Identification of genome donors to the wild species of finger millet, Eleusine africana by genomic in situ hybridization

Abstract

Eleusine africana, which is an important species of the genus Eleusine, grows as an annual wild grass mainly in Africa and in some parts of India. It is an allotetraploid species with the chromosome number of 2n = 4χ = 36 which is considered to be the progenitor of the cultivated species E. coracana. Genomic in situ hybridization (GISH) enabled to identify E. indica and E. floccifolia as 'A' and 'B' genome donors to E. africana, which are also reported to be genome donors to E. coracana. It was observed that at the genomic level the four diploid species with the chromosome number 2n = 18 were closely related to the polyploid species E. africana. The genomic DNA of E. indica, E. floccifolia and E. tristachya hybridized with 15-18 chromosomes and the genomic DNA of E. intermedia labeled about 24-31 chromosomes of E. africana. The same pattern of genomic in situ hybridization of the genomic DNA of these four species with the chromosomes of E. coracana has also been reported. The similar hybridization pattern of the genomic DNA of E. indica, E. floccifolia, E. tristachya and E. intermedia on the chromosomes of the two polyploid species supports the assumption that E. africana is the progenitor of the cultivated species E. coracana.