Quantitative genetics of yield breeding for Populus short rotation culture. I. Dynamics of genetic control and selection model of yield traits

1992 ◽  
Vol 22 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Rong-Ling Wu ◽  
Ming-Xiu Wang ◽  
Min-Ren Huang
Keyword(s):  
Growth Traits ◽  
Volume Growth ◽  
Broad Sense ◽  
Eastern Cottonwood ◽  
Short Rotation ◽  
Environmental Regimes ◽  
Variation Patterns ◽  
Selection Intensities ◽  
Two Hybrid ◽  
Selection Of

Variation patterns and selection efficiencies for the three growth traits height, diameter, and volume were studied in two selected interspecific hybrid populations of eastern cottonwood (Populusdeltoides Bartr.): P. deltoides × Populussimonii Carr. and P. deltoides × Populusnigra L. Growth variables differed quite significantly (P < 0.01) among clones in each of the two hybrid populations, and they were more dominantly controlled by genetic factors than by environmental regimes. There were higher broad-sense heritablity levels for growth traits in this study than in other related studies. Genetic variances and broad-sense heritabilities for all traits markedly increased with stand development in the two hybrid populations; but the increasing rates with age of these two genetic parameters for diameter and volume were more rapid for P. deltoides × P. simonii hybridization than for P. deltoides × P. nigra hybridization. Selection of the best 5% of the clones from P. deltoides × P. simonii and the best 10% from P. deltoides × P. nigra produced mean 6th-year volume growth increases of 51 and 37%, respectively. Relative to P. deltoides, their high parent, the ratio of clonal heterosis of these selected hybrid clones was 5–23% for 6th-year volume. With different selection intensities, early selection of juvenile growth traits for the two populations, P. deltoides × P. simonii and P. deltoides × P. nigra, can also produce substantial indirect genetic gains for short rotation harvest traits. Further studies of Populus yield breeding and selection models were suggested.

Populustrichocarpa × Populusdeltoides hybrids for short rotation culture: variation patterns and 4-year field performance

1988 ◽  
Vol 18 (6) ◽  
pp. 745-753 ◽  
Author(s):  
Reinhard F. Stettler ◽  
Ruth C. Fenn ◽  
Paul E. Heilman ◽  
Brian J. Stanton
Keyword(s):  
Rank Order ◽  
Volume Growth ◽  
Field Tests ◽  
Field Performance ◽  
Leaf Traits ◽  
Short Rotation ◽  
Hybrid Superiority ◽  
Variation Patterns ◽  
Rotation Culture ◽  
Western Washington

Studies were conducted on the comparative growth and morphology of Populustrichocarpa (T), P. deltoides (D), F1 hybrids (T×D), F2 hybrids (TD × TD), and B1 hybrids (T × TD, TD × T) at one nursery and two plantation sites in western Washington and Oregon. First coppice resprouts in the nursery showed intermediacy of the F1 and F2 between parentals in four of five morphological leaf traits measured, and intermediacy of B1 values between F1 and T in three. Amounts of variation generally conformed to the model of F2 > B1 > F1. The percent significant trait correlations were 11.6 for the F1, 8.7 for the B1, and zero for the F2. No simply inherited traits were identified. Growth in the first and successive coppices in the nursery was significantly greater in the F1 than in the B1 and F2 generations. The same trend was observed in two field tests at Pack Forest, Washington and Westport, Oregon in which 691 and 381 clones from 60 and 42 families, respectively, gave a rank order in 4-year volume growth of F1 > B1 > T > F2 > D. Several F1 families and clones showed high rank consistency between years and locations. The results confirm earlier studies and are discussed in relation to the mechanisms that underlie T × D hybrid superiority.

