Genetic architecture of node-specific leaf length and candidate gene identification in maize revealed by a temperate–tropical multiparental population

Genetic dissection and QTL validation of seedling root system architecture in Chinese wheat landraces

Mapping quantitative trait loci (QTLs) for plant architecture traits using a high-density genetic linkage map in diploid potato (Solanum chacoense)

Genome-Wide Association Study and Identification of Core Candidate Genes for Shoot and Root Length in Wheat During Germination

The genetic architecture and core candidate genes for shoot length (SL) and root length (RL) at the germination stage are dissected and seven core candidate genes for SL and 13 for RL are identified, including three pleiotropic genes regulating both traits.

Novel loci for flag leaf thickness with breeding potential: genetic dissection and candidate genes prediction

As a key morphological trait of flag leaves, flag leaf thickness (FLT) directly modulates light energy capture efficiency and per-unit-area photosynthetic capacity, and is thus identified as a critical regulator of wheat grain yield formation. Dissecting the genetic basis underlying FLT is of great significance for accelerating the molecular breeding of high-yield wheat varieties. In this study, two recombinant inbred line (RIL) populations were employed to map quantitative trait locus (QTL) for FLT across five independent environments. A total of 19 QTLs controlling FLT were identified in the two RIL populations. Among them, QFLT.suas-2CN-4B.2, QFLT.suas-2CN-6A, QFLT.suas-2SY-3B.2, and QFLT.suas-2SY-6A exhibited stable expression across multiple environments, and comparative analysis with previously reported QTLs indicated that all four loci are likely novel. Notably, QFLT.suas-2CN-6A and QFLT.suas-2SY-6A were co-localized within the same physical interval, suggesting they are likely the same locus. Candidate gene analysis for the co-localized locus QFLT.suas-2CN-6A and QFLT.suas-2SY-6A identified seven putative candidate genes highly expressed in wheat leaves, all of which encode chlorophyll a-b binding proteins that may participate in the regulation of FLT development. Furthermore, significant positive correlations between FLT and spikelet number per spike (SNS) were detected in both RIL populations. The favorable alleles of QFLT.suas-2CN-6A and QFLT.suas-2SY-6A significantly increased SNS by 3.21% and 3.31%, respectively. Collectively, these results deepen our understanding of the genetic basis underlying wheat FLT, and provide stable, valuable QTL resources and candidate gene targets for molecular marker-assisted breeding of high-yield wheat.

Genome wide association mapping and haplotype analysis identify genetic loci and candidate genes associated with yield related traits in rice (Oryza sativa L.)

Rice ( Oryza sativa L.) is one of the most important staple crops worldwide, and improving grain yield remains a major objective of rice breeding programs. Yield is a complex quantitative trait influenced by multiple agronomic characteristics, including grain yield per plant (GY), seed setting rate (SSR), plant height (PH), and thousand grain weight (TGW). In this study, a natural population comprising 265 rice accessions was evaluated during two consecutive growing seasons (2022-2023) at one field location, and genome-wide association studies (GWAS) conducted using 4454137 high-quality single nucleotide polymorphisms (SNPs). Best linear unbiased prediction (BLUP) values estimated across the two year-environments were used for association analysis using a mixed linear model (MLM). A total of 102 significant SNPs were identified and consolidated into 20 quantitative trait loci (QTLs), including five associated with GY, four with SSR, ten with PH, and one with TGW. Among them, several loci were co-localized with previously reported genes associated with yield related traits, thereby supporting the reliability of the GWAS results. Candidate gene identification and haplotype analysis further revealed four prioritized genes: LOC_Os09g28230 (GID1L2) for GY, LOC_Os05g09500 for SSR, LOC_Os03g06930 for PH, and LOC_Os02g09170 for TGW. Significant phenotypic differences among haplotypes supported the potential involvement of these genes in regulating the natural trait variation. These findings provide insights into the genetic basis of rice yield related traits and offer genetic resources for future validation and breeding. However, because the present study included only two year-environments at one field location, additional multi-environment validation is required before the broader environmental reproducibility or breeding adaptation.

Multi-Environment Multi-Locus Association Mapping Reveals Genomic Regions for Drought-Related Traits in Tropical Maize.

Maize grain yield is frequently constrained by water scarcity, particularly in tropical regions characterized by irregular rainfall patterns. Dissecting the genetic basis of drought-related traits remains challenging because their expression is strongly influenced by environmental conditions. In this study, we applied a multi-environment multi-locus genome-wide association study (MEML-GWAS) to identify genomic regions associated with drought-related traits in tropical maize. The association panel comprised 190 inbred lines from the Embrapa breeding program, which were genotyped with 500,108 GBS-derived SNPs, and crossed with two tester lines. Phenotypic data corresponded to the performance of the testcross hybrids, divided in Dent and Flint heterotic groups, evaluated across two years at two locations in Brazil under well-watered and water-stressed conditions. Traits analyzed included grain yield, anthesis-silking interval, female and male flowering time, and plant and ear height. Drought stress reduced grain yield by approximately 50% and increased the anthesis-silking interval by about two days. A total of 179 significant SNP-trait associations were detected, of which 166 showed significant SNP-by-environment interaction effects, while 13 displayed stable effects across environments. Several associations were detected specifically under water-stressed conditions, highlighting genomic regions potentially involved in drought adaptation. Functional annotation revealed candidate genes previously implicated in abiotic stress responses, including ZmTIP1, which encodes an S-acyltransferase regulating root hair development and drought tolerance. Among the novel candidate genes, GRMZM2G159125, encoding a phospholipase D, emerged as a particularly promising candidate due to its strong association with grain yield and its role in membrane lipid signaling pathways related to stress responses. Although a few associations overlapped genomic regions previously reported for drought tolerance in maize, most loci represent potentially novel genetic factors that may contribute to improving drought resilience in tropical maize breeding programs.