Urbana, Illinois
Maize Genetics Cooperation • Stock Center
Three-point linkage data for du1, inr1 and g1 on 10L --Philip Stinard In last year’s MNL (Stinard, P, MNL 75:71, 2001), we reported two-point linkage data for du1 and inr1 on the long arm of chromosome 10. In that experiment, a three-point linkage test involving the 10L markers inr1, du1, and g1 had been set up as indicated in Table 1 (R1-S is an r1 allele that is susceptible to inhibition by Inr1; wx1 facilitates the scoring of du1). However, scoring of the progeny for g1 had not been done by the MNL deadline, so only two-point du1 inr1 data were presented. This past winter and summer, Du1 inr1 and du1 Inr1 crossover kernels from these crosses were planted and the resulting plants scored for g1 in order to provide partial three-point linkage data. Crosses were made in order to confirm the du1 and inr1 scoring as well. Complete scoring of the parental classes for g1 was not done because of the large populations involved, and because complete scoring was not necessary for determining the gene order since the linkage relation between du1 and g1 is already well-characterized (these two loci are 19 centimorgans apart). The partial three-point linkage data are presented in Table 1. These data confirm that inr1 and du1 are very tightly linked, with an approximately 0.14 centimorgan distance between them. These data furthermore determine the global order of the three loci on chromosome 10 as du1 inr1 g1.

Table 1. Partial three-point linkage data for du1, inr1 and g1.

Testcross: (Du1 Inr1 G1 R1-S wx1 X du1 inr1 g1 R1-S wx1) X du1 inr1 g1 R1-S wx1.
Reg. Phenotype No. Totals
0; 2 Du Inr; G or g 4357  
  du inr; G or g 4411 8768
1 Du inr g 6  
  du Inr G 4 10
1 + 2 Du inr G 1  
  du Inr g 1 2

% recombination du1--inr1 = 0.14 +/- 0.04

Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.

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