A controlled vocabulary to describe crop traits in chickpea.

The Gene Ontology (GO) knowledgebase is the world's largest source of information on the functions of genes. This knowledge is both human-readable and machine-readable, and is a foundation for computational analysis of large-scale molecular biology and genetics experiments in biomedical research.

InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites.

Mapping of GO terms to InterPro entries.

LIS gene family phylogenetic tree files

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Gene annotations, on genome assembly

Synteny between cicar.CDCFrontier.gnm1 and other species.

Cowpea SNP positions on the cicar.CDCFrontier.gnm1 genome assembly from Varshney, et al. (2019)

Gene annotations from genome assembly

We have analysed the chickpea transcriptome in vegetative and flower tissues by exploiting the potential of high-throughput sequencing to measure gene expression. We mapped more than 295 million reads to quantify the transcript abundance during flower development. We detected the expression of more than 90% genes in at least one tissue analysed. We found quite a large number of genes were differentially expressed during flower development as compared to vegetative tissues. Further, we identified several genes expressed in a stage-specific manner.

Synteny between cicar.ICC4958.gnm2 and other species.

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LIS gene families

Drought tolerance is a complex trait that involves numerous genes. Identifying key causal genes or linked molecular markers can facilitate the fast development of drought tolerant varieties. Using a whole-genome resequencing approach, we sequenced 132 chickpea varieties and advanced breeding lines and found more than 144,000 single nucleotide polymorphisms (SNPs). We measured 13 yield and yield-related traits in three drought-prone environments of Western Australia. The genotypic effects were significant for all traits, and many traits showed highly significant correlations, ranging from 0.83 between grain yield and biomass to -0.67 between seed weight and seed emergence rate. To identify candidate genes, the SNP and trait data were incorporated into the SUPER genome-wide association study (GWAS) model, a modified version of the linear mixed model. We found that several SNPs from auxin-related genes, including auxin efflux carrier protein (PIN3), p-glycoprotein, and nodulin MtN21/EamA-like transporter, were significantly associated with yield and yield-related traits under drought-prone environments. We identified four genetic regions containing SNPs significantly associated with several different traits, which was an indication of pleiotropic effects. We also investigated the possibility of incorporating the GWAS results into a genomic selection (GS) model, which is another approach to deal with complex traits. Compared to using all SNPs, application of the GS model using subsets of SNPs significantly associated with the traits under investigation increased the prediction accuracies of three yield and yield-related traits by more than twofold. This has important implication for implementing GS in plant breeding programs.

We report a map of 4.97 million single-nucleotide polymorphisms of the chickpea from whole-genome resequencing of 429 lines sampled from 45 countries. We identified 122 candidate regions with 204 genes under selection during chickpea breeding. Our data suggest the Eastern Mediterranean as the primary center of origin and migration route of chickpea from the Mediterranean/Fertile Crescent to Central Asia, and probably in parallel from Central Asia to East Africa (Ethiopia) and South Asia (India). Genome-wide association studies identified 262 markers and several candidate genes for 13 traits. Our study establishes a foundation for large-scale characterization of germplasm and population genomics, and a resource for trait dissection, accelerating genetic gains in future chickpea breeding.

The Plant Ontology (PO) is a community resource consisting of standardized terms, definitions, and logical relations describing plant structures and development stages, augmented by a large database of annotations from genomic and phenomic studies.

A controlled vocabulary of describe phenotypic traits in plants.

The Sequence Ontology is a set of terms and relationships used to describe the features and attributes of biological sequence.