Nearest-neighbor-adjusted means as a selection criterion within two soybean populations

1995 ◽  
Vol 75 (4) ◽  
pp. 857-863 ◽  
Author(s):  
T. C. Helms ◽  
J. H. Orf ◽  
R. A. Scott
Keyword(s):  
Nearest Neighbor ◽  
Selection Criterion ◽  
Mean Square ◽  
Selection Environment ◽  
Adjusted Means ◽  
Glycine Max L ◽  
Selection For ◽  
Testing Environments ◽  
Actual Yield ◽  
Actual Gain

When the nearest-neighbor adjustment (NNA) reduces the magnitude of the residual mean square, plant breeders have the option of selecting genotypes on the basis of the NNA or unadjusted (UNADJ) means. The actual gain from selection for a specific set of experiments can be compared when selection is based on each criterion. Our objective was to compare the yields of lines selected with the NNA and UNADJ criteria. Three hundred soybean [Glycine max (L.) Merr.] experimental lines were evaluated in six environments. Each environment was considered a selection environment, and the actual yield advance was measured in the other five environments. In 11 out of 12 cases, the lines selected by the NNA and UNADJ criteria were equal in yield when compared in testing environments. Interlocation correlations were similar for both models. Predicted genetic gain was overestimated more often when using the NNA than the UNADJ model. Key words:Glycine max, heritability

Actual yield advance from selection for visual score and yield

1995 ◽  
Vol 75 (1) ◽  
pp. 187-189 ◽  
Author(s):  
T. C. Helms ◽  
J. H. Orf ◽  
R. A. Scott
Keyword(s):  
The Other ◽  
Selected Lines ◽  
Physiological Maturity ◽  
Population Mean ◽  
Visual Score ◽  
Glycine Max L ◽  
Unselected Population ◽  
Selection For ◽  
Testing Environments ◽  
Actual Yield

The ability of soybean [Glycine max (L) Merr.] breeders to select for yield, based on visual score is unknown. Our objectives were (i) to determine whether a sample of three breeders were able to visually score soybean plots for yield and to identify lines that were higher yielding than the population mean; and (ii) to compare selection for visual score versus selection solely for weighed yield. Visual score was rated at physiological maturity in two environments. Experimental lines were evaluated for weighed yield in six environments. Lines were selected for weighed yield or visual score, based on data from two selection environments, and actual yield advance was measured in the other four testing environments. Two breeders identified BP-derived lines that averaged higher than the unselected population mean yield when selection was based solely on the visual score. Two of three breeders selected lines, based on visual score, that were as high yielding in testing environments as lines selected solely for weighed yield. Key words: Soybean, visual score

scholarly journals Selection Criteria and Selection Environment for Drought Tolerance of Egyptian Wheat (Triticum aestivum L.) Landraces

2020 ◽  
pp. 25-40
Author(s):  
Ahmed Medhat Mohamed Al-Naggar ◽  
Mohamed Abd El-Maboud Abd El-Shafi ◽  
Mohamed Helmy El-Shal ◽  
Ali Hassan Anany
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Selection Criteria ◽  
Selection Criterion ◽  
Correlation Coefficients ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Genetic Advance ◽  
Selection Environment ◽  
Selection For

Strong correlations between wheat traits and drought tolerance (DT) associated with high heritability and high genetic advance from selection would allow plant breeder to use such traits as selection criteria. The objective of the present investigation was to determine the optimum selection criteria and selection environment for drought tolerance via estimation of correlation coefficients (r) among 13 agronomic, grain yield and quality traits and DT of 20 wheat landraces, broad-sense heritability (h2b) and genetic advance (GA) from selection for such traits under well-watered (WW) and water stressed (WS) environments. A two-year experiment was carried out using a split-plot design with four replications. Results concluded that the best selection criterion for drought tolerance in our study was grain yield/plant (GYPP), followed by a number of grains/spike (GPS), grain filling period (GFP), grain starch (GSC) and protein (GPC) content, plant height (PH) and days to maturity (DTM), since they showed high (r), high h2b and high GA estimates. The best selection environment was WW for days to anthesis, PH, spikes/plant, GPS, spikelets/spike, GYPP, GPC and WS for DTM, GFP, GSC and thousand-grain weight traits. This information could help future breeding programs in selection for improving drought tolerance of wheat.

