Short-term Progeny Tests and Second Generation Breeding in Slash Pine

1973 ◽  
Vol 3 (2) ◽  
pp. 165-169
Author(s):  
E. C. Franklin ◽  
A. E. Squillace
Keyword(s):  
First Generation ◽  
Second Generation ◽  
Slash Pine ◽  
Mass Selection ◽  
Progeny Testing ◽  
Family Selection ◽  
Short Term ◽  
Major Disadvantage ◽  
Selection For ◽  
Almost All

Progeny testing is the most widely used method for intensive genetic evaluation of selected forest trees, but its major disadvantage is the length of time needed to get results. To circumvent this problem in selection for a multiproduct strain of slash pine (Pinuselliottii Engelm.), a system for short-term (3-year) progeny testing was developed. Oleoresin yields of selected second-generation 19-year-old parent trees were compared with yields of their 3-year-old offspring. Both parents and offspring showed little variation and a low offspring–parent correlation (r = 0.18), but other traits based on the same parent trees when they were 25 years old and their 3-year-old offspring showed relatively large amounts of variation and moderate to strong offspring-parent correlations: height, r =.56; volume, r = 0.43; turpentine, r = 0.71; ethanol–benzene extractives, r = 0.38; specific gravity, r = 0.43; moisture content, r = 0.34. Thus, indications are that additional gains could be made in the first generation by selecting among parent trees on a progeny performance basis in all traits except oleoresin yield. Original mass selection for oleoresin yield achieved gains of 100% improvement and apparently exploited almost all of the genetic variation in the base population. In second generation selection, progeny testing will be used primarily in screening for fusiform rust resistance. Between-family plus within-family selection will be used for other traits.

Genetics and breeding of Sitka spruce

1987 ◽  
Vol 93 (1-2) ◽  
pp. 41-50
Author(s):  
Roy Faulkner
Keyword(s):  
Phenotypic Selection ◽  
Sitka Spruce ◽  
Interspecific Hybridisation ◽  
Family Selection ◽  
Short Term ◽  
Improvement Programme ◽  
Important Trait ◽  
Clonal Testing ◽  
Selection For ◽  
Old Trees

SynopsisSitka spruce is a monoecious, wind-pollinated, cross-fertilising species showing wide genetic variation which suggests heterozygosity for many alleles and natural selection against self-fertilisation. Phenotypic selection for the important trait of vigour is ineffective, so testing progenies of selected individuals and clonal testing is an essential and time-consuming part of any improvement programme. Old trees can be vegetatively propagated by grafting and very young trees by rooted cuttings.The British tree improvement programme is based, in the short term, on the use of seed collected from superior plantation trees of desirable origins; in the mid term on seed derived from clonal orchards based on mixtures of clones previously tested for superiority in family tests; and in the longer term on highly superior seed or clones derived from a system of recurrent mating with family selection. Three populations are being developed. There is a small interspecific hybridisation programme.

MASS SELECTION FOR RESISTANCE TO SELENOPHOMA BROMIGENA IN NORTHERN AND SOUTHERN TYPES OF BROMUS INERMIS

1967 ◽  
Vol 47 (6) ◽  
pp. 679-681 ◽  
Author(s):  
J. Drew Smith ◽  
R. P. Knowles
Keyword(s):  
Disease Resistance ◽  
Leaf Spot ◽  
Bromus Inermis ◽  
Mass Selection ◽  
Progeny Testing ◽  
Smooth Bromegrass ◽  
Selection For ◽  
Better Than

In the epidemic years 1965 and 1966, field ratings confirmed that southern strains of smooth bromegrass, Bromus inermis Leyss, were generally less susceptible to leaf spot caused by Selenophoma bromigena (Sacc.) Sprague & A. G. Johnson than northern strains. The northern/southern hybrid S-6733, developed by mass selection and progeny testing, was found to resist S. bromigena at least as well as the southern strains Lincoln and Redpatch, and better than the southern Saratoga. It was found possible to improve resistance of the susceptible northern strain Carlton by mass selection. Northern strains probably do not have as great a potential for improvement in disease resistance as southern strains or hybrids.

