CHARACTERIZATION OF THE A(4) CYTOPLASMIC MALE-STERILE LINES OF SORGHUM USING RFLP OF MTDNA

Three sorghum cytoplasmic male sterile lines CSV4 A(V), CSV4 A(G(1)) a nd CSV4 A(M), grouped as A(4), were compared with a mile (A(1)) and tw o other non-mile (A(2) and A(3)) cytoplasms for their RFLP patterns of mitochondrial DNA (mtDNA). A 9.7 kb clone from pearl millet mtDNA dis criminated each of the three A(4) entries whereas other maize and pear l millet mtDNA clones used could not distinguish this group completely . The molecular differences within the A(4) cytoplasmic group offer so me explanation for the inconsistency in the fertility restoration beha viour of these A(4) lines obtained with a definite set of testers in t he field.