scholarly journals Genetic study with Heliconia psittacorum and interspecific hybrids

2010 ◽  
Vol 10 (4) ◽  
pp. 282-288 ◽  
Author(s):  
Francisco Herverton Albuquerque Rocha ◽  
Vivian Loges ◽  
Andreza Santos da Costa ◽  
Fernando Antônio Souza de Aragão ◽  
Venézio F Santos
Keyword(s):  
Genetic Variation ◽  
Total Variation ◽  
Genetic Study ◽  
Interspecific Hybrids ◽  
Genetic Correlations ◽  
Heritability Estimate ◽  
Stem Diameter ◽  
Variation Coefficient ◽  
Shoot Emergence ◽  
Inflorescence Length

A genetic study of seven cultivars of H. psittacorum and Heliconia interspecific hybrids was carried out. The heritability estimate and genetic variation coefficient were highest for stem diameter (SD) (99.32% and 56.90%, respectively) and for CVg/CVe (1.85), indicating a favorable situation for selection. The genetic correlations of SD with days to inflorescence emergence (DIE) (0.64), period from shoot emergence to stem cut (CYCLE) (0.63) and stem weight (SW) (0.96) showed that the time from inflorescence emergence to cut is longer and the stem weight is greater for genotypes with larger stem diameter. Inflorescence length (IL), SD and DIE were the most important traits, accounting for 99.55% of the total variation. For SD and IL, the repeatability values exceeded 0.60 and for SD, SW, DIE and IL the coefficients of determination exceeded 93%.

Genetic variation in serum copper concentration in Angus cattle

2006 ◽  
Vol 82 (6) ◽  
pp. 799-803 ◽  
Author(s):  
C. A. Morris ◽  
N. C. Amyes ◽  
S. M. Hickey
Keyword(s):  
Genetic Variation ◽  
Genetic Correlations ◽  
Heritability Estimate ◽  
Serum Copper ◽  
Phenotypic Correlation ◽  
Environmental Correlations ◽  
Angus Cattle ◽  
Supplementation Period ◽  
Zn Concentration ◽  
Genetic Level

AbstractFollowing the discovery of low serum copper (Cu) concentrations in 9-month-old beef calves at pasture in autumn (50% of animals had values <7·5 μmol/l), genetic variation in serum Cu concentration was studied in an experimental Angus herd in New Zealand, monitoring at intervals from about 7 to 17 months of age. The study was initiated in autumn when animals were supplemented with zinc (Zn) salts (to protect against liver injury from toxin-producing facial eczema spores on the pasture), and later in the production year after Cu supplementation but without Zn supplementation. Heritabilities of Cu concentration were estimated in 837 calves from six calf crops, the progeny of 47 sires, using restricted maximum likelihood procedures with an animal model. Correlations between Cu concentration and Zn concentration were also estimated, along with correlations between Cu concentration and 6-month, 9-month and yearling live weights. The heritability estimate for Cu concentration at all times outside the autumn Zn supplementation period was 0·28±0·08 (between-animal repeatability, 0·30±0·05), and the heritability estimates for autumn Cu concentration and Zn concentration were 0·35±0·11 and 0·26±0·13, respectively. The genetic and environmental correlations between autumn Cu concentration and Zn concentration were ?0·29±0·31 and 0·15±0·11, respectively, suggesting antagonistic effects between Zn and Cu only at the genetic level, with a net (phenotypic) correlation of 0·02±0·06. Genetic correlations between Cu concentration (outside the autumn season) and 6-month, 9-month and yearling weights ranged from 0·15±0·15 to 0·17±0·16. It was concluded that serum Cu and Zn concentrations in calves were heritable traits under the grazing conditions encountered, and that index selection to increase live weights and Cu concentrations could be applied if desired.

scholarly journals Genetic Variation and Correlations between Growth and Wood Density of Calycophyllum spruceanum at an Early Age in the Peruvian Amazon

2006 ◽  
Vol 55 (1-6) ◽  
pp. 217-228 ◽  
Author(s):  
Sotelo Montes ◽  
R. E. Hernández ◽  
J. Beaulieu ◽  
J. C. Weber
Keyword(s):  
Genetic Variation ◽  
Genetic Control ◽  
Wood Density ◽  
Amazon Basin ◽  
Genetic Correlations ◽  
Basic Density ◽  
Ground Level ◽  
Wood Properties ◽  
Stem Diameter ◽  
Peruvian Amazon

Abstract Calycophyllum spruceanum (Benth.) Hook. f. ex K. Shum. is an important timber-tree species in the Peruvian Amazon Basin. As farmers and industry often use wood from young trees, it is important to investigate variation in juvenile wood properties in this species. A provenance/progeny test was established to evaluate genetic variation in growth and wood properties of young trees, the strength of their genetic control as well as their interrelationships both at the genetic and the phenotypic level in different planting zones. In this paper, results are presented for tree height and stem diameter (near ground level) at 16, 28 and 39 months; and stem diameter and basic density of the wood at breast height at 39 months. Significant variation due to provenances and especially due to families within provenances was found in growth and wood density. Phenotypic and genetic correlations indicated that larger trees tended to have denser wood. Wood density had higher heritability than height and diameter; and genetic control over height, diameter and density was generally highest in the planting zone where trees grew most rapidly.

