Use of a Pilodyn for the indirect selection of basic density in Eucalyptusnitens

1996 ◽  
Vol 26 (9) ◽  
pp. 1643-1650 ◽  
Author(s):  
B.L. Greaves ◽  
N.M.G. Borralho ◽  
C.A. Raymond ◽  
A. Farrington
Keyword(s):  
Genetic Correlations ◽  
Basic Density ◽  
Indirect Selection ◽  
Selection Intensity ◽  
Selection Efficiency ◽  
Direct Assessment ◽  
Pilodyn Penetration ◽  
Selection For ◽  
High Repeatability ◽  
Selection Of

Six hundred 7-year-old Eucalyptusnitens (Dean & Maid.) trees from 50 open-pollinated families were measured for wood density and Pilodyn penetration across two contrasting sites in eastern Victoria, Australia. Eight Pilodyn observations, two from each of four aspects, were made at a height of 1.3 m. Density was measured on whole disks cut from 1.3 m. Heritability of Pilodyn penetration and disk density at 1.3 m were 0.60 and 0.73, respectively. Phenotypic and genetic correlations between Pilodyn penetration and density at 1.3 m were −0.59 and −0.92, respectively. The high repeatability of Pilodyn penetration (0.90) suggests that only two observations per tree would be required for indirect selection of density. Direct index selection for density gave an expected 13% gain (assuming a selection intensity of 1%), compared with a 11% gain by using indirect Pilodyn selection, a selection efficiency of 84%. However, Pilodyn sampling is faster, cheaper, and not destructive, thus resulting in overall higher expected gains for selection of trees or culling of seedling seed orchards in comparison with the more destructive direct assessment of density.

scholarly journals Genotypic values and genetic correlations for components and oil content of bunch of hybrids between caiaué and dendê

2021 ◽  
Vol 17 (1) ◽  
pp. 79-92
Author(s):  
Alessandra Ferraiolo de Freitas ◽  
Ricardo Lopes ◽  
Raimundo Nonato Vieira da Cunha ◽  
Antônio José de Abreu Pina ◽  
Marcos Deon Vilela Resende ◽  
...  
Keyword(s):  
Oil Content ◽  
Genetic Correlations ◽  
Breeding Population ◽  
Indirect Selection ◽  
Lower Proportion ◽  
Breeding Programs ◽  
Physical Composition ◽  
Selection For ◽  
Positive Correlations ◽  
Selection Of

Interspecific hybridization between Elaeis oleiferaand Elaeisguineensis(HIE OxG) is explored in plant breeding programs to meet the demand for resistant cultivars to fatal yellowing, which is the biggest phytosanitary problem in E. guineensisplants in South America, including Brazil. In addition to resistance to fatal yellowing, cultivars should have high oil yield, which depends directly on bunch production and oil content in the bunches (O/FFB). The obtaining of genetic gains in O/FFBfor OxG requires information on the genotypic values of the breeding population and the understanding of how the components of the bunch are related to this characteristic in this type of material. Thus, the objective of this work was toestimate genotypic values and genetic correlations for bunch components and analyze the potential of using these components in the selection of gains for O/FFB. The physical composition and oil content in mesocarp of 840 bunches from 39 HIE OxG F1 progenies were analyzed. Genotypic values for bunch components were estimated using the procedure REML/BLUP andwere obtained from genetic correlations between them. All evaluated components presented genetic variation with possibility of gains through selection, especially the oil content in the bunch (O/FFB), which presented variability above 23%. The selection for O/FFBwill mainly result in bunches with a higher fruit proportion over the weight of the bunch (TF/FFB), greater oil contents in mesocarp of normal and parthenocarpic fruits, and lower proportion of empty spikelets. Considering the high and positive correlations between O/FFBand the evaluated characteristics and the practicality of evaluation, the characteristics with higher potential for indirect selection to increase O/FFBare TF/FFBand proportion of mesocarp in normal fruits.

scholarly journals JUVENILE-MATURE GENETIC CORRELATIONS IN Pinus taeda CLONES PROPAGATED VIA SOMATIC EMBRYOGENESIS