Breeding for improved growth and juvenile corewood stiffness in slash pine

2007 ◽  
Vol 37 (10) ◽  
pp. 1886-1893 ◽  
Author(s):  
Xiaobo Li ◽  
Dudley A. Huber ◽  
Gregory L. Powell ◽  
Timothy L. White ◽  
Gary F. Peter
Keyword(s):  
Genetic Correlation ◽  
Growth Traits ◽  
Low Cost ◽  
Genetic Correlations ◽  
Volume Growth ◽  
Pinus Elliottii ◽  
Tree Improvement ◽  
Slash Pine ◽  
Narrow Sense Heritability ◽  
Improvement Programs

The importance of integrating measures of juvenile corewood mechanical properties, modulus of elasticity in particular, with growth and disease resistance in tree improvement programs has increased. We investigated the utility of in-tree velocity stiffness measurements to estimate the genetic control of corewood stiffness and to select for trees with superior growth and stiffness in a progeny trial of 139 families of slash pine, Pinus elliottii Engelm. grown on six sites. Narrow-sense heritability estimates across all six sites for in-tree acoustic velocity stiffness at 8 years (0.42) were higher than observed for height (0.36) and diameter at breast height (DBH) (0.28) at 5 years. The overall type B genetic correlation across sites for velocity stiffness was 0.68, comparable to those found for DBH and volume growth, indicating that family rankings were moderately repeatable across all sites for these traits. No significant genetic correlations were observed between velocity stiffness, DBH, and volume growth. In contrast, a significant, but small, favorable genetic correlation was found between height and velocity stiffness. Twenty percent of the families had positive breeding values for both velocity stiffness and growth. The low cost, high heritability and nearly independent segregation of the genes involved with in-tree velocity stiffness and growth traits indicate that acoustic methods can be integrated into tree improvement programs to breed for improved corewood stiffness along with growth in slash pine.

scholarly journals Melanocortin-4 receptor and leptin as genes for the selection of superior Madrasin cattle

2021 ◽  
pp. 3224-3228
Author(s):  
Budi Utomo ◽  
Rimayanti Rimayanti ◽  
Indah Norma Triana ◽  
Amaq Fadholly
Keyword(s):  
Genetic Improvement ◽  
Fragment Length Polymorphism ◽  
Growth Traits ◽  
Molecular Characteristics ◽  
Chain Reaction ◽  
Mc4r Gene ◽  
Melanocortin 4 Receptor ◽  
Polymerase Chain ◽  
Selection Of ◽  
Restriction Fragment Length

Background and Aim: The genetic improvement of cattle through livestock section is based on quantitative, qualitative, and molecular characteristics. This study examined polymorphisms of the melanocortin-4 receptor (MC4R) and leptin genes as a reference for the selection of superior breeds in Madrasin cattle. Materials and Methods: The leptin and MC4R genes of Madrasin cattle were amplified using polymerase chain reaction (PCR); then, restriction fragment length polymorphism of the leptin gene was performed using the restriction enzyme BsaA1, at site 2793 with ACGT point position. Results: The leptin gene was divided into three bands, namely, AA with one fragment (522 bp), CG with two fragments (441 bp and 81 bp), and AG with three fragments (522 bp, 441 bp, and 81 bp). The MCR-4 gene was divided into three bands, namely, 493 bp, 318 bp, and 175 bp. Conclusion: The MC4R and leptin genes can act as molecular markers for growth traits in Madrasin cattle and can be used to genetically optimize and improve growth. The GG allele of the MC4R gene and the AA allele of the leptin gene can be used in Madrasin cattle.

PSVII-28 Genetic analysis of frame score and performance traits in Nellore cattle–growth, carcass and efficiency traits

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 238-239
Author(s):  
Maria Paula Negreiros ◽  
Elisa Peripolli ◽  
Claudio U Magnabosco ◽  
Nayanny Guimarães ◽  
Raysildo Lôbo ◽  
...  
Keyword(s):  
Animal Model ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Heritability Estimate ◽  
Score System ◽  
Adult Weight ◽  
Nellore Cattle ◽  
And Performance ◽  
Selection Of

