Genetic parameters and provenenance variation of Pinus caribaea var. hondurensis in 48 international trials

2001 ◽  
Vol 31 (3) ◽  
pp. 496-511 ◽  
Author(s):  
G R Hodge ◽  
W S Dvorak
Keyword(s):  
First Generation ◽  
Genetic Parameters ◽  
Volume Growth ◽  
Environment Interaction ◽  
Pinus Caribaea ◽  
Genotype Environment Interaction ◽  
The Mean ◽  
Selection For ◽  
Similar Growth ◽  
Better Than

A total of 23 provenances or sources of Pinus caribaea var. hondurensis (Sénécl) Barr. et Golf. were tested in 48 provenance–progeny trials in Colombia, Brazil, and Venezuela. In Brazil and Venezuela, 8-year heights were approximately 12 m, while in Colombia, mean 8-year height was less than 8 m. The growth rates of the unimproved material correspond approximately to volumes of 14–15 m3·ha–1·year–1 of wood on sites in Brazil and Venezuela, and 4–5 m3·ha–1·year–1 in Colombia. Provenances had similar growth rankings in the different countries, with a type-B provenance correlation of 0.63. The best native provenances were Limón and Guanaja, Honduras. Improved first-generation sources from Queensland, Australia and Zululand, South Africa, were 5–12% better than the mean of the unimproved provenances, depending on country where planted. Mean single-site heritability for volume growth is approximately 0.18. Potential genetic gain for volume at 8 years from selection within provenance is around 30%. Foxtailing is also under moderate genetic control with heritability around 0.15. Genotype × environment interaction for volume growth is generally higher for tests located in different countries than in the same countries. Selection for age-8 volume using age-5 data would be 93% as effective as selection at age 8.

scholarly journals Genotype × environment interaction in Tribolium castaneum

1964 ◽  
Vol 5 (3) ◽  
pp. 335-340 ◽  
Author(s):  
J. F. Kidwell ◽  
A. E. Freeman ◽  
L. H. Haverland ◽  
G. M. H. Rolfes
Keyword(s):  
Relative Humidity ◽  
Tribolium Castaneum ◽  
Total Variance ◽  
Direct Selection ◽  
Environment Interaction ◽  
Breeding Values ◽  
Genotype Environment Interaction ◽  
The Mean ◽  
Selection For ◽  
C 30

An experiment was conducted with the flour beetle, Tribolium castaneum to investigate genotype-environment interaction. Ninety-two matings of one male and three females were made at random from a large panmictic population. The females were transferred to individual containers after 4 days. Six daughters were randomly selected from each sire–dam pair and individually mated to unrelated males. Three of the six were placed in an incubator (33·3°C., 45% relative humidity) and three in a cabinet at room conditions (22·2–26·7°C., 30–35% relative humidity) and allowed to produce eggs during a 3-day period. Progeny were counted as pupae and larvae. The traits studied were number of pupae and number of pupae plus number of larvae. A transformation to (X +1)½ was required. A conventional least-squares model was employed, and a large environmental effect was observed. In the incubator the mean number of pupae was 13·4 and of pupae + larvae was 20·1 while the corresponding figures for room conditions were 3·3 and 9·2. Genotype-environment interaction accounted for 3·7 to 6·7% of the total variance for (pupae + 1)½ and 2·1 to 8·3% for (pupae + larvae+ 1)½. Heritability of the traits was essentially the same in both environments. The interaction was due to an increasing difference between environments in production associated with increasing breeding values of the sire, and to small changes in rank of breeding values on the two environments. As a result of the interaction, selection in one environment for production on the other would be expected to be only 71 to 72% as effective as direct selection for (pupae + 1)½ and 62 to 86% for (pupae + larvae + 1)½ even though the fraction of the total variance attributed to genotype-environmental interaction was less than 10%.

scholarly journals Studies in Artificial Selection of Quantitative Characters II. Selection for Body Weight in Drosophila Melanogaster

1963 ◽  
Vol 16 (2) ◽  
pp. 516 ◽  
Author(s):  
BL Sheldon
Keyword(s):  
Body Weight ◽  
Genetic Variability ◽  
Genetic Parameters ◽  
Random Mating ◽  
Environment Interaction ◽  
Genotype Environment Interaction ◽  
Quantitative Characters ◽  
Diallel Crossing ◽  
Selection For ◽  
Selection Of

The method of diallel crossing within a population with random mating was used to estimate genetic parameters for body weight in an Oregon-RO laboratory stock. This showed an absence of additive genetic variability, a high proportion of non-additive genetic variability, and considerable genotype-environment interaction.

