Roots are important organs for plants to absorb water and nutrients, and good root structure can significantly improve water and nutrient use efficiency, enhance plant stress resistance, and play an important role in improving grain yield. Wheat is one of the most widely cultivated food crops in the world, and over the past century, breeders have significantly increased wheat yields through systematic selection for above-ground traits such as plant size, panicle and grain. Since the root system grows underground, it is not convenient to observe phenotype, and it is not a direct target trait for wheat breeding improvement, so it is still unknown whether modern breeding selection has an impact on root traits.
近日，西北农林科技大学农学院许盛宝教授团队在Plant Physiology上发表了题为“Modern wheat breeding selection synergistically improves above- and belowground traits”的研究论文，揭示了现代小麦育种改良通过选择能够同时调控地上性状和地下性状的遗传位点，从而协同改良了根系性状，为未来小麦根系结构遗传改良和产量提升提供了新思路。
In this study, 406 hexaploid wheat materials collected in the early stage were systematically identified and compared with seedling root phenotypes (Wang et al., 2022; Zhao et al. 2023), and found that the root system of modern cultivated varieties increased significantly compared with farm varieties, indicating that although the root system was not a direct target trait for wheat breeding improvement, it changed significantly in the process of breeding improvement. Furthermore, the correlation analysis between the aboveground agronomic traits and root phenotype in the population showed that there was a significant correlation between the two crops, and the correlation was stronger in the cultivated varieties (Fig. 1A-B), indicating that the root and aboveground traits changed synchronously during the breeding process.
Figure 1. Correlation between root system and aboveground phenotype. LA: Farmhouse species, MC: Modern cultivated species.
In order to explore the reasons for the synchronous change of wheat root and aboveground traits, this study used population genotype data to identify 44,979 linkage segments in the whole genome, and developed an evaluation method for the genetic effect of linkage segments on specific phenotypes based on a mixed linear model, and identified the "double effect segments" that had genetic effects on both aboveground and root traits. The results showed that the double-effect section was significantly enriched in the breeding selection area, and 90.74% of the haplotypes selected by breeding in the double-effect section could improve both aboveground and root traits in the direction of modern cultivated varieties, indicating that the wheat breeding process synergistically improved the aboveground and underground root traits by selecting haplotypes that could improve both aboveground and belowground traits.
In addition, the Wheat Genotype and Phenotype Database (WGPD) (http://resource.iwheat.net/WGPD/) was set up to integrate the data generated during the research process, such as aboveground and root related phenotypes, genotypes, gene expressions, and genetic effects of genomic linkage segments on each phenotype (Fig. 2), and provided query and download channelsIt provides data support for the study of other important agronomic traits in wheat.
Figure 2. Schematic diagram of the function of the wheat genotype and phenotype database.
Associate Professor Wang Xiaoming, Professor Xu Shengbao and Professor Cristobal Uauy of the John Innes Centre of Northwest A & F University and Professor Cristobal Uauy of the John Innes Centre are the co-corresponding authors of the paper, doctoral student Zhao Peng, graduated doctoral student Liu Zihui and young teacher Shi Xue are the co-first authors of the paper Dr. Simmonds was involved in the project. This work was supported by the China Postdoctoral Science Foundation (2021T140566), the National Key Laboratory of Crop Stress Resistance and Efficient Production, the High Performance Computing Platform of Northwest A&F University, and the Crop Biology Innovation Center.
参考文献：Wang X, Zhao P, Guo X, Liu Z, Ma X, Zhao Y, Lai X, Huang L, Wang W, Han D, Kang Z, Xu S (2022) Population transcriptome and phenotype reveal that the Rht-D1b contribute a larger seedling roots to modern wheat cultivars. bioRxiv: 2022.2006.2002.494553.Zhao P, Ma X, Zhang R, Cheng M, Niu Y, Shi X, Ji W, Xu S, Wang X (2023) Integration of genome-wide association study, linkage analysis, and population transcriptome analysis to reveal the TaFMO1-5B modulating seminal root growth in bread wheat. The Plant Journal 116: 1385-1400.
Paper link: https://doi.org/10.1093/plphys/kiae270
At the forefront of plant science, focusing on the frontier progress of plant science, the release of information, recruitment information and method software sharing. For submission and recruitment, please reply to "Submission" in the background, which are free of charge; For business cooperation, please contact WeChat ID: zwkxqy;