Estimation of inter-genotypic competitive ability of the parental races (Drosophila nasuta nasuta and D. n. albomicana) and of the newly evolved Cytoraces (I and II)

Interracial hybridization between D. n. nasuta (2 n = 8) and D. n.albomicana (2 n = 6) resulted in the formation of two new karyotypic strains denoted Cytorace I and Cytorace II. The karyotypes of each of these Cytoraces include chromosomal elements from both parental races (Ramachandra and Ranganath 1986a). The parental strains and the newly formed Cytoraces I and II were subjected to interspecific competition. The results reveal that all four experimental strains were competitively superior to the D. melanogaster tested strain. The study indicates certain degree of Cytogenetic divergence between parental and newly evolved genomes.