CYTOPLASMIC MALE-STERILITY IN SORGHUM - ORGANIZATION AND EXPRESSION OF MITOCHONDRIAL GENES IN INDIAN CMS CYTOPLASMS

Cytoplasmic male sterility in sorghum has been reported in a number of varieties originating in different geographical regions (India, Afric a and America). We have attempted to characterize three male sterile c ytoplasms of Indian origin designated as Maldandi, Guntur and Vizianag aram by studying restriction fragment length polymorphisms (RFLPs) and expression patterns of 14 mitochondrial genes. Our results indicate t hat the cytoplasms, classified tentatively as Indian A, types, are dis tinct from the American A, and A, types. Although they are identical t o each other with respect to the location of 10 of the mitochondrial g enes selected, they can be distinguished from each other on the basis of RFLPs in atp6, atp9 and rrn18. Further the three cytoplasms differ from their maintainers in the location of nad3, rps12 and atpA. Differ ences are also observed in the pattern of expression of atpA between a ll the sterile lines and their respective maintainers.