Geographical and Racial Distribution of Restorers and Maintainers on Milo and Maldandi Cytoplasm from Minicore Collection of Sorghum

To determine the distribution and geographic specificity of sterility maintainers and restorers in Sorghum bicolor (L.), 168 diverse sorghum germplasm accessions representing variation from 26 countries were crossed with a male-sterile lines milo and maldandi cytoplasm. The F1 hybrids were classified as male-fertile or male-sterile based on the seed set on bagged ear heads. Among these, 43 (25.59 %) were classified as strong restorers with > 90 % seedset and 41 (24.40 %) as maintainers with zero seedset in the postrainy season. Maintainers on maldandi cytoplasm represented 16 out of 26 countries but were concentrated comparatively high in India and for restorers distributed in 15 countries. Maintainer and restorers for milo cytoplasm were distributed across globe. Most of the identified restorers and maintainers of milo and maldandi cytoplasm belongs to race of caudatum and its hybrid races like caudatum-bicolor, durra-caudatum, guinea-caudatum etc. These maintainer lines differ from one another in several morphological and agronomic characters such as flowering, plant height, panicle length and grain size. They may prove to be useful sources of material for generating new male-sterile lines. The restorers can be used to produce commercial hybrids.