Abstract We evaluated a novel frame score system for Nellore cattle raised on pasture (Guimarães et al., 2020 J, Anim. Sci. 98 (Suppl. 4)). Growth traits included age-adjusted weights (kg) at birth (W0), 120 (W120), 210 (W210) and 450 (W450) days of age, and adult weight (AW). Carcass traits (by ultrasound) included ribeye area (REA, cm2), 12th-13th rib backfat (BF, mm), rump fat (RF, mm), and intramuscular fat (IMF, %). Feed efficiency traits included residual feed intake (RFI, kg of DM/d) and DM intake (DMI, kg/d). We applied the previously developed equations (that also include hip height (HH, cm) and age to 12,049 records from the National Association of Breeders and Researchers (ANCP) database:FSmales= -20.35 + 0.1305*REA + 0.2633*BF - 0.5901*RF+ 0.1139*HH + 0.0056*AGEFSfemales = -11.87 + 0.1316*REA - 0.2457*BF - 0.6218*RF + 0.1139*HH + 0.0009507*AGEThe (co)variance components and genetic parameters were estimated using a linear animal model or a threshold animal model depending on the trait. The heritability estimate for frame score was moderate (0.30). Estimated genetic correlations were moderate for growth traits (W0, 0.51; W120, 0.41; W210, 0.35; W450, 0.29; AW, 0.39). Estimated genetic correlations for carcass and efficiency traits ranged from low to high (REA, 0.50; BF, -0.25; RF, -0.84; IMF, -0.15; DMI, 0.29; RFI, 0.10). The estimates support the notion that larger frame animals are heavier, leaner and later maturing, and less feed efficient. The new frame score may be a useful tool for genetic selection of animals that are best suited to their environment.

scholarly journals Evolution of Microbial Growth Traits Under Serial Dilution

Genetics ◽  
2020 ◽  
Vol 215 (3) ◽  
pp. 767-777
Author(s):  
Jie Lin ◽  
Michael Manhart ◽  
Ariel Amir
Keyword(s):  
Growth Rate ◽  
Growth Traits ◽  
Lag Time ◽  
Microbial Evolution ◽  
Serial Dilution ◽  
Direct Selection ◽  
Dilution Factor ◽  
Beneficial Mutation ◽  
Experimental Parameters ◽  
Selection Of

Selection of mutants in a microbial population depends on multiple cellular traits. In serial-dilution evolution experiments, three key traits are the lag time when transitioning from starvation to growth, the exponential growth rate, and the yield (number of cells per unit resource). Here, we investigate how these traits evolve in laboratory evolution experiments using a minimal model of population dynamics, where the only interaction between cells is competition for a single limiting resource. We find that the fixation probability of a beneficial mutation depends on a linear combination of its growth rate and lag time relative to its immediate ancestor, even under clonal interference. The relative selective pressure on growth rate and lag time is set by the dilution factor; a larger dilution factor favors the adaptation of growth rate over the adaptation of lag time. The model shows that yield, however, is under no direct selection. We also show how the adaptation speeds of growth and lag depend on experimental parameters and the underlying supply of mutations. Finally, we investigate the evolution of covariation between these traits across populations, which reveals that the population growth rate and lag time can evolve a nonzero correlation even if mutations have uncorrelated effects on the two traits. Altogether these results provide useful guidance to future experiments on microbial evolution.

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 Heritability of Simulated Wear and Traffic Tolerance in Three Fine Fescue Species

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 416-420 ◽  
Author(s):  
Austin L. Grimshaw ◽  
Yuanshuo Qu ◽  
William A. Meyer ◽  
Eric Watkins ◽  
Stacy A. Bonos
Keyword(s):  
Broad Sense ◽  
Potential Candidate ◽  
Single Individual ◽  
Broad Sense Heritability ◽  
The North ◽  
Heritability Estimates ◽  
Traffic Tolerance ◽  
Fine Fescue ◽  
Selection Of ◽  
Wear Tolerance

