Table 1. The results of restoration of segregating populations of a
restoring line and two sterile lines.
|Year||Combination||Total numbers||Restorer numbers||Sterile numbers||Theoretical ratio||Chi-square test|
|1999, Spring||(cms-CMo17 x Fengke1) F2||315||292||17||15:1||0.294|
|(cms-CMo17 x Fengke1) BC1||87||70||17||3:1||1.673|
|(cms-C237 X Fengke1) F2||195||180||15||15:1||0.692|
|(cms-C237 x Fengke1) BC1||118||92||26||3:1||0.544|
|1999, Summer||(cms-CMo17 x Fengke1) F2||324||292||21||15:1||0.113|
|(cms-CMo17 x Fengke1) BC1||148||116||32||3:1||1.01|
|(cms-C237 x Fengke1) F2||114||103||7||15:1||0.002|
|(cms-C237 x Fengke1) BC1||122||80||41||3:1||4.091*|
|2000, Spring||(cms-CMo17 x Fengke1) F2||391||365||26||15:1||0.107|
|(cms-CMo17 x Fengke1) BC1||83||61||22||3:1||0.100|
Note: *, Chi-square test did not suit to theoretical ratio
Equal amounts of DNA from 20 restorer plants and 20 sterile plants, from the F2 progeny of the crosses (cms-CMo17 x Fengke1), were mixed randomly to get the bulked pools. One hundred and sixteen pairs of microsatellite primers were used to screen parents and pools. Primers bnlg1711, umc1225, bnlg1346, umc1072, phi058 on chromosome 5L and the primer bnlg2307 on chromosome 8S produced polymorphic fragments which amplified in one parent or pool and not the other.
The primers, bnlg1711, bnlg1346, phi058, linked tightly with Rf5, and bnlg2307 linked with Rf4, amplified successfully for both parents and 141 individuals selected from F2 progeny (Table 2). Microsatellite DNA products amplified by bnlg1711 and bnlg1346 are shown in Figure 1 and Figure 2.
Table 2. The statistical results of molecular markers and phenotypes
of F2 segregating populations of (cms-CMo17 x Fengke1).
Note: A: Labeled band of Fengke1; B: Labeled band of cms-CMo17; H: Hybrid band; U: Unknown band
Figure 1. Microsatellite DNA products amplified by bnlg1711 in parents and some individuals of F2 progeny.
Figure 2. Microsatellite DNA products amplified by bnlg1346 in parents and some individuals of F2 progeny.
The linkage analysis between Rf5 and microsatellite markers was performed by JOINMAP version 1.4. The linkage distances between bnlg1346-Rf5-bnlg1711 were 1.68 cM and 7.51 cM respectively, and for phi058-Rf5 the distance was 9.87 cM. As the three microsatellite primers tightly linked with Rf5 are in bin 5.07 of chromosome 5, the restorer gene Rf5 is also at bin 5.07 of chromosome 5. The locations of the markers, phi058, bnlg1346, bnlg1711, and Rf5 are displayed in Figure 3.
3. Map location of Rf5/rf5 and the microsatellite markers.
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