Morphological characterization and Simple Sequence Repeats (SSRs) based DNA fingerprinting of selected mango (Mangifera indica L.) genotypes in Bangladesh

Abstract

Nineteen genotypes of mango including nine released varieties viz. BARI Aam-1, BARI Aam-2 (Laxmanbhog), BARI Aam-3, BARI Aam- 4 (Hybrid), BARI Aam-5, BARI Aam-6, BARI Aam-7, BARI Aam-8, BARI Aam-9; one parental line viz. M- 3896 and nine Geographical Indication Crops (GIs) viz. Haribhanga, Surjapuri, Fazli, Gourmoti, Ashwina, Khirsapat, Gopalbhog, Langra and Ranipasand were characterized with a view to identifying the degree of morphological and molecular variation of mango within genotypes with their historical background their historical background, and to establish a permanent database for documentation of mango in Bangladesh. Wide variations were observed among GI crops and released varieties included in this study for plant, leaf, flower and fruit characters. Among 19 mango genotypes, eight were distinct by two traits and 11 by only single character. Molecular characterization was carried out with SSR markers. Using 21 primers across 19 genotypes a total of 80 alleles with an average number of 3.81 alleles per locus were found of which MIAC-6 and MIAC-11 showed the highest number of alleles (6) (size ranging from 244 to 312 and 133 to 167 bp, respectively). However, the lowest number of allele (2) with size ranging 237 to 366 and 118 to 125 bp was observed in the locus MiSHRS-39 and MIAC-11, respectively. The polymorphic information content (PIC values) ranged from 0.349 to 0.781, with a mean value of 0.602 for all loci. Of the 21 SSR primers, 13 were highly informative (PIC value ≥0.6). The distinct level of heterozygosity indicated higher level of diversity among the genotypes. Band patterns corresponding to individual genotype have been identified to discriminate the genotype. The genotypes presented genetic distances between 0.260 and 1.557. The dendrogram generated from UPGMA cluster analysis broadly placed 19 mango genotypes into two major groups, “A” and “B” in which only one poly-embryonic genotype namely BARI Aam-8 congregated in a distinct group “B” and other 18 mono-embryonic genotypes clustered in group “A”. The dendrogram revealed that Gourmoti and Ashwina were the most similar hybrids with 21% similarity. Contrary to this, hybrids BARI Aam-5 and BARI Aam-8 were the most divergent with a diversity value of 1.56. Key words: Geographical Indication Crops (GIs), historical background, morphology, identity.