S. Rajan

Genetic diversity and population structure analysis of mango (Mangiferaindica) cultivars assessed by microsatellite markers

Key messageSSR marker characterization of Indian mango cultivars revealed two distinct groups of populations with geographical affiliation. Six SSR loci with low PI have been identified as universal markers for mango characterization.AbstractIn this study, genetic diversity and population structure of mango cultivars were assessed by employing fourteen simple sequence repeat markers, with high polymorphic information content. A set of 387 mango accessions from different regions of India was used. Model-based structure analysis revealed the presence of two subpopulations comprising the cultivars from ‘South-West’ region and ‘North-East’ region. A similar clustering pattern was observed in the dendrogram analysis, with two major groups identified that were further sub-grouped based on their genetic relatedness. Analysis of molecular variance showed a significant variance component among and within mango sub-populations derived from the structure analysis. The proportion of genetic differentiation among individuals within the two populations was found to be significant with a FST value of 0.248. The extent of genetic diversity was found to be higher in case of ‘South and West’ population than ‘North and East’ population. Six SSR loci with low probability of identity values have been chosen as universal markers for mango characterization. Our results highlight genetic diversity encompassed by mango cultivars and genetic distinctness of ‘South-West’ and ‘North-East’ region cultivars.

Phytochemical and therapeutic potentials of Morinda tinctoria Roxb. (Indian mulberry)

SUMMARY Morinda tinctoria Roxb. (Family: Rubiaceae) is commonly known as Indian mulberry or Aal inIndia. This plant is very well known for its therapeutic benefit in Indian systems of medicineincluding Ayurveda and Siddha and in other forms of traditional Medicine worldwide for thetreatment of several ailments. Almost all parts of this plant have been explored for its medicinaluses. Several reports on the phytochemical and therapeutic benefits of this plant have beenreported. In this article an attempt has been made to review the traditional uses, phytochemicalprofiles and therapeutic potentials of Indian mulberry.Key words: Morinda tinctoria ; Therapeutic potential; Phytoconstituents; Ayurveda; Siddha; Indianmulberry INTRODUCTION Botanical drugs and dietary supplements may bederived from a broader variety of plants that arenormally present in the human diet. Botanicals orphytopharmaceuticals are a perfect fit for prophylacticuse in order to prevent diseases and also for ournormal wellbeing. The screening and evaluation ofmedicinal plants mostly depends on propercultivation and collection of the plant materialsfollowed by their extraction and deriving thephytochemical entities to access the optimizedbioactive compound production and use in therapy.This is very much required for multi-componentdrugs and their standardized extracts for assuringthe quality and batch to batch consistency(Mukherjee, 2002). The Indian subcontinent, withthe history of one of the oldest civilization,harbours many traditional health care systems.Their development was supported by the diversebiodiversity in flora and fauna due to variations ingeographical landscaping (Mukherjee and Wahile,2006). Therefore the potential plants need to beexplored for new drug development. Reviews ofseveral medicinal plants including oriental medicineMangifera indica (Rai et al., 2007), therapeutic potentialsand untoward effects of Piper betle (Rai et al., 2005)has been reported from our laboratory. Beside this

Molecular analysis of anthocyanin biosynthesis pathway genes and their differential expression in mango peel

Mango fruit is cherished by masses for its taste and nutrition, contributed by color, flavor, and aroma. Among these, peel color is an important trait contributing to fruit quality and market value. We attempted to elucidate the role of key genes of the anthocyanin biosynthesis pathway related to fruit peel color from the leaf transcriptome of mango cultivar Amrapali. A total of 108 mined transcript sequences were assigned to the phenylpropanoid-flavonoid pathway from which 15 contigs representing anthocyanin biosynthesis genes were annotated. Alternate splice variants were identified by mapping against genes of Citrus clementina and Vitis vinifera (closest relatives) and protein subcellular localization was determined. Phylogenetic analysis of these pathway genes clustered them into distinct groups aligning with homologous genes of Magnifera indica, C. clementina, and V. vinifera. Expression profiling revealed higher relative fold expressions in mature fruit peel of red-colored varieties (Arunika, Ambika, and Tommy Atkins) in comparison with the green-peeled Amrapali. MiCHS, MiCHI, and MiF3H alternate splice variants revealed differential gene expression. Functionally divergent variants indicate availability of an allelic pool programmed to play critical roles in peel color. This study provides insight into the molecular genetic basis of peel color and offers scope for development of biomarkers in varietal improvement programs.

Intra- Cultivar Variability Endorsed by SSR Markers in Mango

Published by Oriental Scientific Publishing Company

MiSNPDb : a web-based genomic resources of tropical ecology fruit mango ( Mangifera indica L.) for phylogeography and varietal differentiation

Mango is one of the most important fruits of tropical ecological region of the world, well known for its nutritive value, aroma and taste. Its world production is >45MT worth >200 billion US dollars. Genomic resources are required for improvement in productivity and management of mango germplasm. There is no web-based genomic resources available for mango. Hence rapid and cost-effective high throughput putative marker discovery is required to develop such resources. RAD-based marker discovery can cater this urgent need till whole genome sequence of mango becomes available. Using a panel of 84 mango varieties, a total of 28.6 Gb data was generated by ddRAD-Seq approach on Illumina HiSeq 2000 platform. A total of 1.25 million SNPs were discovered. Phylogenetic tree using 749 common SNPs across these varieties revealed three major lineages which was compared with geographical locations. A web genomic resources MiSNPDb, available at http://webtom.cabgrid.res.in/mangosnps/ is based on 3-tier architecture, developed using PHP, MySQL and Javascript. This web genomic resources can be of immense use in the development of high density linkage map, QTL discovery, varietal differentiation, traceability, genome finishing and SNP chip development for future GWAS in genomic selection program. We report here world’s first web-based genomic resources for genetic improvement and germplasm management of mango.