2016 ◽  
Vol 40 (2) ◽  
pp. 255-267
Author(s):  
Poliana Coqueiro Dias ◽  
Aloisio Xavier ◽  
Marcos Deon Vilela de Resende ◽  
Fabrício Antonio Biernaski ◽  
Regiane Abjaud Estopa ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Pinus Taeda ◽  
Genetic Correlations ◽  
Estimation Procedure ◽  
Early Selection ◽  
Selection Efficiency ◽  
Selection For ◽  
Rotation Age ◽  
High Selection ◽  
Selection Of

ABSTRACT This study aimed to estimate the genetic correlation among selection ages (juvenile - adult) and efficiency of early selection for the height, diameter, and volume traits of individuals from Pinus taeda families propagated via somatic embryogenesis. This study was carried out by genetic-statistical analysis, estimation procedure of variance (Reml), and prediction components of breeding values (Blup), using the Selegen-Reml/Blup software. Genetic correlations among juvenile ages and rotation age were performed by applying the linear model developed by Lambeth (1980). In accordance with results of the established model, the early selection can be performed in clones of Pinus taeda with high selection efficiency. Ages from 4 to 6 years old are enough to select Pinus taeda clones propagated via somatic embryogenesis for harvesting at 8 and 12 years old; and 6 to 10 years old are enough to select them for harvesting at 20 years old. On the basis of the genetic correlations estimates from the environments, the clones' selection of Pinus taeda propagated via somatic embryogenesis should be developed specifically for each environment. The clones' selection can be performed considering the diameter due to the high correlation between volume and diameter.

scholarly journals Clonal Variation and Genotype by Environment Interactions in Growth and Wood Density in Eucalyptus camaldulensis at Three Contrasting Sites in Vietnam

2010 ◽  
Vol 59 (1-6) ◽  
pp. 17-28 ◽  
Author(s):  
N. D. Kien ◽  
G. Jansson ◽  
C. Harwood ◽  
C. Almqvist
Keyword(s):  
Growth Traits ◽  
Basic Density ◽  
Eucalyptus Camaldulensis ◽  
Clonal Variation ◽  
Direct Selection ◽  
North Central ◽  
Genotype By Environment ◽  
Pilodyn Penetration ◽  
Selection For ◽  
Genotypic Correlations

AbstractA total of 172 clones of Eucalyptus camaldulensis were tested in three clonal tests in northern, north-central and southern Vietnam, with 32 of them planted across all three sites. At age 3-5 years, the clonal repeatabilities were 0.18-0.42 for growth traits, 0.71-0.78 for wood basic density and 0.56-0.66 for pilodyn penetration. Genotypic correlations between growth and density at the three sites were from -0.24 to 0.17, and did not differ significantly from zero. Genotypic correlations between sites were 0.32-0.56 for growth traits at age 3 years, and 0.72-0.88 for density and pilodyn penetration. Selection gains for breast height diameter at individual sites at a selection proportion of 5% were 22-32%, with minor effects on density. Selection for diameter at one site gave indirect responses in diameter at the other two sites that were only 40-60% of the gains obtainable from direct selection at those sites. This study shows that fast-growing E. camaldulensis clones can be selected in Vietnam with only minor effects on density. Selection for growth should be regionally based to maximize selection gain whereas clonal rankings for density will change little across regions.

scholarly journals Optimum selection intensities in artificial selection programmes: an experimental evaluation

1977 ◽  
Vol 30 (2) ◽  
pp. 115-119 ◽  
Author(s):  
R. Frankham
Keyword(s):  
Experimental Evaluation ◽  
Selection Intensity ◽  
Effective Population ◽  
Term Selection ◽  
Optimum Selection ◽  
Selection For ◽  
Selection Intensities ◽  
Selection Of ◽  
Better Than