scholarly journals Two-way within-family and mass selection for 8-week body weight in different mouse populations

1984 ◽  
Vol 43 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Ines von Butler ◽  
Henning Willeke ◽  
Franz Pirchner
Keyword(s):  
Body Weight ◽  
Inbred Strains ◽  
Selection Response ◽  
Mass Selection ◽  
Individual Selection ◽  
Family Selection ◽  
Body Weights ◽  
Selection For ◽  
Size At Birth ◽  
Better Than

SUMMARYTwo mouse populations, randombred albino mice and a cross of four inbred strains, were divergently selected for high (H8) and low (L8) 8-week body weight over 18 generations using within-family and individual selection. The crossbreds showed asymmetry of selection response and realized heritabilities (H8 0·29 ± 0·01; L8 0·17 ± 0·01). In the randombred population realized heritabilities were symmetrical (H8 0·23 ± 0·01; L8 0·22 ± 0·02). Over the first nine generations individual selection was nearly 40 per cent better than within-family selection, as was expected from the full sib correlation in both populations. As selection progressed, within-family selection reached 82% and 61% of the responses obtained with individual selection in the crossbreds and randombred respectively. Correlated responses for 3-week (weaning) and 5-week body weights agreed with observations made on direct responses, but selection for L8 did not reduce weaning weight. Selection for L8 decreased and selection for H8 increased first litter size at birth. However, mass-selected L8-pairs had a higher life-reproduction and life-span than H8-pairs.

Clinical validation of a second-generation fructosamine assay

1991 ◽  
Vol 37 (7) ◽  
pp. 1252-1256 ◽  
Author(s):  
William T Cefalu ◽  
Audrey D Bell-Farrow ◽  
Marie Petty ◽  
Camille Izlar ◽  
Jeffrey A Smith
Keyword(s):  
Glycemic Control ◽  
Intervention Program ◽  
First Generation ◽  
Second Generation ◽  
Blood Glucose Concentration ◽  
Diabetic Patients ◽  
Short Term ◽  
Insulin Dependent ◽  
The One ◽  
Insulin Dependent Diabetic

Abstract The serum fructosamine assay, used to monitor short-term clinical glycemic control, reportedly has several technical drawbacks. However, technical improvements have resulted in a new second-generation assay of fructosamine. We evaluated this second-generation assay (from Roche Diagnostics) in 529 nondiabetic and diabetic patients and found a highly significant correlation with results of the first-generation assay (r = 0.91, P less than 0.001). Use of the second-generation assay with samples from patients classified on the basis of glycemic control according to their glycohemoglobin (GHb) values, enabled us to discriminate between the nondiabetics, diabetics with "good/moderate" control (i.e., GHb less than 10%), and diabetics with "poor" control (GHb greater than or equal to 10%). We evaluated the validity of the second-generation assay to assess short-term glycemic control in 23 non-insulin-dependent diabetic patients who participated for 10 weeks in an intensive intervention program designed to rapidly normalize the clinical glycemic profile. Results correlated significantly with the one-week average capillary blood glucose concentration (CBG) and with the three-week average CBG in all 23 patients. In addition, the second-generation fructosamine assay results demonstrated a significant decrease at each week of study, as did the average CBG. Results of the first- and second-generation assays correlated significantly at each week of study. GHb correlated significantly with both the second- (r = 0.78, P less than 0.001) and first-generation fructosamine assay results (r = 0.77, P less than 0.001) for the baseline blood samples of the intervention study, but this correlation decreased (to r = 0.35, P = 0.09 and r = 0.34, P = 0.09, respectively) by the conclusion of the study.

