Use of Genome-specific Satellite DNA Sequences to Study the Nature and Extent of Genome Differentiation in Evolution of Lathyrus

Abstract

A cloned restriction fragment of a highly repetitive satellite DNA sequence from L. tingitanus was used as a molecular probe to study the nature and extent of genome differentiation in 22 Lathyrus species and 17 natural population of L. sativus. Sequences homologous to the satellite DNA were identified in the genomes of all Lathyrus species and natural population of L. sativus. However, substantial base sequence divergence was found in sequences homologous to the satellite DNA in different species. This was evident in the large variation in restriction fragment lengths. Similarity indices calculated from the restriction fragment length distributions were compared with the known taxonomical relationship between species established from morphological and molecular studies. The degree of genome differentiation was significantly small between population when compared to the greater variation between species.