AN APPLICATION OF INDEX SELECTION TO THE IMPROVEMENT OF SELF-POLLINATED SPECIES

1970 ◽  
Vol 50 (3) ◽  
pp. 267-276 ◽  
Author(s):  
J. PESEK ◽  
R. J. BAKER
Keyword(s):  
Triticum Aestivum ◽  
Selection Index ◽  
Triticum Aestivum L ◽  
Hybrid Population ◽  
Index Selection ◽  
Index Method ◽  
Quantitative Characters ◽  
Economic Weights ◽  
Selection For ◽  
Genotypic Effects

Results of a genetic study of four quantitative characters in a cross of two cultivars of Triticum aestivum L. em Thell. indicated that heritability of yield was lower than the heritabilities of maturity and height and that interactions between genotypic effects and year environmental effects were nonsignificant. The modified selection index method, based upon desired genetic gains rather than relative economic weights of traits, is explained in detail and applied to selection for maturity, height and yield from a hybrid population of wheat. The methods and problems of using index selection in self-pollinated species are discussed.

SELECTION FOR YIELD, KERNEL WEIGHT AND PROTEIN CONTENT IN EARLY GENERATIONS OF SIX WHEAT CROSSES

1988 ◽  
Vol 68 (3) ◽  
pp. 641-649 ◽  
Author(s):  
H. GEBRE-MARIAM ◽  
E. N. LARTER ◽  
L. E. EVANS
Keyword(s):  
Triticum Aestivum ◽  
Protein Content ◽  
Selection Index ◽  
Correlation Coefficients ◽  
Triticum Aestivum L ◽  
Kernel Weight ◽  
High Protein ◽  
Selection Indices ◽  
Different Populations ◽  
Relative Potential

Early generation data consisting of F1 heterosis, F1, F2 and F3 mean performances, parent-offspring regression, and F2–F3 intergeneration correlation were used to identify potentially promising spring wheat (Triticum aestivum L. em Thell) crosses in terms of yield, kernel weight and protein content. The F1 test identified one high-yielding cross out of six showing significant level of higher parent (38%) and mid-parent (70%) heterosis for yield, respectively. The top yielding cross, viz. Glenlea × NB505, in F1 was also the second highest yielding population in F2 and the best yielder in F3 based on two locations. Hence, although F2 single plant productivity measurements misplaced the rankings of some of the crosses, F1 and F3 performances indicated the relative potential of the different populations. Most crosses showed nonsignificant F2–F3 regression and correlation coefficients for yield but significant coefficients for kernel weight. For protein content highly significant F2–F3 regression and correlation coefficients were observed only for crosses involving the high protein parent. The use in F1 of weight-free selection indices involving yield, kernel weight and protein content ranked Glenlea × NB505 as the best of six populations whereas in F3 the same cross had the best aggregate merit when only yield and kernel weight were considered in the index. The inclusion of protein content in the index favored a high protein cross, Sinton × Glenlea.Key words: Wheat, Triticum aestivum, heterosis, parent-offspring regression, intergeneration correlation, selection index

Relative economic importance of some wool quality traits for Merino and crossbred wool types

1970 ◽  
Vol 10 (46) ◽  
pp. 544 ◽  
Author(s):  
PD Mullaney ◽  
ID Sanderson
Keyword(s):  
Selection Index ◽  
Fibre Diameter ◽  
Economic Importance ◽  
Quality Traits ◽  
Regression Analyses ◽  
Independent Variables ◽  
Economic Weights ◽  
Australian Wool ◽  
The Mean ◽  
Selection For

The economic weights of various quality traits of both Merino and crossbred wool types hive been estimated. Australian averages of clean wool prices for Australian Wool Board wool types, into which mid-side samples of fleece were classified, have been used.For each of fifteen seasons, 1953-54 to 1967-68, the mean clean wool price for each wool type was expressed as a percentage of the mean wool price for all types in that season. Rank correlations for price-type means were high between seasons, varying between 0.91 and 0.98. Further analyses were therefore performed using prices averaged for the 15 seasons. Multiple regression analyses were carried out, the dependent variable being the mean price for each fleece type, expressed as a percentage of the average price of all types for al) seasons and the independent variables being the measurement of fibre diameter, crimps per inch and length, and the subjective gradings of colour, handle, character, and quality number. For both Merino and crossbred wool types, the major determinants of price were quality number, colour, and handle, with quality number being of overwhelming importance. The remaining variables were not important as joint determinants of price, and were deleted from the analyses. Quality number, colour, and handle controlled about 81 and 86 per cent of the variation in price for Merino and crossbred wool types. It is likely that most progress in selection for wool production would be made by incorporating these findings into a selection index.

