Biology subjects

Gangashetty, P.

Publications and source records attributed to Gangashetty, P..

3 recordsLinked to original sources

bioRxiv2025

Dissecting genomic regions and candidate genes for pod borer resistance and component traits in pigeonpea minicore collection

BackgroundPigeonpea is an important leguminous food crop primarily grown in tropical and subtropical regions of the world and is a rich source of high-quality protein. The biotic (weed, disease, and insect-pests) and abiotic stresses have significantly reduced the production and productivity of pigeonpea. Helicoverpa armigera, also known as pod borer, is a major pest in pigeonpea. A substantial investigations needed for comprehending the genetic and genomic underpinnings of resistance to H. armigera. Genetic improvement by genomics-assisted breeding (GAB) is an effective approach for developing high yielding H. armigera resistance cultivars. Still yet, no genetic markers and genes linked to this key trait have been detected in pigeonpea. In this context, a set of 146 pigeonpea minicore accessions were evaluated for four H. armigera resistance component traits namely pod borer resistance (PBR), days to 50% flowering (DF), days to maturity (DM), and grain yield (GY) for three consecutive seasons under field conditions. ResultsPhenotypic data of pod borer resistance and component traits, along with the whole-genome resequencing (WGRS) data for 4,99,980 SNPs, were utilized to perform multi-locus genome-wide association study (GWAS) analysis. Two models (SUPER, and FarmCPU) detected 14 significant marker-trait associations (MTAs) for PBR and three component traits. The MTAs with significant effect were mainly identified on chromosomes CcLG02, CcLG04, CcLG05, CcLG07 and CcLG11. These MTAs subsequently delineated with key candidate genes associated with pod borer resistance (Probable carboxylesterase 15, microtubule-associated protein 5, FAR1-RELATED SEQUENCE, and Omega-hydroxypalmitate O-feruloyl transferase 4), days to maturity (RING-H2 finger protein ATL7 and Leucine-rich repeat receptor-like protein kinase), and grain yield (Secretory carrier-associated membrane protein, and Glutaredoxin-C5 chloroplastic). ConclusionThese research findings reported significant MTAs and candidate genes associated with pod borer resistance and component traits. Further lab-based pod bioassay screening identified four minicore accessions, namely ICP 10503, ICP 655, ICP 9691 and ICP 9655 (moderately resistance genotypes), showing least damage rating and larval weight gain %, compared to the susceptible checks. After validating the significant MTAs, the associated SNP markers can be effectively utilised in indirect selection, which offers potential gains for such quantitative traits with low heritability and can improve insect management more sustainably. The significant MTAs, candidate genes and resistant accessions, reported in this study may be utilized for the development of pod borer-resistant pigeonpea varieties.

plant biology↗

bioRxiv2023

Glutaredoxin regulation of primary root growth confers early drought stress tolerance in pearl millet

Seedling root traits impact plant establishment under challenging environments. Pearl millet is one of the most heat and drought tolerant cereal crops that provides a vital food source across the sub-Saharan Sahel region. Pearl millets early root system features a single fast-growing primary root which we hypothesize is an adaptation to the Sahelian climate. Using crop modelling, we demonstrate that early drought stress is an important constraint in agrosystems in the Sahel where pearl millet was domesticated. Furthermore, we show that increased pearl millet primary root growth is correlated with increased early water stress tolerance in field conditions. Genetics including GWAS and QTL approaches identify genomic regions controlling this key root trait. Combining gene expression data, re-sequencing and re-annotation of one of these genomic regions identified a glutaredoxin-encoding gene PgGRXC9 as the candidate stress resilience root growth regulator. Functional characterization of its closest Arabidopsis homolog AtROXY19 revealed a novel role for this glutaredoxin (GRX) gene clade in regulating cell elongation. In summary, our study suggests a conserved function for GRX genes in conferring root cell elongation and enhancing resilience of pearl millet to its Sahelian environment.

plant biology↗

bioRxiv2018

Response to early drought stress and identification of QTLs controlling biomass production under drought in pearl millet

Pearl millet plays a major role in food security in arid and semi-arid areas of Africa and India. However, it lags behind the other cereal crops in terms of genetic improvement. The recent sequencing of its genome opens the way to the use of modern genomic tools for breeding. Our study aimed at identifying genetic components involved in early drought stress tolerance as a first step toward the development of improved pearl millet varieties or hybrids. A panel of 188 inbred lines from West Africa was phenotyped under early drought stress and well-irrigated conditions. We found a strong impact of drought stress on yield components. This impact was variable between inbred lines. We then performed an association analysis with a total of 392,493 SNPs identified using Genotyping-by-Sequencing (GBS). Correcting for genetic relatedness, genome wide association study identified QTLs for biomass production in early drought stress conditions and for stay-green trait. In particular, genes involved in the sirohaem and wax biosynthesis pathways were found to co-locate with association loci. Our results open the way to use genomic selection to breed pearl millet lines with improved yield under drought stress.

plant biology↗