scholarly journals DIFFERENTIAL RESPONSE TO SELECTION ON THE TWO SEXES IN DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 74 (3) ◽  
pp. 533-542
Author(s):  
Domenico Lorenzo Palenzona ◽  
Rita Alicchio
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variability ◽  
Selection Pressure ◽  
Wing Length ◽  
Differential Response ◽  
Complex Interaction ◽  
Gene Pools ◽  
Response To Selection ◽  
Selection For ◽  
Short Wing

ABSTRACT Artificial selection for short wing was performed in two Drosophila melanogaster populations with partially different gene pools: the C populations were derived from a Canton stock while the H lines were derived from a cross between Canton and a b, cn, vg strain. It is shown that in both populations selection on females (CF, HF) was more effective than selection on males (CM, HM). This difference cannot be explained in terms of differences in additive genetic variability between the two sexes because: (1) both sexes contribute to the genetic variability utilized by selection applied to one sex only, and (2) switching selection pressure on females in the M lines does not result in a response comparable to that obtained in the F populations; this rules out almost completely recombination as the responsible agent for the differences between the selection limits reached by M and F selections.—These results, together with several additional observations concerning sexual dimorphism, fitness and the effect of natural selection, suggest that a complex interaction should be involved in the differential response of M and F lines, controlling the wing length phenotype.

Changes in resistance to powdery mildew in a barley composite cross

1990 ◽  
Vol 68 (4) ◽  
pp. 916-919 ◽  
Author(s):  
M. Reinhold ◽  
M. E. Bjarko ◽  
D. C. Sands ◽  
H. E. Bockelman
Keyword(s):  
Hordeum Vulgare ◽  
Powdery Mildew ◽  
Selection Pressure ◽  
Recurrent Selection ◽  
Erysiphe Graminis ◽  
Response To Selection ◽  
Multiple Alleles ◽  
Negative Effect ◽  
Selection For ◽  
Representative Samples

The response of barley composite cross XLII to selection for resistance to powdery mildew was evaluated. Representative samples from eight cycles of recurrent selection were inoculated with two isolates of Erysiphe graminis f.sp. hordei. Frequencies of resistant plants were determined for each cycle. The resistance in composite cross XLII increased with selection. Increased selection pressure in 1986 resulted in a more rapid increase in resistance than in previous years. Multiple alleles occurring in the Ml-a locus did not seem to have a negative effect on the accumulation of resistance in composite cross XLII. Key words: Hordeum vulgare, barley, Erysiphe graminis f.sp. hordei, powdery mildew, response to selection, recurrent selection.

scholarly journals The genetic analysis of the direct and correlated response to selection for chaetae in Drosophila melanogaster

1973 ◽  
Vol 22 (1) ◽  
pp. 1-7
Author(s):  
W. R. Scowcroft
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Genetic Correlation ◽  
Statistical Approach ◽  
Correlated Response ◽  
Minor Importance ◽  
Response To Selection ◽  
Genetic Changes ◽  
Selection For ◽  
Selection Of

SUMMARYThe direct and correlated response to selection of scutellar microchaetae and scutellar bristles has been analysed by determining the contribution of the three major chromosomes, alone and in combination with each other, to the overall response. The results of the analysis confirm a previous finding, based on a formal statistical approach, that response to selection for microchaetae had highly pleiotropic effects on scutellar bristles. In lines selected, each for high and low microchaetae, genetic changes in the 2nd and 3rd chromosomes are pre-eminent and essentially equal. Inter-chromosomal interactions are of relatively minor importance in interpreting the response to selection for microchaetae but assume greater importance with respect to the correlated character. The results are discussed in terms of the genetic correlation between fitness and the character measured.

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