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Das, R. R.

Publications and source records attributed to Das, R. R..

5 recordsLinked to original sources
bioRxiv2024

Whole genome assembly of the Little Millet (Panicum sumatrense) genome: A climate resilient crop species

Little millet (Panicum sumatrense) belongs to one of the largest genera, Panicum comprising of 500 species that are distributed especially in tropical and sub-tropical Asia as well as Africa. This is a climate resilient crop that has the ability to adapt to adverse growing conditions, especially drought. Added to this is the better nutritional profile of little millet, which has higher iron and fibre contents as compared with rice. These characteristics make it an important crop species that would be pivotal for ensuring food security. Generating genomic resources for the species is significant and will have implications in crop improvement. Therefore, in the present study we report the de novo whole genome sequence of P. sumatrense. Long read sequencing and Hi-C based scaffolding resulted in a total of 279 scaffolds with N50 of 7.8Mb. The genome was annotated to predict protein coding genes and orthologous groups were analysed after comparison with various plant genomes. This high-quality genome assembly can be a valuable resource as future reference for genomic studies in this crop and related crop species.

genomics↗
bioRxiv2022

DeepVariant calling provides insights into race diversity and its implication for sorghum breeding

Due to evolutionary divergence, sorghum race populations exhibit vast genetic and morphological variations. A k-mer-based sorghum race sequence comparison identified the conserved k-mers of all sorghum race accessions and the race-specific genetic signatures identified the gene variability in 10,321 genes (PAVs). To understand the sorghum race structure, diversity and domestication, deep learning-based variant calling approach was employed in a set of genotypic data derived from a diverse panel of 272 sorghum accessions. The data resulted in 1.7 million high-quality genome-wide SNPs and identified selective signature (both positive and negative) regions through a genome-wide scan with different (iHS and XP-EHH) statistical methods. We discovered 2,370 genes associated with selection signatures including 179 selective sweep regions distributed over 10 chromosomes. Localization of these regions undergoing selective pressure with previously reported QTLs and genes revealed that the signatures of selection could be related to the domestication of important agronomic traits such as biomass and plant height. The developed k-mer signatures will be useful in the future to identify the sorghum race and SNP markers assist in plant breeding programs.

plant biology↗
bioRxiv2021

Sorghum pan-genome explores the functional utility to accelerate the genetic gain

Sorghum (Sorghum bicolor L.) is one of the most important food crops in the arid and rainfed production ecologies. It is a part of resilient farming and is projected as a smart crop to overcome the food and nutritional challenges in the developing world. The development and characterisation of the sorghum pan-genome will provide insight into genome diversity and functionality, supporting sorghum improvement. We built a sorghum pan-genome using reference genomes as well as 354 genetically diverse sorghum accessions belonging to different races. We explored the structural and functional characteristics of the pan-genome and explain its utility in supporting genetic gain. The newly-developed pan-genome has a total of 35,719 genes, a core genome of 16,821 genes and an average of 32,795 genes in each cultivar. The variable genes are enriched with environment responsive genes and classify the sorghum accessions according to their race. We show that 53% of genes display presence-absence variation, and some of these variable genes are predicted to be functionally associated with drought traits. Using more than two million SNPs from the pan-genome, association analysis identified 398 SNPs significantly associated with important agronomic traits, of which, 92 were in genes. Drought gene expression analysis identified 1,788 genes that are functionally linked to different conditions, of which 79 were absent from the reference genome assembly. This study provides comprehensive genomic diversity resources in sorghum which can be used in genome assisted crop improvement.

bioinformatics↗
bioRxiv2019

Occurrence of marine sponge Chelonaplysilla delicata Pulitzer-Finali & Pronzato, 1999 (Porifera: Demospongiae: Darwinellidae) from the Andaman Islands and the Indian Ocean: An indication of unexplored sessile habitat on mesophotic shipwrecks

During a biodiversity assessment on a wreck located in the Andaman Sea (Andaman Islands), a single specimen of sponge Chelonaplysilla delicata was recorded. Our finding confirms the species taxonomy and highlights the current observation as a first report from the Andaman Sea/ Indian Ocean. The baseline information of epifauna is further stated in this study.

ecology↗