Genetic parameters and genotype–environment interactions of Chinese fir (Cunninghamia lanceolata) in Fujian Province

2014 ◽  
Vol 44 (6) ◽  
pp. 582-592 ◽  
Author(s):  
Liming Bian ◽  
Jisen Shi ◽  
Renhua Zheng ◽  
Jinhui Chen ◽  
Harry X. Wu
Keyword(s):  
Genetic Parameters ◽  
Breeding Strategy ◽  
Chinese Fir ◽  
Breeding Program ◽  
Cunninghamia Lanceolata ◽  
Environment Interaction ◽  
Fujian Province ◽  
The Third ◽  
Genotype Environment Interaction ◽  
Sib Families

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is the most commercially important conifer in China, and the Nanjing Forestry University – Fujian Province Chinese fir Cooperation (NJFU – Fujian Cooperation) breeding program has advanced it into the third cycle of selection and breeding. In this paper, we estimated genetic parameters from four sites for 80 half-sib families and summarized previous estimates of genetic parameters in Chinese fir with an objective to propose optimal breeding strategy. Heritability averaged 0.20 and 0.14 for height and diameter at breast height (DBH), respectively, for the four sites. A significant genotype–environment interaction (G × E) for growth was also observed among the four sites, with the greatest interactions between a marginal site and the three central sites in the Fujian Province Chinese fir plantation region. The average estimated type-B genetic correlation between the marginal site and the three central sites was 0.08 for height and –0.09 for DBH. However, the highly productive families were among the most stable across the four sites. The results from this study in combination with summarized genetic parameters from literature were used to discuss and propose an optimal breeding strategy for the third generation of the breeding program for Chinese firs in Fujian Province.

GROUPING LOCATIONS FOR EFFICIENT CASSAVA EVALUATION IN MALAWI

2003 ◽  
Vol 39 (2) ◽  
pp. 167-179 ◽  
Author(s):  
J. MKUMBIRA ◽  
N. M. MAHUNGU ◽  
U. GULLBERG
Keyword(s):  
Environmental Heterogeneity ◽  
Principal Component ◽  
Environment Interaction ◽  
Scatter Plot ◽  
Genotype Environment Interaction ◽  
Breeding Zone ◽  
Adverse Environmental Conditions ◽  
The Tropics ◽  
Pair Wise Comparison ◽  
Better Than

Cassava, a crop widely adapted in the tropics, has the important attribute of withstanding adverse environmental conditions better than do many other staple crops. The performance of an individual genotype, however, is influenced by the environment in which it grows. In Malawi, the heterogeneity of agro-ecologies requires the cumbersome and costly assessment of new cassava genotypes at many sites. This study was conducted, therefore, to test the feasibility of selecting only a few locations for cassava evaluation that would be representative of all the agro-ecologies in which cassava is grown in Malawi. Enormous environmental effects, largely contributed by the interaction between season and location, were manifested. Genotype×environment interaction, due largely to a third level interaction (genotype×season×location), was highly significant for all the traits studied. A principal component analysis scatter plot showed no particular grouping of environments, but a pair-wise comparison showed that some of the locations had limited genotype×environment interaction, indicating that it would be sufficient to use one of these sites for evaluating these traits. The value of the residual was often large, probably as an effect of environmental heterogeneity in the test sites. The authors conclude that cassava genetic improvement will continue to be slow if Malawi is used as a single breeding zone. They recommend a much finer grouping of the locations and the use of smaller plot sizes to allow more clones to be tested at more sites for the same cost. Locations may be selected for intensive cassava breeding work from those that give the best discrimination between genotypes while having insignificant genotype×environment interactions in a relatively large number of environments.

scholarly journals Genetic variability for girth growth and rubber yield in Hevea brasiliensis

2006 ◽  
Vol 63 (3) ◽  
pp. 246-254 ◽  
Author(s):  
Paulo de Souza Gonçalves ◽  
Marcelo de Almeida Silva ◽  
Ligia Regina Lima Gouvêa ◽  
Erivaldo José Scaloppi Junior
Keyword(s):  
Hevea Brasiliensis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Basic Knowledge ◽  
Environment Interaction ◽  
Genetic Characteristics ◽  
Genotype Environment Interaction ◽  
Genetic And Phenotypic Correlations ◽  
High Heritability ◽  
Selection Intensities

