Ali Waqar, Grzybowski Marcin, Torres-Rodríguez J Vladimir, Li Fangyi, Shrestha Nikee, Mathivanan Ramesh Kanna, de Bernardeaux Gabriel, Hoang Khang, Mural Ravi V, Roston Rebecca L, Schnable James C, Sahay Seema
Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, USA.
Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, USA.
J Exp Bot. 2025 Sep 17;76(14):4141-4153. doi: 10.1093/jxb/eraf198.
Natural genetic variation in photosynthesis-related traits can help both to identify genes involved in regulating photosynthetic processes and to develop crops with improved productivity and photosynthetic efficiency. However, rapidly fluctuating environmental parameters create challenges for measuring photosynthetic parameters in large populations under field conditions. We measured chlorophyll fluorescence and absorbance-based photosynthetic traits in a maize diversity panel in the field using an experimental design that allowed us to estimate and control multiple confounding factors. Controlling the impact of day of measurement and light intensity as well as patterns of two-dimensional spatial variation in the field increased heritability for 11 out of 14 traits measured. We were able to identify high-confidence genome-wide association study (GWAS) signals associated with variation in four spatially corrected traits (the quantum yield of PSII, non-photochemical quenching, redox state of QA, and relative chlorophyll content). Insertion alleles for Arabidopsis orthologs of three candidate genes exhibited phenotypes consistent with our GWAS results. Collectively these results illustrate the potential of applying best practices from quantitative genetics research to address outstanding questions in plant physiology and to understand natural variation in photosynthesis.
光合作用相关性状的自然遗传变异有助于识别参与调节光合过程的基因，并培育出具有更高生产力和光合效率的作物。然而，快速波动的环境参数给在田间条件下测量大群体的光合参数带来了挑战。我们在田间的一个玉米多样性群体中测量了叶绿素荧光和基于吸光度的光合性状，采用的实验设计使我们能够估计和控制多个混杂因素。控制测量日期和光强的影响以及田间二维空间变异模式，提高了所测14个性状中11个的遗传力。我们能够识别与四个空间校正性状（PSII的量子产率、非光化学猝灭、QA的氧化还原状态和相对叶绿素含量）变异相关的高置信度全基因组关联研究（GWAS）信号。三个候选基因的拟南芥直系同源基因的插入等位基因表现出与我们的GWAS结果一致的表型。这些结果共同说明了应用数量遗传学研究的最佳实践来解决植物生理学中悬而未决的问题以及理解光合作用自然变异的潜力。