EARLY GENERATION SELECTION FOR PROTEIN IN Glycine max × G. soja CROSSES

1981 ◽  
Vol 61 (4) ◽  
pp. 901-908 ◽  
Author(s):  
L. R. ERICKSON ◽  
W. D. BEVERSDORF ◽  
H. D. VOLDENG
Keyword(s):  
Protein Content ◽  
Seed Protein ◽  
Glycine Soja ◽  
Mass Selection ◽  
Seed Protein Content ◽  
Family Selection ◽  
Early Generation ◽  
Early Generation Selection ◽  
The Mean ◽  
Selection For

Early generation selection for high seed-protein content would be desirable in breeding programs attempting to combine high yield and high protein content in soybeans (Gycine max (L.) Merr.). The heritability of seed-protein content in the F2 and F3 was measured in four crosses and mass and family selection for protein were compared in the F3 of these crosses. Glycine soja Sieb. and Zucc., a putative wild ancestor of the soybean, was the male parent in all crosses and selection intensity was at 10%. The heritability of protein in the F2, calculated by parent-offspring regression, was 27%. The broad-sense heritability of protein in F3 families grown over two locations in one season was 78%. Mean protein content for every selected population was greater (P ≤ 0.01) than the mean for the non-selected control population (45.3%). Mean protein contents of the F4 populations resulting from these selection methods were: mass selection in the F2 and F3, 48.0%; mass selection in the F3 following one generation of single seed descent, 48.8%; selection among F3 families, 47.6%; selection among and within F3 families, 47.5%. Either method of mass selection was superior to either method of family selection at the 0.01 level. Although early selection (mass or family) raised the mean protein content of a population, segregation continued to give rise to low-protein genotypes thereby requiring further selection.

scholarly journals RESPONSE TO SELECTION FOR BODY WEIGHT IN THE THIRD GENERATION OF MASS SELECTION OF THE AFRICAN CATFISH (Clarias gariepinus) AT RESEARCH INSTITUTE FOR FISH BREEDING SUKAMANDI

2016 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Bambang Iswanto ◽  
Imron Imron ◽  
Huria Marnis ◽  
Rommy Suprapto
Keyword(s):  
Body Weight ◽  
Second Generation ◽  
Clarias Gariepinus ◽  
Mass Selection ◽  
African Catfish ◽  
Larval Rearing ◽  
Third Generation ◽  
Response To Selection ◽  
The Third ◽  
Selection For

Genetic improvement of the African catfish (Clarias gariepinus) in Indonesia for increasing growth performance has been conducted by Research Institute for Fish Breeding at Sukamandi through mass selection. Collection and characterizations of the founder populations, building the synthetic base population, first generation and second generation through mass selection were conducted during 2010-2013. Later, in 2014 it was followed by building the third generation. The present study aimed to find out the genetic gain in the third generation in term of response to selection for body weight. Fifty-two pairs of the selected (fast growing) individuals from the second generation were mated to produce the third generation. As a comparison, five pairs of average-sized individuals were mated to produce the control population, as a second generation representative. Larval rearing, nursery and grow-out phases were respectively held for 25 days in the aquaria, 30 days in the concrete ponds and 60 days in the concrete ponds. At the end of each phase, individual samplings of body weight were undertaken. The results showed that mean body weight of the third generation was higher than that of control population at the end of larval rearing phase (0.21 ± 0.26 g versus 0.20 ± 0.15 g), nursery phase (6.12 ± 2.93 g versus 5.80 ± 3.50 g) and grow-out phase (198.67 ± 82.82 g versus 165.22 ± 71.09 g). Those results revealed that response to selection for body weight of the third generation was positive, i.e. about 20.24% (33.45 g).

scholarly journals Genetic Variation in Growth Traits in a Quercus robur L. Open-Pollinated Progeny Test of the Slavonian Provenance

2004 ◽  
Vol 53 (1-6) ◽  
pp. 198-201 ◽  
Author(s):  
S. Bogdan ◽  
I. Katičić-Trupčević ◽  
D. Kajba
Keyword(s):  
Genetic Variation ◽  
First Generation ◽  
Population Variation ◽  
Progeny Test ◽  
Mass Selection ◽  
Progeny Testing ◽  
Pedunculate Oak ◽  
Genetic Gains ◽  
Family Effect ◽  
Productive Traits

