Microsatellite-Based DNA Fingerprinting of Guava (Psidium guajava) Genotypes

Molecular fingerprinting exploits the variation between individuals at the genome level. It is generally performed for clear identification of various accessions, verifying ambiguous nomenclature, i.e., if similar cultivars are known by different names and different cultivars are called by similar names; to address Intellectual Property Rights related issues in the case of developed hybrids. The objective of the present study was to genotype and deoxyribonucleic acid (DNA) fingerprint 79 guava (Psidium guajava) accessions. Statistical analysis was performed by CERVUS 3.0 software. DNA fingerprint of the guava genotypes was developed by using 13 microsatellite loci that showed high polymorphic information content (PIC), allelic number per loci, and heterozygosity values. A total of 86 different alleles were amplified; number of alleles per locus ranged from five to nine, with a mean of 6.5. Allelic sizes ranged from 86 to 256 bp and the observed heterozygosity values ranged from 0.00 to 0.364. The expected heterozygosity varied from 0.689 to 0.821. The PIC varied from 0.630 to 0.789. Probability of identity varied from 0.05 to 0.12. The DNA barcode developed is very discriminative. So, it can be used for efficient and unambiguous identification of guava accessions, thereby increasing the accuracy in maintenance of genetic resources. Apart from the DNA fingerprint, interpretation of the results clearly indicated that each accession had a unique allelic combination at the 13 nuclear microsatellite loci, indirectly reflecting the fact that none of accessions were similar.