scholarly journals Hotel Selection Criteria of Solo Traveling Females

2020 ◽  
Vol 18 (2) ◽  
pp. 58-73
Author(s):  
Halimin Herjanto ◽  
◽  
Alexandra Chilicki ◽  
Chidchanok Anantamongkolkul ◽  
Erin McGuinness ◽  
...  
Keyword(s):  
Cell Phone ◽  
Selection Criteria ◽  
Academic Research ◽  
Selection Criterion ◽  
Product Evaluations ◽  
Purchasing Decisions ◽  
Study Results ◽  
Automated Teller Machine ◽  
Selection For ◽  
Cost Efficient

Consumers use online e-reviews as a popular tool for information and obtaining guidance. E-reviews have therefore become an important barometer in conducting product evaluations, and more importantly, to make purchasing decisions. This includes decisions about hotel selection. For hospitality industry marketers, the information in e-reviews is particularly important in translating and understanding consumer-specific needs. The current study brings valuable awareness to the limited academic research into hotel selection criteria among solo-traveling females. TripAdvisor’s top 25 list of cost-efficient hotels worldwide received 345 total consumer reviews. Noteworthy findings of the current study show unique selection criteria considered important to the solo traveling female including a hotel-provided cell phone programmed with emergency local contact information, and a nearby or on-premise automated teller machine. Study results also indicate that stewardship service, such as intimate and personalized hotel staff who “go the extra mile” is an important selection criterion. Also discussed are research limitations and implications.

scholarly journals Variability, Heritability, Genetic Advance and Interrelationships for Agronomic and Yield Traits of Sorghum B-Lines under Different Environments

2018 ◽  
pp. 1-13
Author(s):  
A. M. M. Al-Naggar ◽  
R. M. Abd El-Salam ◽  
M. R. A. Hovny ◽  
Walaa Y. S. Yaseen
Keyword(s):  
Grain Yield ◽  
Coefficient Of Variation ◽  
Block Design ◽  
Selection Criterion ◽  
Genetic Advance ◽  
Planting Dates ◽  
High Heritability ◽  
Selection For ◽  
Strength Of Association ◽  
B Lines

Information on heritability and trait association in crops assist breeders to allocate resources necessary to effectively select for desired traits and to achieve maximum genetic gain with little time and resources. The objectives of this investigation were to determine the amount of genetic variability, heritability, genetic advance and strength of association of yield related traits among sorghum lines under different environments in Egypt. Six environments with 25 sorghum B-lines were at two locations in Egypt (Giza and Shandaweel) in two years and two planting dates in one location (Giza). A randomized complete block design was used in each environment with three replications. Significant variation was observed among sorghum lines for all studied traits in all environments. Across environments, grain yield/plant (GYPP) showed positive and significant correlations with number of grains/plant (r = 0.71), days to flowering (r = 0.47), 1000-grain weight (r = 0.16) and plant height (PH) (r = 0.19). In general, the estimates of phenotypic coefficient of variation (PCV) were higher than genotypic coefficient of variation (GCV). Combined across the six environments, the highest PCV and GCV was shown by PH trait (95.14 and 43.57%) followed by GYPP (36.42 and 30.78%), respectively, indicating that selection for high values of these traits of sorghum would be effective. GYPP and PH traits showed high heritability associated with high genetic advance from selection, indicating that there are good opportunities to get success in improvement of these traits via selection procedures. Results concluded that PH is good selection criterion for GYPP and therefore selection for tall sorghum plants would increase grain yield.

scholarly journals Selection for growth on normal and reduced protein diets in mice: I. Direct and correlated responses for growth

1987 ◽  
Vol 50 (1) ◽  
pp. 7-15 ◽  
Author(s):  
B. Vivi Hunnicke Nielsen ◽  
Søren Andersen
Keyword(s):  
Protein Level ◽  
Protein Diet ◽  
Correlated Response ◽  
Family Selection ◽  
Direct Response ◽  
Protein Levels ◽  
Selection Environment ◽  
Normal Protein Diet ◽  
Selection For ◽  
Protein Diets

