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Efficiencies of F 2 and Backcross Generations for Bulked Segregant Analysis Using Dominant Markers
Author(s) -
Mackay I.J.,
Caligari P.D.S.
Publication year - 2000
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2000.403626x
Subject(s) - bulked segregant analysis , quantitative trait locus , backcrossing , biology , genetics , epistasis , genetic marker , trait , recombination , gene mapping , gene , computer science , programming language , chromosome
Bulked segregant analysis (BSA) is being used increasingly as a screen for quantitative trait loci (QTL), which have been suggested to be more easily detected in backcross (Bc) populations than in the F 2 However, for dominant markers the number of loci segregating in the F 2 will be double that in the Bc, and the probability of false‐positive results differs between F 2 and Bc generations. This study was conducted to re‐examine the relative value of Bc and F 2 populations for use in BSA by using theoretical estimates of the genotypic composition of the selected bulks. It is shown that doubling the number of marker loci segregating in the F 2 roughly halves the expected distance from the QTL to the nearest marker, while the bulk size in the F 2 can be reduced to nearly one‐half that of the Bc and still give the same probability of a false positive. The results show that for the same recombination frequency, the Bc is slightly superior to the F 2 in its ability to detect QTL. However, if the likely distance of the nearest marker to the QTL is taken into account, the F 2 is the more favorable generation. Overall, for dominant marker systems, the F 2 is therefore the best generation in which to conduct BSA.