Basic knowledge of genetic characteristics of populations is necessary to conduct effective breeding and selection. The objective of this paper is describing the genetic variation of rubber yield and the correlation with other traits, and estimating the genetic parameters for girth growth and total number of latex vessels. Sixty seven clones of Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. were tested at five sites during 10 years. Characters girth growth at panel opening and rubber yield, showed broad sense heritability on plot mean level, from 0.32 to 0.66 and 0.59 to 0.92, respectively. Predicted genetic gains equal to 0.73 cm and 0.79 g increase respectively on girth and yield in the opening panel and mature phases seems realistic, even with moderate selection intensities. Genetic correlations with rubber yield, bark thickness and total number of latex vessels were very large, and almost no genotype-environment interaction was present for girth growth. High genotype-environment interaction was present for rubber yield with genetic and phenotypic correlations across the sites, ranging from 0.64 to 0.92 (genetic) and 0.63 to 0.89 (phenotypic). Total number of latex vessels rings had a high heritability, ranging from 20.0% to 64.0% in the sites E and B, respectively.

scholarly journals Genotype-environment interaction, genetic trends, and performance dissimilarity of Nellore herds raised in three different environmental gradients

2018 ◽  
Vol 39 (1) ◽  
pp. 349
Author(s):  
Julio Cesar de Souza ◽  
Fabio Rafael Leão Fialho ◽  
Marcos Paulo Gonçalves Rezende ◽  
Carlos Henrique Cavallari Machado ◽  
Mariana Pereira Alencar ◽  
...  
Keyword(s):  
Weight Gain ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Environmental Gradients ◽  
Superior Performance ◽  
Environment Interaction ◽  
Genotype Environment Interaction ◽  
And Performance ◽  
Main Components ◽  
Genetic Trends

The objectives of this work were to evaluate the genotype-environment interaction, and estimate genetic parameters, genetic trends, and performance dissimilarity-weight gain from birth to weaning (WGBW), adjusted weight to 205 days (W205), weight gain from weaning to 18 months of age (WG18), and adjusted weight to 550 days (W550)-in Nellore animals born between 1986 and 2012, and raised in pasture-based system in three different environmental gradients in Brazil. Data of 62,001 animals-11,729 raised in the Alto Taquari/Bolsão region (ATBR), 21,143 raised in the Campo Grande/Dourados region (CGDR) and 29,129 raised in the western São Paulo/Paraná region (SPPR) in Brazil-were used. The contemporary groups were defined by sex, location, and birth year and season, with at least nine individuals, two different environments, and breeding bulls with at least five progenies. The statistical model contained the direct additive and residual genetic effects (random effects), and environmental and contemporary group effects (fixed effects). Genetic parameters, genotype-environment interaction and genetic trends were estimates using animal model (uni- and/or bi- traits). The level of similarity between regions was evaluated using principal components. The animals raised in the CGDR had superior performance regarding the traits evaluated. The direct heritability estimates ranged from 0.39 to 0.44 (WGBW), 0.41 to 0.45 (W205), 0.42 to 0.55 (WG18) and 0.60 to 0.62 (W550). The maternal heritability of the traits ranged from 0.20 (WGBW), 0.12 to 0.18 (W205), 0.00 to 0.06 (WG18) and 0.02 to 0.22 (W550). According to the Spearman correlation, the ranking of the breeding bulls in the regions evaluated were different. The mean of Euclidean distance indicated low similarity between ATBR and CGDR (43.20), and ATBR and SPPR (29.24). CGDR and SPPR presented similarity of 17.84. The breed values increased over the years in the traits evaluated. The cumulative variance percentage of the first two main components explained 99.99% variation among the regions, and the weight gains of the animals were the most important to differentiate the regions. A genotype-environment interaction was found for the traits evaluated, thus, the breeding bull selected with superior genetic merit for one region might not be the best for others.

scholarly journals Challenges and adaptive strategies in pig breeding from the aspect of heat stress and heat tolerance

2020 ◽  
Vol 24 (1) ◽  
pp. 1-13
Author(s):  
István Nagy ◽  
György Kövér ◽  
Zsolt Gerencsér ◽  
Gabriella Szász
Keyword(s):  
Heat Tolerance ◽  
Temperature Effects ◽  
Selection Criteria ◽  
Relevant Literature ◽  
Genetic Selection ◽  
Adaptive Strategies ◽  
Environment Interaction ◽  
Genotype Environment Interaction ◽  
Selection For ◽  
The Ideal

Authors summarized the results of the last three decades’ relevant literature examining the temperature effects on the various growth, reproductive and carcass traits in pigs. The ideal period of temperature measurement and the different methodologies characterizing temperature effects were summarized. The aspects of genotype environment interaction for the measured traits under hot and temperate conditions were also presented. Finally the possibilities of direct genetic selection for heat tolerance and its possible selection criteria traits were also discussed.

