Maize Genetics Cooperation Newsletter vol 85 2011

 

 

 

Two-point linkage data for wx1- and Wx1- marked translocations in the Maize Genetics Cooperation Stock Center�s collection: Ten years of data collected and compiled by Janet Day Jackson (1958-2010).

 

                  --Jackson, JD

                  --Stinard, PS

                  --Zimmerman, SA

                  --Sachs, MM

 

 

                  This report summarizes the results of linkage tests between translocation breakpoints (T) and wx1 for wx1- (Table 1) and Wx1-marked (Table 2) translocations in the Maize Genetics Cooperation Stock Center�s collection.  Special attention was given to those translocations for which T – wx1 recombination data had not previously been reported.  See Anderson (1938. Genetics 23:307-313), Patterson (1952. MNL 26:8-12), Patterson (1958. MNL 32:54-66), Anderson et al. (1965. MNL 39:106-109), Jackson (2000. MNL 74:70), Jackson et al. (2001. MNL 75:68-71), Jackson et al. (2002. MNL 76:65-67), and Jackson et al. (2002. MNL 76:67-68) for previous reports of T – wx1 recombination data.

 

                  Linkage crosses were set up as indicated in Tables 1 and 2.  Kernels from test cross ears were separated into starchy and waxy classes, planted in our summer crossing nurseries, and the resulting plants were self-pollinated.  Selfed ears were scored for heterozygous (Wx) vs. homozygous (wx) wx1, and for normal (N) vs. semisterile (�) seed set.  Values and standard errors for the percent recombination between wx1 and the translocation breakpoints were calculated according to the method of Coe (1994. pp. 189-197 in The Maize Handbook, Freeling M and Walbot V, eds., Springer-Verlag, New York).

 

                  In theory, linkage values should be the same for a given translocation regardless of genetic background (M14 or W23) or whether the translocation is marked with wx1 or Wx1.  In many instances this is the case; however, there are some exceptions.  In some instances, the genetic background could have an effect (Patterson EB, 1952. Ph.D. Dissertation. California Institute of Technology, Pasadena, CA).  In other instances, it is possible that a planting error resulted in the substitution of one translocation for another during propagation.  Where possible, linkage tests have been conducted with genetic markers on the relevant chromosome arms to at least confirm the chromosomes involved in the translocations.  See Janet Day Jackson et al.�s numerous MNL reports (1998. MNL 72:79-81; 1998. MNL 72:81-82; 1999. MNL 73:86-88; 1999. MNL 73:88-89; 2000. MNL 74:67; 2000. MNL 74:67-69; 2001. MNL 75:67; 2001. MNL 75:68-71; 2002. MNL 76:65-67; 2002. MNL 76:67-68; 2003. MNL 77:79; 2003. MNL 77:80; 2004. MNL 78: 65-66; 2005. MNL. 79:47; 2005. MNL. 79:48; 2006. MNL. 80:29; 2006. MNL. 80:30; 2010. MNL 84: in press) for summaries of these data.

 

Table 1.  Two-point linkage data for wx1-marked translocations in the Stock Center�s collection.  The inbred conversion used in the linkage tests is indicated (M14, W23, or combined M14 and W23 data).

 

Testcross:  wx1 N X [Wx1 N X wx1 T]

 

Translocation

Breakpoints

Parentals

Recombinants

Totals

% recombination

T – wx1

 

 

Wx N

wx �

Wx �

wx N

 

 

 

 

 

 

 

 

 

 

wx1 T1-9c ^W23

9L.22 1S.48

442

448

39

30

959

7.2 +/- 0.8

 

 

 

 

 

 

 

 

wx1 T1-9(5622)

combined data

9L.10 1L.10

331

252

48

36

667

12.6 +/- 1.3

 

 

 

 

 

 

 

 

wx1 T3-9(8562) ^W23

9L.22 3L.65

527

516

23

16

1082

3.6 +/- 0.6

 

 

 

 

 

 

 

 

wx1 T5-9(022-11) ^M14

9L.27 5S.30

111

115

5

5

236

4.2 +/- 1.3

 

 

 

 

 

 

 

 

wx1 T5-9c ^W23

9L.10 5S.07

96

98

5

5

204

4.9 +/- 1.5

 

 

 

 

 

 

 

 

wx1 T5-9d ^M14

9L.10 5L.14

70

73

2

6

151

5.3 +/- 1.8

 

 

 

 

 

 

 

 

wx1 T5-9d ^W23

9L.10 5L.14

104

108

7

8

227

6.6 +/- 1.6

 

 

 

 

 

 

 

 

wx1 T6-9e ^W23

9L.24 6L.18

171

169

25

13

378

10.1 +/- 1.5

 

 

 

 

 

 

 

 

wx1 T8-9d ^M14

9S.16 8L.09

42

42

4

0

88

4.5 +/- 2.2

 

 

 

 

 

 

 

 

wx1 T8-9d ^W23

9S.16 8L.09

209

196

8

4

417

2.9 +/- 0.8

 

 

 

 

 

 

 

 

wx1 T9-10(059-10) ^W23

9S.13 10S.40

166

125

6

5

302

3.6 +/- 1.1

 

 

Table 2.  Two-point linkage data for Wx1-marked translocations in the Stock Center�s collection.  The inbred conversion used in the linkage tests is indicated (M14, W23, or combined M14 and W23 data).

 

Testcross:  wx1 N X [wx1 N X Wx1 T]

 

Translocation

Breakpoints

Parentals

Recombinants

Totals

% recombination

T – wx1

 

 

Wx �

wx N

Wx N

wx �

 

 

 

 

 

 

 

 

 

 

Wx1 T3-9c ^W23

9S.20 3S.15

243

200

8

8

459

3.5 +/- 0.9

 

 

 

 

 

 

 

 

Wx1 T5-9c ^M14

9L.10 5S.07

484

467

10

40

1001

5.0 +/- 0.7

 

 

 

 

 

 

 

 

Wx1 T5-9c ^W23

9L.10 5S.07

348

372

44

49

813

11.4 +/- 1.1

 

 

 

 

 

 

 

 

Wx1 T6-9b ^W23

9S.37 6L.10

475

475

15

13

978

2.9 +/- 0.5

 

 

 

 

 

 

 

 

Wx1 T7-9(4363) ^M14

9.ctr 7.ctr

906

854

18

23

1801

2.3 +/- 0.4

 

 

 

 

 

 

 

 

Wx1 T9-10(8630) ^M14

9S.28 10L.37

388

406

9

19

822

3.4 +/- 0.6

 

 

 

 

 

 

 

 

Wx1 T9-10(8630) ^W23

9S.28 10L.37

232

201

6

3

442

2.0 +/- 0.7

 

 

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