We try to characterize and use the cytoplasmic male sterile variability of maize for our breeding program and are presently producing hybrids with C and El Salvador (ES) cytoplasms.
For 69 lines combined with a male sterile Cor ES tester the sterility reaction is generally similar for both cytoplasms. However, the reactions of hybrids with F487, F534, F568, W705 A appeared dubious.
During the 1981 season, isogenic combinations were compared in two environments, Montpellier (MTP) and St. Martin-de-Hinx (SMH) (LBS = Late Break of Sterility):
In conclusion, the reactions seem unambiguously identical for the two cytoplasms, which could not be differentiated by fertility restoration.
Conversely, 5 lines chosen for a clear restoration reaction with ES and C male sterile tester were studied in F2 and backcrosses with these testers in Montpellier in 1981.
The phenotypes were noted in accordance with Lijingxiong and Duvick (phenotypes 0, 1, 2 classified as "Sterile," phenotypes 3, 4, 5 classified as "Fertile").
All these crosses appear to segregate for one dominant factor of restoration. However, the fit is not very satisfactory for FR64A.
Luo Fuhe, F. Kaan, A. Panouille, A. Boyat
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