SummaryMice were selected for growth from 3 to 9 weeks of age on a normal protein diet (N) containing 19·3% protein and a reduced protein diet (R) containing 5·1% protein. On each diet there were 3 high (H), 3 low (L) and 3 unselected control (C) lines. After 6 generations of selection, half of the mice in each line were tested on each diet. Responses were obtained when selecting for both increased and decreased growth on both diets. The realized heritabilities from within-family selection were 33 and 26% for the divergences on the normal and reduced protein diets, respectively. Consistent genotype-environment interactions were found when all lines were tested on both diets in generation 7. Performance on each protein level was best improved by selection on that protein level. Further, the correlated response was significantly less than the direct response when selecting on both diets. The estimates of the genetic correlation between growth on the two protein levels were low, rN = 0·16 from selection on the normal protein diet and rR = 0·51 from selection on the reduced protein diet. Selection resulted in a change in environmental sensitivity in the lines, dependent on the diet and direction of selection. The average of the divergences on the two diets was not dependent on the selection environment.

Estimation of phenotypic selection differentials for predicting genetic responses to ratio-based selection

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 838-843 ◽  
Author(s):  
D. E. Mather ◽  
F. C. Gunsett ◽  
O. B. Allen ◽  
L. W. Kannenberg
Keyword(s):  
Selection Criteria ◽  
Crop Improvement ◽  
Selection Criterion ◽  
Phenotypic Selection ◽  
Worked Examples ◽  
Genetic Response ◽  
Analysis And Evaluation ◽  
Selection For ◽  
Genetic Responses ◽  
Selection Differentials

Ratios of the phenotypic values of two traits may be used as selection criteria in animal and plant breeding to improve the ratio traits themselves or to effect changes in their two component (numerator and denominator) traits. Prediction of genetic responses to ratio-based selection would facilitate quantitative analysis and evaluation of selection based on ratios. Methods for predicting such responses are derived and presented here. They employ expressions for the truncation value of a ratio and for the phenotypic selection differentials of the numerator and denominator traits. The derivation of these expressions is based upon the assumption that the phenotypic values of each of these traits are normally distributed. Worked examples relating to livestock and crop improvement are included to demonstrate how responses to selection for ratios may be predicted.Key words: ratio selection criterion, selection differential, genetic response.

Seed coat specific weight in Lupinus angustifolius: influence of genotype and environment and relationship with seed coat proportion

2004 ◽  
Vol 55 (11) ◽  
pp. 1189 ◽  
Author(s):  
M. Mera ◽  
R. Jerez ◽  
H. Miranda ◽  
J. L. Rouanet
Keyword(s):  
Seed Coat ◽  
Seed Weight ◽  
Mass Density ◽  
Selection Criterion ◽  
Specific Weight ◽  
Equal Mass ◽  
Lupinus Angustifolius ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Selection For

Abstract. The relatively high seed coat proportion of the narrow-leafed lupin reduces its economic value. This character has been shown to be affected by seed weight, and this limits the use of seed coat proportion as a selection criterion. We examined the variation for seed coat specific weight, a potential alternative selection criterion, and tested its relationship with seed coat proportion and seed weight. Seeds were sampled from mainstem pods of 14 winter-sown genotypes of Lupinus angustifolius L. grown at 4 southern Chile sites over 2 years. Seed coat specific weight had an overall mean of 30.1 mg/cm2. Highly significant genotypic effects were found (range 28.9–32.1 mg/cm2). The ranges for sites and years were 29.1–31.1 and 28.9–31.2 mg/cm2, respectively. Genotypes interacted significantly with years, but not with sites. Broad-sense heritability was 0.59, a value that predicts a good response to selection for this character. Seed coat specific weight was weakly correlated (rph = 0.11*) with seed coat proportion, and was not associated with mean seed weight. Seed coat proportion was negatively correlated with mean seed weight (rph = –0.75***) and had high broad-sense heritability (0.95). The correlation between seed coat specific weight and a theoretical seed coat thickness, calculated under the assumptions of equal mass density of seed coat, cotyledons, and embryo, and a spherical-shaped seed, was r = 0.14*. Phenotypic and genotypic correlations between seed coat specific weight and number of seeds per pod were 0.41 and 0.84, respectively. Our results indicate that selection for low seed coat proportion will lead to larger seeded genotypes, but will not reduce seed coat specific weight. Selection for low seed coat proportion after crosses would presumably be effective in reducing seedcoat specific weight if all segregating materials were uniformly large seeded, but that scenario is unrealistic. The evidence presented here suggests that selection for low seed coat specific weight (or measures correlated with it) in segregating populations will be necessary in order to increase the proportion of higher value kernels in seeds and to improve the economic yield of lupins.

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