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Evidence for Homoeologous Linkage Groups in the Soybean
Author(s) -
Lohnes D. G.,
Specht J. E.,
Cregan P. B.
Publication year - 1997
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/cropsci1997.0011183x003700010045x
Subject(s) - biology , locus (genetics) , genetics , genotype , epistasis , genotyping , allele , population , genetic linkage , gene , demography , sociology
Substantial progress towards the integration of the soybean [ Glycine max (L.) Merr.] classical and molecular marker linkage maps recently was achieved by using a 60‐plant F2 population derived from a mating of isolines of the cultivars Clark and Harosoy. However, epistasis limited the completeness of F2 genotyping at two independently segregating loci, D1 and D2 , which produced yellow (Y) and green (G) cotyledons in a duplicate recessive fashion (i.e., only the d1d1d2d2 F2 genotype was green). F2 genotypic assignments were obvious for two of the four F2.3 phenotypes (15Y:1G from 1d1D2d2 and all G from d1d1d2d2 ), but were equivocal for the other two (all Y from D1D1D2D2 , D1D1D2D2 , D1d1D2D2 , D1D1d2d2 , or d1d1D2D2 ; 3Y:1G from D1d1d2d2 or d1d1D2d2 ). Here, we propose an inferential means of near complete F2 genotyping, by using F2.3 data collected on locus G , which produces G ( GG and Gg ) and Y ( gg ) seed coats. Locus G is tightly linked (4.2%) to the D1 locus. Given the repulsion‐phase parental gametes of Gd1 and gD1 . we inferred, with a low probability of (recombinational) error, that the GG , Gg , or gg F2 genotypes must be d1d1 , D1d1 , or D1D1 , respectively. Genetically, a F2 plant with all Y or 3Y:1G F2.3 progeny and an inferred GGd1d1 genotype must also be D2D2 or D2d2 , respectively, and an inferred GgD1d1 genotype must also be D2D2 or d2d2 , respectively. The alleles at D2 could not be inferred from the ggD1D1 genotype. The updated 60‐plant marker data, when subjected to a Mapmaker linkage analysis, revealed that D1 mapped (as expected) to linkage group (LG) 1 and D2 mapped to LG10 of the Clark ✕ Harosoy map. Duplicate genes and homoeologous linkage groups support the hypothesis that the diploid soybean is derived from a tetraploid.