Biology subjects

Waheed, M. T.

Publications and source records attributed to Waheed, M. T..

4 recordsLinked to original sources

bioRxiv2020

Agro-morphological, yield, and genotyping-by-sequencing data of selected wheat germplasm

Wheat (Triticum aestivum) is the most important staple food in Pakistan. Knowledge of its genetic diversity is critical for designing effective crop breeding programs. Here we report agro-morphological and yield data for 112 genotypes (including 7 duplicates) of wheat (Triticum aestivum) cultivars, advance lines, landraces and wild relatives, collected from several research institutes and breeders across Pakistan. We also report genotyping-by-sequencing (GBS) data for a selected sub-set of 52 genotypes. Sequencing was performed using Illumina HiSeq 2500 platform using the PE150 run. Data generated per sample ranged from 1.01 to 2.5 Gb; 90% of the short reads exhibited quality scores above 99.9%. TGACv1 wheat genome was used as a reference to map short reads from individual genotypes and to filter single nucleotide polymorphic loci (SNPs). On average, 364,074{+/-}54479 SNPs per genotype were recorded. The sequencing data has been submitted to the SRA database of NCBI (accession number SRP179096). The agro-morphological and yield data, along with the sequence data and SNPs will be invaluable resources for wheat breeding programs in future.

genetics↗

bioRxiv2020

Comparison among the first representative chloroplast genomes of Orontium, Lisa, Zamioculcas, and Stylochaeton of the plant family Araceae: inverted repeat dynamics are not linked to phylogenetic signaling

The chloroplast genome provides insight into the evolution of plant species. We de novo assembled and annotated chloroplast genomes of the first representatives of four genera representing three subfamilies: Lasia spinosa (Lasioideae), Stylochaeton bogneri, Zamioculcas zamiifolia (Zamioculcadoideae), and Orontium aquaticum (Orontioideae), and performed comparative genomics using the plastomes. The size of the chloroplast genomes ranged from 163,770-169,982 bp. These genomes comprise 114 unique genes, including 80 protein-coding, 4 rRNA, and 30 tRNA genes. These genomes exhibited high similarities in codon usage, amino acid frequency, RNA editing sites, and microsatellites. The junctions JSB (IRb/SSC) and JSA (SSC/IRa) are highly variable, as is oligonucleotide repeats content among the genomes. The patterns of inverted repeats contraction and expansion were shown to be homoplasious and therefore unsuitable for phylogenetic analyses. Signatures of positive selection were shown for several genes in S. bogneri. This study is a valuable addition to the evolutionary history of chloroplast genome structure in Araceae.

plant biology↗

bioRxiv2020

Complete chloroplast genomes of Anthurium huixtlense and Pothos scandens (Pothoideae, Araceae): unique inverted repeat expansion and contraction affect rate of evolution

The subfamily Pothoideae belongs to the ecologically important plant family Araceae. Here, we report the chloroplast genomes of two species of the subfamily Pothoideae: Anthurium huixtlense (163,116 bp) and Pothos scandens (164,719 bp). The chloroplast genome of P. scandens showed unique inverted repeats (IRs) contraction and expansion, which increases the size of the large single copy (102,956) region and decreases the size of the small single-copy (6779 bp) region. This led to duplication of many single-copy genes due to transfer to IR regions from the small single-copy (SSC) region, whereas some duplicate genes became single copy due to transfer to large single-copy regions. The rate of evolution of protein-coding genes was affected by the contraction and expansion of IRs; we found higher mutation rates for genes that exist in single-copy regions as opposed to IRs. We found a 2.3-fold increase of oligonucleotide repeats in P. scandens when compared with A. huixtlense, whereas amino acid frequency and codon usage revealed similarities. We recorded higher transition substitutions than transversion substitutions. The transition/transversion ratio was 2.26 in P. scandens and 2.12 in A. huixtlense. We also found a higher rate of transversion substitutions linked with non-synonymous substitutions than synonymous substitutions. The phylogenetic inference of the limited species showed the monophyly of the Araceae subfamilies. Our study provides insight into the molecular evolution of chloroplast genomes in the subfamily Pothoideae and family Araceae.

genomics↗

bioRxiv2020

Plastid genomics of Nicotiana (Solanaceae): insights into molecular evolution, positive selection and the origin of the maternal genome of Aztec tobacco (Nicotiana rustica)

The genus Nicotiana of the family Solanaceae, commonly referred to as tobacco plants, are a group cultivated as garden ornamentals. Besides their use in the worldwide production of tobacco leaves, they are also used as evolutionary model systems due to their complex development history, which is tangled by polyploidy and hybridization. Here, we assembled the plastid genomes of five tobacco species, namely N. knightiana, N. rustica, N. paniculata, N. obtusifolia and N. glauca. De novo assembled tobacco plastid genomes showed typical quadripartite structure, consisting of a pair of inverted repeats (IR) regions (25,323-25,369 bp each) separated by a large single copy (LSC) region (86,510 -86,716 bp) and a small single copy (SSC) region (18,441-18,555 bp). Comparative analyses of Nicotiana plastid genomes showed similar GC content, gene content, codon usage, simple sequence repeats, oligonucleotide repeats, RNA editing sites and substitutions with currently available Solanaceae genomes sequences. We identified twenty highly polymorphic regions mostly belonging to intergenic spacer regions (IGS), which could be appropriate for the development of robust and cost-effective markers to infer the phylogeny of genus Nicotiana and family Solanaceae. Our comparative plastid genome analysis revealed that the maternal parent of the tetraploid N. rustica was the common ancestor of N. paniculata and N. knightiana, and the later species is more closely related to N. rustica. The relaxed molecular clock analyses estimated that the speciation event between N. rustica and knightiana appeared 0.56 Ma (HPD 0.65-0.46). The biogeographical analysis showed a south-to-north range expansion and diversification for N. rustica and related species, where N. undulata and N. paniculata evolved in North/Central Peru, while N. rustica developed in Southern Peru and separated from N. knightiana, which adapted to the Southern coastal climatic regimes. We further inspected selective pressure on protein-coding genes among tobacco species to determine if this adaptation process affected the evolution of plastid genes. These analyses indicated that four genes involved in different plastid functions, such as DNA replication (rpoA) and photosynthesis (atpB, ndhD and ndhF), came under positive selective pressure as a result of specific environmental conditions. Genetic mutations of the following genes might have contributed to the survival and better adaptation during the evolutionary history of tobacco species.

genomics↗