S.K. Singh

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.

Effect of polyembryonic rootstocks on leaf mineral composition of five cultivars under Inceptisol

The leaf macro- and micro-nutrient concentrations of five mango scion cultivars grown on three polyembryonic rootstock genotypes were studied during 2012–13 and 2013–14. Among the cultivars, Pusa Arunima appeared be the good accumulator for most of the nutrient elements except leaf N. Though, Amrapali seems to be the good accumulator of N and Mg but poorest accumulator of P, K, and Zn. Whereas, Mallika was good accumulator of N and Mg but poorest accumulator of Mn, Zn and Cu. Among rootstocks, Kurakkan was found potential for higher accumulation of leaf N, Ca, Mg and Zn concentrations in scion cultivars. Among different rootstock-scion combinations, leaf nitrogen (1.25%) and K (0.54%) in Pusa Arunima was observed higher on K-5 rootstock, while higher leaf N in Amrapali (1.36%) and Mallika (1.37%) were estimated on Kurakkan rootstock but Pusa Surya tree on Olour had higher leaf N (1.26%). In most of the cultivars, leaf K was higher on K-5 rootstock. Besides, higher leaf Ca in Pusa Arunima, Mallika and Dushehari were observed on K-5 rootstock, while in Amrapali and Pusa Surya, trees on Kurakkan had higher leaf Ca concentration. Similarly, leaf Mg concentration was also found higher on K-5 rootstock in Pusa Arunima, Amrapali, Mallika and Dushehari. The Pusa Arunima and Pusa Surya on Kurakkan proved its ability for leaf Fe and Mn concentrations, whereas, K-5 rootstock found superior over other rootstocks for the highest accumulations of Fe and Mn in Dushehari and Mallika. Both Kurakkan and Olour were equally effective for higher accumulation of Zn in Amrapali. Based on present study, it can also be inferred that metabolism of Kurakkan and/or K-5 is better adapted for N, K, Ca, Mn, Fe and Zn accumulation for most of the mango cultivars tested.