Effect of index selection in GGP lines on cocoon traits of silkworm commercial hybrids

2007 ◽  
Vol 2007 ◽  
pp. 68-68
Author(s):  
Mani Ghanipour ◽  
Seyed Ziaeddin Mirhosseini ◽  
Abdol Ahad Shadparvar ◽  
Alireza Seidavi ◽  
Alireza Bizhannia
Keyword(s):  
Production System ◽  
Egg Production ◽  
Selection Index ◽  
Index Selection ◽  
Genetic Trend ◽  
Index Method ◽  
Chinese Origin ◽  
Maximum Improvement ◽  
Parent Stock ◽  
High Selection

The general aim of selection in animal breeding is to acquire new generation of animals, which under future economic conditions of production system are more efficient than the present generation. In selection index method, genetic trend of important traits is directed based on their weights in economic efficiency of production system to acquire maximum improvement in economic merit (Mirhosseini et al., 2005). Silkworm commercial egg is produced by crossing between Japanese and Chinese origin parent stocks. There are three steps in the cycle of egg production including GGP (great grand parent), GP (grand parent) and P (parent stock). Breeding programs along with high selection pressure are used only in GGP lines which are typically much smaller in size than other stocks. The objective of this study was to evaluate effect of six generations of index selection in the GGP lines on performance of commercial silkworm hybrids.

scholarly journals Recurrent selection for wider seedling leaves increases early biomass and leaf area in wheat (Triticum aestivum L.)

2014 ◽  
Vol 66 (5) ◽  
pp. 1215-1226 ◽  
Author(s):  
L. Zhang ◽  
R. A. Richards ◽  
A. G. Condon ◽  
D. C. Liu ◽  
G. J. Rebetzke
Keyword(s):  
Triticum Aestivum ◽  
Leaf Area ◽  
Recurrent Selection ◽  
Triticum Aestivum L ◽  
Selection For

COMPARISON OF PREDICTED AND OBSERVED RESPONSES TO SELECTION FOR YIELD IN WHEAT

1971 ◽  
Vol 51 (3) ◽  
pp. 187-192 ◽  
Author(s):  
J. PESEK ◽  
R. J. BAKER
Keyword(s):  
Triticum Aestivum ◽  
Common Wheat ◽  
Triticum Aestivum L ◽  
Standard Errors ◽  
Selection Differential ◽  
Response To Selection ◽  
Simple Method ◽  
Different Populations ◽  
Selection For ◽  
Heritability Estimates

A simple method of calculating standard errors of heritability estimates is presented. The method is then used to conclude that observed response to selection for yield in five different populations of common wheat, Triticum aestivum L., agreed with the response predicted by multiplying estimates of heritability by the selection differential. It is suggested that a comparison of observed and predicted responses is not the best way to test the theory used in predicting response to selection.

Impacts of Selection for Spike Length on Heat Stress Tolerance in Bread Wheat (Triticum aestivum L.)

2019 ◽  
Vol 7 (2) ◽  
pp. 83-94
Author(s):  
Asmaa M. Mohamed ◽  
Mohamed K. Omara ◽  
Mahmoud A. El-Rawy ◽  
Mohamed I. Hassan
Keyword(s):  
Triticum Aestivum ◽  
Heat Stress ◽  
Stress Tolerance ◽  
Bread Wheat ◽  
Triticum Aestivum L ◽  
Spike Length ◽  
Heat Stress Tolerance ◽  
Selection For

EFFECT OF WEATHERING DURING DELAYED HARVEST ON TEST WEIGHT, SEED SIZE, AND GRAIN HARDNESS OF WHEAT

1986 ◽  
Vol 66 (3) ◽  
pp. 473-482 ◽  
Author(s):  
E. CZARNECKI ◽  
L. E. EVANS
Keyword(s):  
Weight Loss ◽  
Triticum Aestivum ◽  
Seed Size ◽  
Triticum Aestivum L ◽  
Test Weight ◽  
Grain Hardness ◽  
Kernel Weights ◽  
Selection For ◽  
Packing Efficiency ◽  
Harvest Delay

Five cultivars of wheat (Triticum aestivum L.) were evaluated for effects of weathering by subjecting windrowed grain to varying periods of exposure in a 2-yr study. Moderate amounts of precipitation caused a significant reduction (5%) in test weight affecting density and packing efficiency about equally. Cultivars differed in test weight loss with Neepawa showing the largest reduction of 2.9 and 4.2 kg hL−1 in successive years. Cultivars also differed in susceptibility to bleaching, the primary cause of grade loss. The 1000-kernel weights decreased significantly (1.4%) in only 1 yr. Grain hardness decreased approximately 8% with delayed harvest at similar rates for all cultivars. The hard-grained Glenlea and RL4137 were the most resistant to test weight loss and bleaching, indicating that selection for improvement might be possible.Key words: Harvest delay, weathering, wheat, test weight, seed size, grain hardness

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