Extremely diverse structural organization in the complete mitochondrial genome of seedless Phoenix dactylifera L

Abstract

Mitochondrial genome of seedless (mutant) variety of Phoenix dactylifera is analyzed to understand the probable reason for seedless condition. The size of the genome is 585,493\xa0bp long which is 129,508\xa0bp shorter compared to the normal genome and demonstrate significantly higher rate of nucleotide loss. The loss is evident in coding and non-coding regions. Missing of all rRNA genes and other three genes, i.e., rps14, rps13, rps19 is observed. Total 2726 SNPs are recorded, showed 80.9% identity with the normal genome. The ratio of nonsynonymous (dN) synonymous (dS) substitution (dN/dS) is more than one for nad7, nad1, ccMb, ccmC, cob, matR, matB suggest adaptive selection while less than one for cox2 suggest strong selective pressure on this gene and reduction in size may be start of its transfer to nucleus. Such variations may play an important role in seedless condition is discussed.