A Review on Molecular Characterization of Citrus Species

Efficient identification and characterization of the accessions is highly required for the conservation and sustainable use of plant genetic resources. Since the entire plant kingdom cannot be covered under sequencing projects, molecular markers and their correlation to phenotypes provide us with requisite landmarks for classification and genetic variation. Various molecular techniques such as Random Amplified Polymorphic DNA (RAPD), Amplified Fragment Length Polymorphism (AFLP), Sequence-Related Amplified Polymorphism (SRAP), Inter Simple Sequence Repeats (ISSR), Simple Sequence Repeats (SSR) and Single Nucleotide Polymorphisms (SNPs) have recently been used for fruit plant characterization. The construction of genetic maps using RFLP was the first reported molecular marker technique in the detection of DNA polymorphism (Botstein et al., 1980). The projects of genome sequencing for several fruit crops such as citrus, apple, peach and strawberry has good results in molecular characterization. Attempts were made to classify citrus using molecular markers like RFLP and RAPD (Federici et al., 1998; Baig et al., 2009). AFLP markers have the advantages over other molecular markers like, SSR, RFLP and RAPD.