Biology subjects

Abbai, R.

Publications and source records attributed to Abbai, R..

3 recordsLinked to original sources

bioRxiv2025

Genomic analysis uncovers unique haplotype signatures from subspecies and agronomic types associated with blanchability in groundnut

Blanchability, defined as the ease of seed coat removal after roasting, is a vital trait for enhancing processing efficiency and product quality in groundnut (Arachis hypogaea L.). To enable a comprehensive haplotype-level genetic dissection of this trait, SNPs derived from whole-genome resequencing (WGRS) were used to perform genome-wide association study (GWAS) using multi-locus models (BLINK and FarmCPU) on a diverse groundnut mini-core collection phenotyped across two crop seasons. A total of 26 significant SNP-trait associations (STAs) were identified across multiple chromosomes, with major loci on chromosomes Ah05, Ah06, and Ah17, some of which were further validated using KASP (Kompetitive Allele-Specific PCR) markers. Candidate genes, such as those involved in cell wall biosynthesis (e.g., galactoside 2-alpha-L-fucosyltransferase-like protein, protein kinase superfamily members, and glycerophosphoryl diester phosphodiesterase 3), were found to be within linkage disequilibrium (LD) of the identified STAs, suggesting their plausible association with blanchability. Haplo-pheno analyses identified superior high-blanchability haplotypes; Ah05HapBL3, Ah06HapBL5, Ah06HapBL10, and Ah17HapBL6, which were predominantly found in the fastigiata subspecies (including Valencia and Spanish bunch agronomic types) from South Asia and South America, while the low-blanchability haplotypes were from hypogaea subspecies (including Virginia runner and Virginia bunch agronomic types) from Africa. Overall, this study provides valuable insights for customizing blanchability through haplotype-based breeding of processing-grade cultivars thereby improving groundnut value chains to meet diverse industrial demands.

genomics↗

bioRxiv2025

Mapping Fusarium Wilt and Sterility Mosaic Disease Resistance-Associated Genomic Regions and Haplotype Variants in Pigeonpea

The occurrence of fusarium wilt and sterility mosaic disease in genial conditions causes significant yield losses in pigeonpea. The present genome-wide association study (GWAS) was employed on 176-genotype panel to identify candidate genomic regions associated with FW and SMD resistance in pigeonpea. A total of 869,447 filtered SNP markers were used for GWAS analysis. GWAS analysis identified significant genomic regions for FW on chromosomes 05, 10, and 11 and for SMD on chromosome 09. Four resistant sources, namely, ICP20096, ICP20097, ICPL87119 and ICP13304 were identified as a resistance source for both FW and SMD. Total 12 markers from chromosome 11 for FW and 4 markers from chromosome 09 for SMD were validated using the KASP genotyping approach. We have identified resistant haplotypes for FW on chromosome 10 and 11 and for SMD on chromosome 09. Moreover, we have identified four InDels for FW on chromosome 5 in Two component response regulator gene (Cc_11098) and four InDels for SMD on chromosome 9 in genes, namely, LRR and NB-ARC domain disease resistance protein (Cc_21069), Flavonoid 3, 5-hydroxylase (Cc_21070) respectively. For FW, Cc_10507586 region from chromosome 5 is identified in ICPL87119 and ICPL20096 donors. A region Cc_21637656 from chromosome 11 is identified in the ICPL87119 but not in the ICPL20096. Similarly, a region Cc_4438493 from chromosome 10 is identified in the ICPL20096 but not in the ICPL87119. For SMD, Cc_24131177 region is identified in both the SMD resistance donors (ICPL20096 and ICPL87119). Ccsmd04 region from chromosome 4 has been identified in ICPL87119 but not in the ICPL20096. These genomic regions can be brought together into single elite genetic background with the help of the markers identified in this study. The validated markers and donor lines in this study offer valuable tools and resources for the genetic improvement of pigeonpea cultivars with enhanced FW and SMD resistance.

genomics↗

bioRxiv2023

Balancing grain yield trade-offs in 'Miracle-Wheat'

Introducing variations in inflorescence architecture, such as the Miracle-Wheat (Triticum turgidum convar. compositum (L.f.) Filat.) with a branching spike, has relevance for enhancing wheat grain yield. However, in the spike-branching genotypes, the increase in spikelet number is generally not translated into grain yield advantage because of reduced grains per spikelet and grain weight. Here, we investigated if such trade-offs might be a function of source-sink strength by using 385 RILs developed by intercrossing the spike-branching landrace TRI 984 and CIRNO C2008, an elite durum (T. durum L.) cultivar; they were genotyped using the 25K array. Various plant and spike architectural traits, including flag leaf, peduncle and spike senescence rate, were phenotyped under field conditions for two consecutive years. On Chr 5AL, we found a new modifier QTL for spike-branching, branched headt 3 (bht-A3), which was epistatic to the previously known bht-A1 locus. Besides, bht-A3 was associated with more grains per spikelet and a delay in flag leaf senescence rate. Importantly, favourable alleles viz., bht-A3 and grain protein content (gpc-B1) that delayed senescence are required to improve grain number and grain weight in the spike-branching RILs. In summary, achieving a balanced source-sink relationship might minimise grain yield trade-offs in Miracle-Wheat. HIGHLIGHTGenetic interplay between sink number and post-anthesis source activity limits grain yield in the spike-branching Miracle-Wheat.

plant biology↗