Genetic identification and characterization of novel loci for flagleaf morphology traits in Chinese endemic wheat

https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/tpg2.70245?getft_integrator=clarivate&src=getftr&utm_source=clarivate

The Plant Genome，Volume 19, Issue 2

Md Nahibuzzaman Lohani， Longxing Su， Lu Lu， Li Yin ， Yanlin Liu，Qiang Xu ，Yunfeng Jiang，Qiantao Jiang，Guoyue Chen，Yuming Wei，Chunji Liu ， Quan Xie ，Jian Ma

Abstract

Flag leaf morphology (FLM) is a critical determinant of wheat (Triticum aestivumL.) photosynthetic efficiency and grain yield. Chinese endemic wheat, a uniquegenetic reservoir formed by long-term adaptation to diverse and heterogeneous envi-ronments in China, harbors abundant, untapped allelic variation for traits related toenvironmental resilience and yield architecture. Mining this distinctive germplasmis therefore essential for identifying novel genetic determinants underlying com-plex traits like FLM. In this study, a genome-wide association study was conductedon 182 Chinese endemic wheat accessions using 38,490 single-nucleotide poly-morphisms. We identified four stable quantitative trait loci (QTL) associated withFLM traits, three of which for flag leaf width (QFLW.sau.5A, QFLW.sau.5B, andQFLW.sau.5D) were intriguingly located on the homoeologous chromosomes ofgroup 5, suggesting the action of a conserved, multi-subgenome genetic system.None of these QTLs overlapped with previously reported loci, highlighting their nov-elty and the value of this endemic gene pool. Pleiotropic analysis revealed that theseloci also influence plant height and spike architecture. Their breeding value was fur-ther confirmed by validation in an independent population. Thirteen high-confidencecandidate genes with elevated expression in flag leaf tissue were predicted, many involved in leaf development, photosynthesis, and stress responses. Collectively, bymining the unique genetic diversity of Chinese endemic wheat, we have uncovereda novel, homoeologous QTL system and candidate genes for FLM. These findingsprovide both a conceptual advance in understanding the polyploid genetic architec-ture of this key trait and valuable functional targets/molecular markers for improvingphotosynthetic efficiency and yield potential in wheat breeding