Two sets of interspecific hybrids E. coracana x E. africana and E. coracana x E. indica were produced. The hybrids were intermediate between the parent species for most of the matrical characters observed. The dominance-recessive relationships of various qualitative characters were studied in the hybrids. Meiotic behaviour was normal in the parent species. Regular 18 bivalents were observed in E. coracana, E. africana and invariably 9 bivalents were noticed in E. indica. In an E. coracana x E. africanahybrid mean chromosome pairing of 0.004 I + 17.71 11 + 0.06 III + 0.08 IV per cell was found. About 87% of the cells showed regular 18 bivalent formation. Preponderance of bivalent formation in the hybrid strongly suggests that the genomes of E. coracana and E. africana are basically similar and E. coracana might have originated as a result of selection and further cultivation of a large grain mutant from E. africana. The genomic notation of AABB has been proposed for these two species. From meiotic analysis it is obvious that E. africana is an allotetraploid and must have originated as a result of hybridization between two diploid taxa followed by chromosome doubling. In triploid E. coracanax E. indica hybrid 99.5 % of the cells contained 27 univalents and 0.5 % of the cells showed a single bivalent and 25 univalents. This pairing behaviour indicates that E. indica may not be A or B genome donor to this millet.

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SUMMARY -Eleusine is a small genus currently containing 9 species. From cytological analyses of all nine species it is shown that Eleusine contains three basic chromosome numbers 8, 9 and 10. Among the five diploid taxa the basic number is 8 in E. multiflora (2n = 2x = 16) and 9 in E. floccifolia, E. tristachya, E. indica (all 2n = 2x = 18) and 10 in E. ;aegeri (2n = 2x = 20). The 4 tetraploid species E. africana, E. coracana, E. reniformis (all 2n = 4x = 36) show a base number of 9, while E. compressa (2n = 4x = 40) has a base number of 10. From various lines of evidences it is suggested that 9 is the original base chromosome number in the genus. It appears that aneuploid reduction has played a role in the origin of the number 8 found in E. multiflora, while the two taxa E. ;aegeri (2n = 2x = 20) and E. compressa (2n = 4x = 40) with a x = 10 number appears to have originated through gain to the basic set of nine. In Eleusine the chromosomes are all small to medium in size. The presumed primitive species, E. floccifolia is characterised by a symmetrical karyotype, while the morphologically more advanced taxa show varying degrees of asymmetry in their chromosome complements. Meiotic analysis of the tetraploid taxa shows regular bivalent formation in E. africana, E. coracana, E. reniformis and E. compressa suggesting their allotetraploid origin. There are grounds for arguing that E. coracana originated through selection and further cultivation of a large grain mutant from E. africana, while E. reniformis appears to be a simple varietal derivative of E. coracana.

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