Abstract The study presents evaluation of an open-pollinated progeny test of 21 selected plus trees from Slavonian pedunculate oak provenance in Croatia (in the central part of Drava river valley). The test was established in 1992 with two-year-old seedlings. Heights were measured at 5 to 13 years and diameters at breast height (DBH) at 10 to 13 years after sowing. Variances caused by the population within provenance effect were not significant during the studied period. In contrast, variance components caused by family effect were statistically significant, and ranged from 11.1 to 18.6% and from 2.2 to 10.6% for height and DBH respectively. Statistically significant variances caused by the family effect indicate that most of genetic variation of productive traits was within the studied populations. The estimated family mean narrow sense heritabilities varied from 0.62 to 0.78 and from 0.28 to 0.65, while individual heritabilities ranged from 0.48 to 0.80 and from 0.09 to 0.46 for height and DBH, respectively. Realised gain from the test and expected genetic gains by two possible methods of selection for the measured traits have been calculated for: i.) realised gain i.e. superiority of selected plus trees progenies over control plants (bulks from unselected trees within the provenance) ii.) individual within provenance mass selection of first generation plus trees at the same ages as those represented in studied trial and iii.) backward selection among first generation plus trees after open-pollinated testing. Estimated genetic gains indicate that the highest gain could be expected by backward selection among first generation plus trees after open-pollinated progeny testing (9.7 to 22.3% and 6.8 to 17.3% over control means). These results indicate that due to significant within population variation and high additive variances, improvement for productive traits in the studied oak populations could be achieved by use of seeds and plants from selected plus trees (especially from already established clonal seed orchard), at least in younger ages.

Selection for economic characters in Australian Merino sheep. II. Relative efficiency of certain aids to selection.

1952 ◽  
Vol 3 (4) ◽  
pp. 409 ◽  
Author(s):  
FHW Morley
Keyword(s):  
Artificial Insemination ◽  
Relative Efficiency ◽  
Mass Selection ◽  
Progeny Testing ◽  
Merino Sheep ◽  
Selection For ◽  
The Cost ◽  
Australian Merino

Theoretical consequences of the use of progeny testing, sib testing, and mass selection are examined in a flock of 1,000 ewes producing 700 progeny of breeding age each year. Selection based on a combination of individual merit and merit of half-sibs should result in approximately the same annual improvement as that achieved by optimum use of progeny-tested sires. In large flocks extensive use of outstanding sires by artificial insemination may increase progress for traits with heritability of about 0.3 by a factor of about 1.2 as compared with mass selection. The advantages to be gained by progeny testing and artificial insemination may be outweighed by the dangers of inbreeding, and the cost involved would have to be considered. As most of these advantages should be achieved by combination or even by mass selection, which avoid inbreeding and much of the cost, progeny testing with wide use of progeny-tested sires is unlikely to be the most economical road to flock improvement.

Quantitative inheritance studies in sugar-cane. II. Correlations and predicted responses to selection

1971 ◽  
Vol 22 (1) ◽  
pp. 103 ◽  
Author(s):  
DM Hogarth
Keyword(s):  
Sugar Cane ◽  
Standard Errors ◽  
Mass Selection ◽  
Quantitative Inheritance ◽  
Selection System ◽  
Family Selection ◽  
Genotypic And Phenotypic Correlations ◽  
Selection For ◽  
Genotypic Correlations ◽  
Brix Value

Predicted responses to selection for a number of characters, and genotypic and phenotypic correlations between characters were studied in sugar-cane seedling populations. Predicted response from family selection was found to be much greater than from mass selection for all characters except Brix value. A selection system incorporating family selection for grade (phenotypic score) and mass selection for Brix value was proposed for further investigation. Many genotypic correlations between important characters were positive and quite high with the notable exception of the correlation between stalks per stool and weight per stalk, which was high and negative. Genotypic correlations between arrowing percentage (an undesirable character) and all other characters except stalks per stool were high and negative, but most had large standard errors.

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