scholarly journals Selection of corn cultivars for yield, stability, and adaptability in the state of Amazonas, Brazil

2017 ◽  
Vol 52 (6) ◽  
pp. 455-463 ◽  
Author(s):  
Inocencio Junior de Oliveira ◽  
André Luiz Atroch ◽  
Miguel Costa Dias ◽  
Lauro José Guimarães ◽  
Paulo Evaristo de Oliveira Guimarães
Keyword(s):  
Grain Yield ◽  
Genetic Parameters ◽  
Block Design ◽  
The State ◽  
Environment Interaction ◽  
Growing Seasons ◽  
Randomized Complete Block Design ◽  
Selection For ◽  
Genetic Value ◽  
Selection Of

Abstract: The objective of this work was to evaluate corn cultivars grown in the state of Amazonas, Brazil, which simultaneously show high grain yield, adaptability, and stability. The trials were carried out in seven environments in the state of Amazonas, in a randomized complete block design, with two replicates. The grain yield of 30 corn cultivars was evaluated in four growing seasons, from 2011/2012 to 2014/2015. The genetic parameters were estimated by the REML/Blup methodology. The selection for adaptability and stability was based on the predicted genetic value and on the harmonic mean of the relative performance of the genetic values. Despite the existence of genotype x environment interaction, cultivars with high adaptability and stability were identified. Iranduba - lowland, in 2011/2012 and 2014/2015 - and Rio Preto da Eva - upland, in 2012/2013 - stood out as favorable environments, while Iranduba - upland, in 2011/2012 and 2012/2013 - and Manaus - upland, in 2012/2013 and 2013/2014 - were classified as unfavorable environments. The single-cross hybrid BRS 1055 showed productive superiority and high stability in this region. The Sint 10771, Sint 10781, and Sint 10699 synthetic varieties showed high adaptability. BRS Caimbé shows specific adaptability to cropping in upland environments of the state of Amazonas, Brazil.

Genetic parameters and genotype × environment interaction in Pinus taeda clonal tests

2020 ◽  
Vol 474 ◽  
pp. 118342
Author(s):  
Rayssa Chaves Braga ◽  
João Gabriel Zanon Paludeto ◽  
Bruno Marchetti Souza ◽  
Ananda V. Aguiar ◽  
Maria Fernanda M. Pollnow ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Genetic Parameters ◽  
Environment Interaction ◽  
Genotype Environment Interaction

Response to selection in Australian Merino sheep. VIII.* Further results on selection for high clean wool weight with attention to quality

1978 ◽  
Vol 29 (3) ◽  
pp. 615 ◽  
Author(s):  
HN Turner ◽  
N Jackson
Keyword(s):  
Genetic Correlations ◽  
Fibre Diameter ◽  
Control Group ◽  
Environment Interaction ◽  
Genetic Progress ◽  
Weight One ◽  
The Mean ◽  
Selection For ◽  
Made In ◽  
Australian Merino

Results of selection for high clean wool weight per head with control of quality are reported for two selection groups over the period 1966–74. Results for the same experiment for the periods 1950–1959 and 1961–64 were reported earlier. Both groups were selected for high clean wool weight, one (S) with a ceiling on fibre diameter and degree of skin wrinkle, and the other (MS) with a lower limit on staple crimp frequency and a ceiling on skin wrinkle. Genetic progress in clean wool weight was greater in S than in MS over the 1966–74 period (0.12–0.15 lb/annum, compared with 0.06–0.09). This was to be expected from genetic correlations of clean wool weight with fibre diameter (low positive) and staple crimp frequency (high negative). The result supports the previous recommendation that staple crimp frequency is an inefficient way of controlling wool quality while attempting to improve quantity by selection, because its use severely restricts the likely progress in quantity. The actual rate of progress in the S group was similar to that in the period 1950–59, which was followed by a fall in superiority of the selected over the control group animals born during 1961–64. The recovery of response in the 1966–74 period negates the suggestion that the loss of response during the 1961-64 period was due to a 'plateau'. The most likely explanation is that a genotype x environment interaction occurred, such that the genetic gain made in the 1950-59 period could not be expressed in the poorer environments of 1960–65, but reappeared gradually under the improving environment of the 1966–74 period. Attempts to remove this interaction by regression of response on the mean clean wool weight of the unselected control group (as an index of the level of the environment) for each year, were not successful. The interaction is, therefore, not simply a case of all selection groups being equal when the environment is poor. ________________ *Part VII, Aust. J. Agric. Res., 26: 937 (1975).

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