Genetic gain from selection for rooting ability and early growth in vegetatively propagated clones of loblolly pine

2006 ◽  
Vol 3 (3) ◽  
pp. 227-238 ◽  
Author(s):  
Brian S. Baltunis ◽  
Dudley A. Huber ◽  
Timothy L. White ◽  
Barry Goldfarb ◽  
Henry E. Stelzer
Keyword(s):  
Loblolly Pine ◽  
Genetic Gain ◽  
Early Growth ◽  
Rooting Ability ◽  
Selection For

Genetic parameters and responses to selection for pre-weaning growth in suffolk and texel sheep

1995 ◽  
Vol 1995 ◽  
pp. 48-48
Author(s):  
I.W. Purvis ◽  
J.P. Hanrahan
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Genetic Gain ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Present Report ◽  
Growth Data ◽  
Genetic Trend ◽  
Breeding Objective ◽  
Selection For

In order to evaluate genetic gain in populations under selection it is necessary to be able to partition the observed response into genetic and environmental components. This requires estimates of the appropriate genetic and environmental (co)variances unless appropriate genetic controls are available. Growth rate is an important component of the breeding objective for sheep breeds used as terminal sires and, whereas older estimates of the contribution of genetic variation to differences in preweaning growth indicated heritabilities of the order of 0.1, more recent studies have indicated considerably higher values. The present report concerns analyses of preweaning growth data on purebred Suffolk and Texel sheep to estimate genetic parameters for preweaning growth traits and genetic trend in growth rate from birth to weaning.

Sewage Sludge Increases Early Growth and Decreases Fusiform Rust Infection of Nursery-Run and Rust-Resistant Loblolly Pine

1989 ◽  
Vol 13 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Douglas M. Stone ◽  
Harry R. Powers
Keyword(s):  
Sewage Sludge ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Early Growth ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
First Year ◽  
Average Height ◽  
Fusiform Rust ◽  
Rust Infection

Abstract An intensively prepared site in a high-rust hazard area was fertilized with municipal sewage sludge to provide 300 or 600 lb/ac total nitrogen before planting nursery-run and fusiform rust-resistant seedlings. Rust-resistant seedlings had significantly greater first-year survival andsignificantly lower rust infection at age 6. The sludge treatments increased 6-year diameter and volume growth and decreased rust infection significantly; there were no differences between the two sludge levels. Sludge fertilization significantly increased average height, diameter, and stemvolume of the largest 300 trees/ac and has begun to stimulate crown class differentiation. The greater growth of the larger trees did not alter the proportion infected by rust. Results indicate that even in areas of high-rust hazard, intensive site preparation and sludge fertilization canincrease early growth and accelerate stand development of loblolly pine if rust-resistant stock is planted. South J. Appl. For. 13(2):68-71.

Environmental and genetic variation for grain yield and barley malting quality attributes

1999 ◽  
Vol 50 (8) ◽  
pp. 1425 ◽  
Author(s):  
M. Q. Lu ◽  
L. O'Brien ◽  
I. M. Stuart
Keyword(s):  
Grain Yield ◽  
Protein Content ◽  
Genetic Gain ◽  
Quality Attributes ◽  
Malting Quality ◽  
Malt Extract ◽  
Progeny Testing ◽  
Environment Interaction ◽  
Wide Range ◽  
Selection For

Genotype, environment, and genotype × environment interaction effects for malting quality attributes and grain yield were investigated using breeding lines from the F2, F3, and F4 generations and the parental varieties of 4 barley crosses. There were significant differences between the parental varieties for all attributes studied. Both malting quality and grain yield exhibited a wide range among progenies in all generations. While performance of the parental varieties and progeny for malting quality and grain yield were greatly influenced by environment, performance in one environment was predictive of that in other environments. Only for grain protein content was there evidence of crossover G × E interaction. Heritability was generally higher for F3 to F4 than for F2 to F3 for all malting quality attributes. F3 on F2 regression per cent heritability estimates for protein content, potential malt extract and grain weight were all highly significant with values generally medium in magnitude. Genetic gain was obtained from selection in both the F2 and F3 generations. Heritability and genetic gain varied from cross to cross for diastatic power. Progress from selection for the other quality attributes attests to the potential value of NIT (near infrared transmittance) spectroscopy for predicting potential malting quality. Heritability for F2 to F3 for grain yield was not significant in any cross, indicating selection for yield on the basis of individual F2 plant yield was ineffective. Heritability for grain yield from F3 to F4 was highly significant and medium in magnitude for 3 of the 4 crosses. The results of this study indicate that good genetic gain could be expected from early generation selection for potential malting quality using NIT spectroscopy and for grain yield using F3 progeny testing.