SUMMARYAn experimental evaluation of Robertson's (1970) theory concerning optimum intensities of selection for selection of varying durations has been carried out using published results from a long term selection study in Drosophila. Agreement of predicted rankings of treatments with expectations was excellent for low values of t/T (generations/total number scored) but poor for larger values of t/T. This was due to the 20% selection intensity treatments responding worse than expected and the 40% treatments relatively better than expected. Several possible reasons for the discrepancies exist but the most likely explanation is considered to be the greater reduction in effective population size due to selection in treatments with more intense selection.

scholarly journals Phenotypical resistance correlation networks for 10 non-typhoidalSalmonellasubpopulations in an active antimicrobial surveillance programme

2018 ◽  
Vol 146 (8) ◽  
pp. 991-1002 ◽  
Author(s):  
W. J. Love ◽  
K. A. Zawack ◽  
J. G. Booth ◽  
Y. T. Gröhn ◽  
C. Lanzas
Keyword(s):  
Critical Role ◽  
Genetic Correlations ◽  
Network Models ◽  
Indirect Selection ◽  
Chloramphenicol Resistance ◽  
Surveillance Programme ◽  
Correlation Networks ◽  
Antimicrobial Surveillance ◽  
Partial Correlations ◽  
Selection For

AbstractAntimicrobials play a critical role in treating cases of invasive non-typhoidal salmonellosis (iNTS) and other diseases, but efficacy is hindered by resistant pathogens. Selection for phenotypical resistance may occur via several mechanisms. The current study aims to identify correlations that would allow indirect selection of increased resistance to ceftriaxone, ciprofloxacin and azithromycin to improve antimicrobial stewardship. These are medically important antibiotics for treating iNTS, but these resistances persist in non-TyphiSalmonellaserotypes even though they are not licensed for use in US food animals. A set of 2875Salmonella entericaisolates collected from animal sources by the National Antimicrobial Resistance Monitoring System were stratified in to 10 subpopulations based on serotype and host species. Collateral resistances in each subpopulation were estimated as network models of minimum inhibitory concentration partial correlations. Ceftriaxone sensitivity was correlated with otherβ-lactam resistances, and less commonly resistances to tetracycline, trimethoprim-sulfamethoxazole or kanamycin. Azithromycin resistance was frequently correlated with chloramphenicol resistance. Indirect selection for ciprofloxacin resistance via collateral selection appears unlikely. Density of the ACSSuT subgraph resistance aligned well with the phenotypical frequency. The current study identifies several important resistances in iNTS serotypes and further research is needed to identify the causative genetic correlations.

Usefulness of some components of the lactation curve for selection in Murrah buffaloes

1983 ◽  
Vol 36 (2) ◽  
pp. 277-283
Author(s):  
J. S. Cheema ◽  
S. B. Basu
Keyword(s):  
Milk Yield ◽  
Genetic Correlations ◽  
Indirect Selection ◽  
Direct Selection ◽  
Single Factor ◽  
Daily Production ◽  
Murrah Buffaloes ◽  
Lactation Curve ◽  
Selection For ◽  
Initial Peak

ABSTRACTThe study was based on 1156 lactation records of 545 Murrah buffaloes. Initial milk yield, peak yield, ascending phase milk yield and days to attain peak daily production, the means of which were 26·7 kg, 10·3 kg, 407 kg and 58·9 days respectively, were all affected by period, season and parity of calving. Heifers recorded the least initial milk yield and peak yield and took the longest time to reach peak production. Peak yield was the most important single factor (R2 = 0·41) in causing variation in 43-week milk yield. The heritability estimates for initial, peak and ascending phase milk yields and days to attain peak yield were 0·35, 0·51, 0·27 and 0·13 respectively, whilst that for 43-week milk yield was 0·18. Peak yield had the highest phenotypic (rP = 0·64) and genetic correlations (ra = 0·68 ± 0·19) with the 43-week milk yield. Other genetic correlations with the 43-week milk yield were low and non-significant. The results indicated that indirect selection for peak yield would be more effective than direct selection for improving the 43-week milk yield in buffaloes.

scholarly journals Influence of Ascites Syndrome on Growth Pattern of Chickens Reared at Normal or Cold Ambient Temperature