Vernalization Accelerates Flowering of Lysimachia clethroides Duby

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 508b-508
Author(s):  
Pamela M. Lewis ◽  
Alan M. Armitage ◽  
Jim M. Garner
Keyword(s):  
Stem Diameter ◽  
Stem Length ◽  
Cut Flower ◽  
Bud Formation ◽  
Flower Production ◽  
Sphagnum Peat ◽  
Potting Media ◽  
Lysimachia Clethroides ◽  
Shoot Emergence

The effect of vernalization method and duration on off-season cut flower production of Lysimachia clethroides Duby was examined. Rhizomes harvested in October were cooled for 0, 4, 6, 8, 10 or 12 weeks at 4 ± 1 °C in crates with unmilled sphagnum peat or in 3.75-L pots with potting media prior to forcing in a warm greenhouse. After 6 or more weeks of cooling, shoots emerged from crate-cooled rhizomes in higher percentages than from pot-cooled rhizomes. However, only the duration of cooling, not the method, affected the rate of shoot emergence, visible bud formation and anthesis of the first bud in the raceme. As cooling increased from 0 to 12 weeks, the greenhouse days required for shoot emergence, visible bud formation and anthesis decreased linearly. The number of flowering flushes and flowering stems varied quadratically with cooling duration, and the highest yields occurred when rhizomes received between 4 and 10 weeks of cooling. As the number of successive flowering flushes increased, the stem length increased linearly while the stem diameter decreased linearly. High numbers of flowers were produced rapidly after 10 weeks of cooling.

scholarly journals Genetic variation and relationships of seven sturgeon species and ten interspecific hybrids

2013 ◽  
Vol 45 (1) ◽  
pp. 21 ◽  
Author(s):  
Xiaomin Zhang ◽  
Wenhua Wu ◽  
Linmiao Li ◽  
Xufa Ma ◽  
Jinping Chen
Keyword(s):  
Genetic Variation ◽  
Interspecific Hybrids ◽  
Sturgeon Species

Genetic Parameters and Genotype-by-Environment Interactions in Regional Progeny Tests of Pinus taeda L. in the Southern USA

2020 ◽  
Author(s):  
Edwin Lauer ◽  
Andrew Sims ◽  
Steven McKeand ◽  
Fikret Isik
Keyword(s):  
Genetic Variation ◽  
Pinus Taeda ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Breeding Program ◽  
Model Fit ◽  
Genotype By Environment Interactions ◽  
Genotype By Environment ◽  
Progeny Tests ◽  
Pinus Taeda L

Abstract Genetic parameters were estimated using a five-series multienvironment trial of Pinus taeda L. in the southern USA. There were 324 half-sib families planted in five test series across 37 locations. A set of six variance/covariance matrices for the genotype-by-environment (G × E) effect for tree height and diameter were compared on the basis of model fit. In single-series analysis, extended factor analytical models provided generally superior model fit to simpler models for both traits; however, in the combined-series analysis, diameter was optimally modeled using simpler variance/covariance structures. A three-way compound term for modeling G × E interactions among and within series yielded substantial improvements in terms of model fit and standard errors of predictions. Heritability of family means ranged between 0.63 and 0.90 for both height and diameter. Average additive genetic correlations among sites were 0.70 and 0.61 for height and diameter, respectively, suggesting the presence of some G × E interaction. Pairs of sites with the lowest additive genetic correlations were located at opposite ends of the latitude range. Latent factor regression revealed a small number of parents with large factor scores that changed ranks significantly between southern and northern environments. Study Implications Multienvironmental progeny tests of loblolly pine (Pinus taeda L.) were established over 10 years in the southern United States to understand the genetic variation for the traits of economic importance. There was substantial genetic variation between open-pollinated families, suggesting that family selection would be efficient in the breeding program. Genotype-by-environment interactions were negligible among sites in the deployment region but became larger between sites at the extremes of the distribution. The data from these trials are invaluable in informing the breeding program about the genetic merit of selection candidates and their potential interaction with the environment. These results can be used to guide deployment decisions in the southern USA, helping landowners match germplasm with geography to achieve optimal financial returns and conservation outcomes.

scholarly journals The Molecular Basis of Quantitative Genetic Variation in Central and Secondary Metabolism in Arabidopsis