Effect of nursery conditioning treatments and fall fertilization on survival and early growth of Pinus taeda seedlings in Alabama, U.S.A.

2002 ◽  
Vol 32 (7) ◽  
pp. 1171-1179 ◽  
Author(s):  
David B South ◽  
D GM Donald
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Experimental Error ◽  
Early Growth ◽  
Cool Storage ◽  
Reduced Height ◽  
Error Terms ◽  
Bare Root ◽  
Pinus Taeda L

Four seedling conditioning treatments and four fall fertilization treatments were applied to loblolly pine (Pinus taeda L.) seedlings in a bare-root nursery in Alabama. Three conditioning treatments involved undercutting plus root wrenching (two, four, and six times), and a fourth treatment included top-pruning (three times) and no undercutting. Fertilizer treatments consisted of (i) control, (ii) 150 kg/ha of N, (iii) 150 kg/ha of N plus 150 kg/ha of P, and (iv) 150 kg/ha of K. On two sites, seedlings were planted in November, and an equal number were placed in cool storage and planted 6 weeks later in mid-December. Results 5 years after outplanting were generally similar for both sites; however, experimental error terms were higher on the sandy site. As a result, conditioning and fertilizer treatments had a statistically significant effect on volume per hectare at the loamy site but not at the sandy site. Volume per hectare was enhanced by undercutting in August followed by two root wrenchings and fall fertilization with N plus P. Storing seedlings reduced height, groundline diameter, and volume per hectare at both sites and reduced survival at the loamy site. Survival of both freshly planted and stored seedlings was greater than 71% at both sites.

scholarly journals The Effect of Selection for Early Growth on the Market Grades of Turkeys

1970 ◽  
Vol 49 (1) ◽  
pp. 150-154 ◽  
Author(s):  
G.W. Friars ◽  
M.L. Tiku
Keyword(s):  
Early Growth ◽  
Selection For

Genetic response to within-family selection using molecular markers in some radiata pine breeding schemes

2001 ◽  
Vol 31 (5) ◽  
pp. 779-785 ◽  
Author(s):  
Satish Kumar ◽  
D J Garrick
Keyword(s):  
Genetic Gain ◽  
Radiata Pine ◽  
Forest Tree ◽  
Clonal Forestry ◽  
Genetic Response ◽  
Forest Tree Breeding ◽  
Forward Selection ◽  
Family Selection ◽  
Marker Haplotype ◽  
Selection For

Marker-assisted selection (MAS) provides an opportunity to increase the efficiency of within-family selection in forest tree breeding. Within-family MAS involves selection decisions first made on conventional breeding values and quantitative trait loci (QTL) information used for within-family selection. In this study genetic response obtained by using MAS was compared with conventional methods for three options: "full-sib family forestry," "clonal forestry," and "forward selection for deployment." This comparison was undertaken using stochastic simulation for a locus that explained 10 or 20% of the genetic variance. In the full-sib family forestry scenario, markers were used to select genotypes (among juvenile individuals in a family) for vegetative propagation. Markers were used to preselect genotypes for clonal testing in clonal forestry option. In case of forward selection for deployment option, offspring that have favourable marker haplotype and a superior phenotype were selected from each family. The comparison between the MAS and the conventional strategy was evaluated in genetic terms based on comparison of the average genetic merit of the genotypes used for deployment in production plantations. The relative genetic gain (%) using MAS were found to be 4–8% and 2–3% higher compared with conventional strategy for full-sib family forestry and clonal forestry options, respectively. In case of forward selection for deployment option, MAS was generally found to be providing higher genetic gain only when the heritability is low.

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