2015 ◽  
Vol 15 (2) ◽  
pp. 373-385 ◽  
Author(s):  
Karim Hasanpur ◽  
Mohammadreza Nassiry ◽  
Ghasem Hosseini Salekdeh ◽  
Rasul Vaez Torshizi ◽  
Abbas Pakdel ◽  
...  
Keyword(s):  
Selective Breeding ◽  
Genetic Correlations ◽  
Case Selection ◽  
Rapid Growth Rate ◽  
Simultaneous Selection ◽  
Selection For ◽  
Financial Losses ◽  
Selection Of ◽  
Meat Type ◽  
Ascites Syndrome

Abstract Ascites syndrome (AS) is a metabolic disorder usually seen in highly improved meat-type broiler strains. This syndrome causes major financial losses to the poultry industry. Previously it was believed that AS incidence was a side effect of intense selection for rapid growth rate (GR) or higher market weight. If this belief is the case, selection for further increase in GR will not be rational. However, it was later understood that there were significant genetic variations for both GR and susceptibility/resistance to AS; thus selective breeding could be helpful in diminishing the incidence of AS while improving GR. Furthermore, it was hypothesized that genes controlling the GR were not genetically dependent on those genes controlling susceptibility to AS. In the current research, we aimed to study the association of GR traits with AS% in a pure sire line. A total of 1458 1-day-old chicks from 67 sire families were used. The results revealed that ascitic chicks were not significantly superior in early GR traits (i.e. before day 28) than the healthy ones. At later ages, probably due to the commencement of the syndrome, the ascitic chicks were significantly lighter in body weight (BW) than their healthy counterparts. The lack of significant genetic correlations between the GR traits and AS% indicated that there was considerable scope for simultaneous selection of birds for increased BW and GR while controlling susceptibility to AS.

Heritability, correlated response, and indirect selection involving spectral reflectance indices and grain yield in wheat

2007 ◽  
Vol 58 (5) ◽  
pp. 432 ◽  
Author(s):  
M. A. Babar ◽  
M. van Ginkel ◽  
M. P. Reynolds ◽  
B. Prasad ◽  
A. R. Klatt
Keyword(s):  
Grain Yield ◽  
Spectral Reflectance ◽  
Genetic Correlations ◽  
Grain Filling ◽  
Indirect Selection ◽  
The Other ◽  
Correlated Response ◽  
Response To Selection ◽  
Selection For ◽  
Reflectance Indices

The objectives of this study were to assess the potential of using spectral reflectance indices (SRIs) as an indirect selection tool for grain yield in wheat under irrigated conditions. This paper demonstrates the genetic correlation between grain yield and SRIs, heritability and expected response to selection for grain yield and SRIs, correlated response to selection for grain yield estimated from SRIs, and efficiency of indirect selection for grain yield using SRIs in different spring wheat populations. Four field experiments, GHIST (15 CIMMYT globally adapted genotypes), RLs1 (25 random F3-derived families), RLs2 (36 random F3-derived families), and RLs3 (64 random F5-derived families) were conducted under irrigated conditions at the CIMMYT research station in north-west Mexico in 3 different years. Spectral reflectance was measured at 3 growth stages (booting, heading, and grain filling) and 7 SRIs were calculated using average values of spectral reflectance at heading and grain filling. Five previously developed SRIs (PRI, WI, RNDVI, GNDVI, SR), and 2 newly calculated SRIs (NWI-1 and NWI-2) were evaluated in the experiments. In general, the within- and between-year genetic correlations between grain yield and SRIs were significant. Three NIR-based indices (WI, NWI-1, and NWI-2) showed higher genetic correlations (0.73–0.92) with grain yield than the other indices (0.35–0.67), and these observations were consistent in all populations. Broad-sense heritability estimates for all indices were in general moderate to high (0.60–0.80), and higher than grain yield (0.45–0.70). The realised heritability for the 3 NIR-based indices was higher than for the other indices and for grain yield itself. Expected response to selection for all indices was moderate to high (0.54–0.85). The correlated response for grain yield estimated from the 3 NIR-based indices (0.59–0.64) was much higher than the correlated response for grain yield estimated from the other indices (0.31–0.46), and the efficiency of indirect selection for these 3 NIR-based indices was 90–96% of the efficiency of direct selection for grain yield. These results demonstrate the potential for using the 3 NIR-based SRI tools in breeding programs for selecting for increased genetic gains for yield.

