Assessment of Genetic Diversity Among Indian Jujube Varieties Based on Nuclear Ribosomal DNA and RAPD Polymorphism

Abstract

Indian jujube germplasm characterization, evaluation and improvement are fundamentally based on morphophysiological traits. The lack of break through has been due to under utilization of genetic variability for superior quality and high yield potential. We report the extent of genetic diversity and relationships among 22 putative Ziziphus mauritiana varieties using nuclear ribosomal DNA and RAPD polymorphism. A hybrid protocol of DNA isolation was developed to obtain high molecular weight DNA. Ten RAPD primers generated 101 markers and detected intra-specific variation amounting to 85.15 % polymorphism in banding patterns delineating them into four main clusters and variety Tikadi as a distinct out group. Besides, internal transcribed spacer (ITS) length variations, single nucleotide polymorphism and insertions/deletions (INDELS) in nuclear rDNA region delineated test varieties and revealed lineages with GenBank reference sequences of Z. mauritiana. The novel gene sequences exhibiting nucleotide variations have been submitted to NCBI database and assigned accession numbers from JQ627029 to JQ627050. Higher values of Nei’s genetic diversity (h), Shannon information index (i) and genetic distance analysis validate higher genetic diversity among Indian jujube varieties.The genetically distinct varieties of different phylogenetic clades of RAPD and ITS phylogram can be effectively utilized as parents for crop improvement.