EXPERIMENTAL INVESTIGATION OF ERRORS OF HERITABILITY ESTIMATES IN INDEX SELECTION

1979 ◽  
Vol 21 (3) ◽  
pp. 303-308 ◽  
Author(s):  
C. Y. Lin ◽  
I. Pevzner ◽  
G. W. Friars
Keyword(s):  
Experimental Investigation ◽  
Parameter Estimation ◽  
Tribolium Castaneum ◽  
Genetic Change ◽  
Pupal Weight ◽  
Index Selection ◽  
Selection Efficiency ◽  
Larval Weight ◽  
Estimation Errors ◽  
Selection For

Three generations of index selection for the combined genetic gain in 13-day larval and 21-day pupal weight were carried out in each of three replicates in Tribolium castaneum. Five indexes were constructed using differing levels of heritability for larval weight (0.9, 0.7, 0.5, 0.3 and 0.1). The effect of parameter estimation errors, involving larval weight, on the efficiency of index selection was thus evaluated experimentally. The results from this experiment confirmed the theoretical expectations that errors of parameter estimation would affect the efficiency of index selection. The present study further showed that the overestimation of the parameters would affect the selection efficiency more than the underestimation. The combined gain was found to be realized mainly through genetic change in pupal weight, a trait with lower heritability.

COMPONENTS OF GROWTH IN GENETICALLY DIVERSE POPULATIONS OF TRIBOLIUM CASTANEUM

1969 ◽  
Vol 11 (4) ◽  
pp. 896-907 ◽  
Author(s):  
DuWayne C. Englert ◽  
A. E. Bell
Keyword(s):  
Tribolium Castaneum ◽  
Adult Emergence ◽  
Pupal Weight ◽  
Diverse Populations ◽  
Correlated Responses ◽  
Larval Weight ◽  
Developmental Patterns ◽  
Adult Weight ◽  
Total Growth ◽  
Selection For

The growth and developmental patterns of 19 genetically diverse populations of Tribolium castaneum were examined. Measurements were obtained on three primary traits (13-day larval weight, pupation time and pupal weight) and three secondary traits (number of larval molts, adult emergence time and adult weight). The populations were chosen on the basis of their previous selection histories. Selection for different primary traits produced profound effects upon the total growth and development complex.Genetic and environmental relationships between primary traits were estimated within each population, and a consistent asymmetry of correlated responses was observed to be determined by the direction of selection.Possible effects upon the disruption of an intricate balance of the three metamorphosis hormones (activation, molting and juvenile) through selection were postulated.

TWO-WAY SELECTION ON PUPAL WEIGHT WITH DIFFERENT DEGREES OF INBREEDING IN TRIBOLIUM CASTANEUM

1974 ◽  
Vol 16 (4) ◽  
pp. 765-775 ◽  
Author(s):  
P. Y. Jui ◽  
G. W. Friars
Keyword(s):  
Tribolium Castaneum ◽  
Linear Response ◽  
Significant Interaction ◽  
Pupal Weight ◽  
Base Population ◽  
Significant Progress ◽  
Selected Lines ◽  
Selection Limit ◽  
Selection For ◽  
Seven Generations

Responses to selection for high and low pupal weight in Tribolium castaneum under four different inbreeding systems and two different relative humidities (40 and 70%) were observed for seven generations. By the seventh generation, the coefficients of inbreeding ranged from 0.79 in the full sib lines to 0.12 in the control lines.Heritability of pupal weight estimated by mid-parent offspring regression from the base population was around 0.30 which is lower than the estimates obtained by Bell (1969). However, realized heritabilities were around 0.50. Significant progress was observed for both upward and downward selection. A linear response in pupal weight was observed for most of the selected lines, suggesting that the selection limit had not been reached.Inbreeding caused a reduction of approximately two offspring per 10% increment in the inbreeding coefficient.Asymmetric responses were noted in conjunction with the significant interaction of the degree of inbreeding and the direction of selection.

The effects of alternated cycles of full-sib and random mating on selection for pupa weight in Tribolium castaneum

1985 ◽  
Vol 27 (2) ◽  
pp. 251-254 ◽  
Author(s):  
Nicole Dion ◽  
Francis Minvielle
Keyword(s):  
Mating System ◽  
Tribolium Castaneum ◽  
Random Mating ◽  
Selection Response ◽  
Inbred Lines ◽  
Pupal Weight ◽  
Realized Heritability ◽  
Differential Selection ◽  
Selection For

Individual responses to selection for high pupal weight in Tribolium castaneum under two types of mating, cyclic full-sib random-mating system and random mating, were observed for 15 generations. No significant differences have been observed between the two types of mating for the selection response, differential selection, realized heritability, and the number of larvae per generation. Realized heritability of the pupal weight was 0.33 ± 0.02 and 0.42 ± 0.02 for the inbred lines and for the random-mated lines, respectively.Key words: inbreeding, pupa weight, Tribolium.

Effects of parental age and sampling method on response to index selection in Tribolium castaneum

1983 ◽  
Vol 25 (1) ◽  
pp. 47-52 ◽  
Author(s):  
D. L. Patterson ◽  
G. W. Friars ◽  
I. McMillan
Keyword(s):  
Variance Components ◽  
Sampling Method ◽  
Sampling Methods ◽  
Genetic Correlations ◽  
Pupal Weight ◽  
Parental Age ◽  
Larval Weight ◽  
Selection Experiments ◽  
Two Generations ◽  
Selection For

Two generations of individual selection on the basis of an index incorporating the 13th day larval weight and pupal weight were carried out using Triboliumcastaneum. The experimental design consisted of two sampling methods by three parental ages and was repeated three times concurrently (three sets). Eight offspring for each of 10 families per set were measured. Heritabilities and phenotypic and genetic correlations for larval and pupal weights were estimated using variance components. Age of parents had an effect on response to selection for total merit. Offspring of older parent stocks had heavier larval weight. Sampling parents from one subpopulation versus sampling from a group of subpopulations had no consistent effect on total merit. Although the overall effect of set was not significant, interactions of set with sampling method and parental age were significant, indicating that control of these factors might reduce among replicate variation commonly seen in selection experiments.

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