Genetics ◽  
1998 ◽  
Vol 149 (2) ◽  
pp. 739-747 ◽  
Author(s):  
Thomas Mitchell-Olds ◽  
Deana Pedersen
Keyword(s):  
Enzyme Activity ◽  
Genetic Variation ◽  
Secondary Metabolism ◽  
Genetic Correlations ◽  
Theoretical Models ◽  
Model Systems ◽  
Activity Levels ◽  
Significant Qtls ◽  
Cis Acting ◽  
Quantitative Genetic

Abstract To find the genes controlling quantitative variation, we need model systems where functional information on physiology, development, and gene regulation can guide evolutionary inferences. We mapped quantitative trait loci (QTLs) influencing quantitative levels of enzyme activity in primary and secondary metabolism in Arabidopsis. All 10 enzymes showed highly significant quantitative genetic variation. Strong positive genetic correlations were found among activity levels of 5 glycolytic enzymes, PGI, PGM, GPD, FBP, and G6P, suggesting that enzymes with closely related metabolic functions are coregulated. Significant QTLs were found influencing activity of most enzymes. Some enzyme activity QTLs mapped very close to known enzyme-encoding loci (e.g., hexokinase, PGI, and PGM). A hexokinase QTL is attributable to cis-acting regulatory variation at the AtHXK1 locus or a closely linked regulatory locus, rather than polypeptide sequence differences. We also found a QTL on chromosome IV that may be a joint regulator of GPD, PGI, and G6P activity. In addition, a QTL affecting PGM activity maps within 700 kb of the PGM-encoding locus. This QTL is predicted to alter starch biosynthesis by 3.4%, corresponding with theoretical models, suggesting that QTLs reflect pleiotropic effects of mutant alleles.

scholarly journals Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones

2004 ◽  
Vol 34 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Marcelo Renato Alves de Araújo ◽  
Bruce Coulman
Keyword(s):  
Genetic Variation ◽  
Crude Protein ◽  
Genetic Correlations ◽  
Neutral Detergent Fiber ◽  
Broad Sense ◽  
Grass Species ◽  
Broad Sense Heritability ◽  
Bromus Riparius ◽  
Heritability Estimates ◽  
Meadow Bromegrass

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.

Genetic variation in net feed efficiency in Hereford cattle and its association with other production traits

1999 ◽  
Vol 1999 ◽  
pp. 47-47
Author(s):  
R.M. Herd ◽  
S.C. Bishop
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Genetic Correlations ◽  
Feed Consumption ◽  
Production Traits ◽  
Performance Measurements ◽  
Hereford Cattle ◽  
Rate Selection

Net feed efficiency refers to variation in feed consumption between animals net of requirements for maintenance and production, and may be measured as residual feed intake (RFI). Because RFI is independent of liveweight (LW) and growth rate, selection for improved net feed efficiency is likely to reduce feed intake with little change in growth. The purpose of this study was to establish whether there exists genetic variation in RFI in young British Hereford bulls, and to determine the phenotypic and genetic correlations of RFI with key production traits.The data consisted of performance measurements on 540 bull progeny of 154 British Hereford sires, collected over ten 200-day postweaning performance tests conducted between 1979 and 1988. The traits analysed were food intake (FI), 200 to 400-day daily gain (ADG), 400-day weight (W400), predicted carcass lean content (LEAN), lean growth rate (LGR), food conversion ratio (FI/ADG) and lean FCR (LFCR; FI/(ADG x LEAN), described by Bishop (1992).

Genetic variation in fatty acid composition of subcutaneous fat in cattle

2013 ◽  
Vol 53 (2) ◽  
pp. 129 ◽  
Author(s):  
M. J. Kelly ◽  
R. K. Tume ◽  
S. Newman ◽  
J. M. Thompson
Keyword(s):  
Fatty Acids ◽  
Genetic Variation ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Saturated Fatty Acids ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Monounsaturated Fatty Acids ◽  
Selection For

Genetic parameters were estimated for fatty acid composition of subcutaneous beef fat of 1573 animals which were the progeny of 157 sires across seven breeds grown out on pasture and then finished on either grain or grass in northern New South Wales or in central Queensland. There was genetic variation in individual fatty acids with estimates of heritability for the proportions of C14 : 0, C14 : 1c9, C16 : 0, C16 : 1c9, C18 : 0 and C18 : 1c9 fatty acids in subcutaneous beef fat of the order of 0.4 or above. Also substantial correlations between some fatty acids were observed. Genetic correlations between fatty acids and fat depth at the P8 site suggested that much of the genetic variation in fatty acid composition was related to changes in fatness. Selection for decreased fatness resulted in decreased proportions of C18 : 1c9 with concomitant increases in C18 : 0, C14 : 0 and C16 : 0. This suggested that selection for decreased fatness at a given weight will result in a decrease in the proportions of monounsaturated fatty acids in the subcutaneous fat in the carcass with a corresponding increase in the proportions of saturated fatty acids.

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