Research Article | Open Access

Volume 2024 |Article ID 0171 | https://doi.org/10.34133/plantphenomics.0171

Using UAV-Based Temporal Spectral Indices to Dissect Changes in the Stay-Green Trait in Wheat

Rui Yu,^1,2,5 Xiaofeng Cao,^2,5 Jia Liu,^1,2 Ruiqi Nie,^1,2 Chuanliang Zhang,^1,2 Meng Yuan,^1,2 Yanchuan Huang,^1,2 Xinzhe Liu,³ Weijun Zheng,¹ Changfa Wang,¹ Tingting Wu,³ Baofeng Su,³ Zhensheng Kang,^2,4 Qingdong Zeng ,^2,4 Dejun Han ,^1,2 Jianhui Wu ^1,2

¹College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
²State Key Laboratory of Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling, Shaanxi 712100, China
³College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
⁴College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
⁵These authors contributed equally to this work

Abstract

Stay-green (SG) in wheat is a beneficial trait that increases yield and stress tolerance. However, conventional phenotyping techniques limited the understanding of its genetic basis. Spectral indices (SIs) as non-destructive tools to evaluate crop temporal senescence provide an alternative strategy. Here, we applied SIs to monitor the senescence dynamics of 565 diverse wheat accessions from anthesis to maturation stages over 2 field seasons. Four SIs (normalized difference vegetation index, green normalized difference vegetation index, normalized difference red edge index, and optimized soil-adjusted vegetation index) were normalized to develop relative stay-green scores (RSGS) as the SG indicators. An RSGS-based genome-wide association study identified 47 high-confidence quantitative trait loci (QTL) harboring 3,079 single-nucleotide polymorphisms associated with SG and 1,085 corresponding candidate genes. Among them, 15 QTL overlapped or were adjacent to known SG-related QTL/genes, while the remaining QTL were novel. Notably, a set of favorable haplotypes of SG-related candidate genes such as TraesCS2A03G1081100, TracesCS6B03G0356400, and TracesCS2B03G1299500 are increasing following the Green Revolution, further validating the feasibility of the pipeline. This study provided a valuable reference for further quantitative SG and genetic research in diverse wheat panels.