Appraisal of biochemical and genetic diversity of mango cultivars using molecular markers

Mango ( Mangifera indica L.) is one of the oldest fruit crops and is broadly cultivated worldwide. To determine the level of genetic diversity, a total of 13 mango genotypes have been collected from different farms of Fayoum oasis in Egypt and were analyzed using molecular (DNA) and biochemical (SDS-PAGE) markers along with the quantification of soluble carbohydrates, chlorophyll and carotenoids. These profiles were evaluated as characters to identify the taxonomic relationships of these genotypes. A total of 433 protein bands (ranged from 8 to 180 KDa) from all genotypes, were detected in SDS-PAGE. A total of 306 RAPD fragments were produced by 19 primers and among them 123 (40.2%) were polymorphic. The similarities between different taxa were estimated by Jaccard’s similarity index and clustered in neighbour joining clustering tree. Among the 13 tested mango samples, the total carbohydrate contents ranged between 31.9 and 40.8 µg/100 mg fresh weights, which represents Taymour cultivar and accession No. 7, respectively. Of the 13 mango cultivars and accessions studied, the highest chlorophyll content (386.9 µg/g) was found in accession No. 10; whereas, the lowest value was observed with accession No. 12 (202.5 µg/g). The amounts of carotenoids were wide-ranging and reached a maximum value of 106.2 µg/g with accession No. 9, however, accession No. 8 recorded the lowest concentration (19.9 µg/g). In conclusion, RAPD-PCR and SDS-PAGE were proved to be an efficient tool in assessing the genetic diversity of mango genotypes. It will also provide an important input to breeders for mango improvement program. Keywords: Mango, genetic diversity, chlorophyll, SDS-PAGE, RAPD. African Journal of Biotechnology Vol 13(28) 2796-2806