In recent years, turfgrass breeders have given increased attention to the development of lower maintenance turfgrass cultivars. Fine fescues (Festuca spp.) have been identified as potential candidate species for low-maintenance lawns because of their reduced need for water, mowing, and fertilizer. Unfortunately, these species have some weaknesses that must be improved to facilitate their use; perhaps, the most important of these is tolerance to wear and traffic. For this trait to be improved in new cultivars, there must be sufficient heritable variation available for plant breeders to exploit; however, little is known about the heritability of this complex trait in fine fescue species. Therefore, the objective of this study was to determine the heritability of wear and traffic tolerance in three fine fescue species. Replicated field studies were established in North Brunswick, NJ, and St. Paul, MN, and each included 157 Chewing’s fescue (Festuca rubra L. subsp. fallax), 155 hard fescue (Festuca brevipilia), and 149 strong creeping red fescue (F. rubra L. subsp. rubra) genotypes. Wear tolerance was evaluated in North Brunswick and traffic tolerance was evaluated in St. Paul during 2015 and 2016 using different simulators to determine both plant performance and broad-sense heritability estimates for wear and traffic tolerance. Broad-sense heritability estimates for the three species when calculated on a clonal basis was between 0.69 and 0.82 for wear tolerance in the North Brunswick location and between 0.49 and 0.60 for traffic tolerance in the St. Paul location. On a single-plant basis, broad-sense heritability estimates for the three species were between 0.31 and 0.45 for wear tolerance in the North Brunswick location and 0.09 and 0.12 for traffic tolerance in St. Paul. However, this research does indicate that improvement of wear and traffic tolerance in fine fescues is possible through recurrent breeding methods based on selection of replicated clonally propagated genotypes rather than selection of single individual plants of a population. This was the first study to determine the genetic effects of wear and traffic tolerance in any turfgrass species.

scholarly journals Response to selection of a breeding program for Suffolk sheep in the Czech Republic

2018 ◽  
Vol 63 (No. 8) ◽  
pp. 305-312 ◽  
Author(s):  
Ptáček Martin ◽  
Ducháček Jaromír ◽  
Schmidová Jitka ◽  
Stádník Luděk
Keyword(s):  
Czech Republic ◽  
Growth Traits ◽  
Live Weight ◽  
Backfat Thickness ◽  
Sheep Population ◽  
The Czech Republic ◽  
Longissimus Lumborum ◽  
The Difference ◽  
Selection Of ◽  
Suffolk Sheep

Lamb growth performance traits in relation to parental breeding values (BVs) for these traits were evaluated in a purebred Suffolk sheep population in the Czech Republic. The research lasted over 8 years and included 24 886 lambs. Four relevant parental BVs were observed: BV predicted for lamb live weight direct effect (BVLW-DE), BV predicted for lamb live weight maternal effect (BVLW-ME), BV predicted for lamb musculus longissimus lumborum et thoracis depth (BV-MLLT), and BV predicted for lamb backfat thickness (BV-BT). The lamb live weight (LW; kg), musculus longissimus lumborum et thoracis depth (MLLT; mm), and backfat thickness (BT; mm) were assessed at 100 days of age. A dataset was created using the most current parental BVs for each year (2007–2014) and subsequent growth traits of their lambs in the next season (2008–2015). Linear regressions showed an increased tendency when one point in dam BVs was associated with an increase in lamb LW (0.393 kg; P &lt; 0.01 in BVLW-DE and 0.090 kg; P &lt; 0.05 in BVLW-ME), MLLT (0.340 mm; P &lt; 0.01 in BV-MLLT), or BT (0.243; P &lt; 0.01 mm in BV-BT). Lower (but significant – P &lt; 0.01) values on linear regression were detected for sire BVs, when 0.135 kg of LW, 0.217 mm of MLLT, and 0.214 mm of BT corresponded to 1-point increases of BVLW-DE, BV-MLLT, or BV-BT. This was confirmed by ANOVA evaluation, especially for LW and MLLT traits. Maximal differences (P &lt; 0.05) in lamb LW were 1.84 kg or 0.88 kg regarding to dam or sire BVLW-DE groups. Similarly, the difference (P &lt; 0.05) in lamb MLLT reached 0.82 mm in dam BV-MLLT, while 0.57 mm was detected in sire BV-MLLT groups. These results have practical implications for the objectives of selection schemes used in the Suffolk sheep population in the Czech Republic.

A Rare Case of False Positive in a Yeast Two-Hybrid Screening: The Selection of Rearranged Bait Constructs That Produce a Functional Gal4 Activity

1998 ◽  
Vol 262 (1) ◽  
pp. 94-96 ◽  
Author(s):  
Hakim El Housni ◽  
Isabelle Vandenbroere ◽  
David Perez-Morga ◽  
Daniel Christophe ◽  
Isabelle Pirson
Keyword(s):  
False Positive ◽  
Rare Case ◽  
Yeast Two Hybrid ◽  
Two Hybrid ◽  
Hybrid Screening ◽  
Selection Of
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