The genetic basis of growth, reproduction, and maternal environment in Romney ewes. II.* Genetic covariation between hogget characters, fertility, and maternal environment of the ewe

1972 ◽  
Vol 23 (1) ◽  
pp. 149 ◽  
Author(s):  
TS Ch'ang ◽  
AL Rae
Keyword(s):  
New Zealand ◽  
Genetic Gain ◽  
Predictive Accuracy ◽  
Genetic Correlations ◽  
Direct Selection ◽  
Maternal Environment ◽  
Subsequent Fertility ◽  
Selection For ◽  
Reproductive Characters ◽  
Selection Of

This paper is the second in a series of studies on the genetic variation and covariation in growth and reproductive characters of the New Zealand Romney sheep. The data used were obtained over a period of 11 years (1955–1965 inclusive) from a random bred experimental flock maintained at Massey University, Palmerston North, New Zealand. Phenotypic correlations were estimated between the ewe's liveweights, oestrous performance at the hogget stage (from weaning to about 14 months), and her subsequent fertility (number of lambs born per ewe) at the first lambing (2-year-old) or over several lambings. These correlations were compared from the viewpoint of accuracy in predicting, prior to first mating, a young ewe's potential fertility over one or several lambings during her own lifetime. The results suggest that for this purpose, the predictive accuracy of the hogget characters is generally low but comparable with, and in some cases, substantially greater than, that obtainable from fertility records belonging to the dam of the young ewe. Three different methods were used to estimate the genetic correlations. In general, the pattern of genetic correlations, either within the hogget characters or between them and fertility of the ewe, is predominantly one of positive values ranging from moderate size to unity. In contrast, most of the maternal genetic correlations were negative. The relative efficiency of indirect versus direct selection for genetic gain in various characters was examined under different assumptions made with regard to the maternal effect. Indirect selection, based on the measurement of hogget (yearling) liveweight or number of hogget oestruses, for genetic gain in fertility of the Romney ewe is expected, on present evidence, to be more efficient than direct selection. Of the two characters, hogget liveweight is likely to find wider application because it can be more easily measured. _________________ *Part I, Aust. J. Agric. Res., 21: 115 (1970)

scholarly journals Long-term comparison between index selection and optimal independent culling in plant breeding programs with genomic prediction

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0235554
Author(s):  
Lorena G. Batista ◽  
Robert Chris Gaynor ◽  
Gabriel R. A. Margarido ◽  
Tim Byrne ◽  
Peter Amer ◽  
...  
Keyword(s):  
Recurrent Selection ◽  
Genetic Correlations ◽  
Economic Importance ◽  
Index Selection ◽  
Selection Intensity ◽  
Crop Breeding ◽  
Breeding Programs ◽  
Independent Culling ◽  
Selection Of

In the context of genomic selection, we evaluated and compared breeding programs using either index selection or independent culling for recurrent selection of parents. We simulated a clonally propagated crop breeding program for 20 cycles using either independent culling or an economic index with two unfavourably correlated traits under selection. Cycle time from crossing to selection of parents was kept the same for both strategies. Both methods led to increasingly unfavourable genetic correlations between traits and, compared to independent culling, index selection led to larger changes in the genetic correlation between the two traits. When linkage disequilibrium was not considered, the two methods had similar losses of genetic diversity. Two independent culling approaches were evaluated, one using optimal culling levels and one using the same selection intensity for both traits. Optimal culling levels outperformed the same selection intensity even when traits had the same economic importance. Therefore, accurately estimating optimal culling levels is essential for maximizing gains when independent culling is performed. Once optimal culling levels are achieved, independent culling and index selection lead to comparable genetic gains.

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