content from 80 to 490 ppm was evaluated over 2 years. General combining ability accounted for most of the variation observed. Phenotypic mass selection was exercised for high carotene content in three carrot populations. Response to selection continued to be high in one population, HCM, after 11 cycles of selection. In contrast, after three generations of selection, little progress was able to be made in a population derived from primarily Nantes-type open-pollinated cultivars. Realized heritability estimates varied from 15% to 49%. Environment contributed significantly to variation in carotene content.

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