Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, Haidian, China.
College of Agronomy, Agricultural University of Hebei, Baoding, 071001, China.
Theor Appl Genet. 2023 Feb 5;136(1):24. doi: 10.1007/s00122-023-04309-x.
We cloned and developed functional markers for the SiCHLI gene, which is responsible for the yellow-green color of leaves in foxtail millet, a frequently used marker trait in the hybrid breeding of foxtail millet by using bulked segregant analysis sequencing and haplotype analysis on the F and core-collected nature populations. The color of leaves has been widely used as a marker for the hybrid breeding of foxtail millet; however, few related gene have been cloned to date. Here, we used two F populations generated from crosses between the highly male-sterile material 125A with yellow-green leaves, and CG58 and S410, which have green leaves, to identify the genes underlying the yellow-green color of the leaves of foxtail millet. The leaves of 125A seedlings were yellow-green, but they became green at the heading stage. The content of chlorophyll a and chlorophyll b was lower, the number of thylakoid lamellae and grana was reduced, and the chloroplasts was more rounded in 125A than in S410 at the yellow-green leaf stage; however, no differences were observed between 125A and S410 in these traits and photosynthetic at the heading stage. Bulked segregant analysis and map-based cloning revealed that the SiCHLI gene is responsible for the leaf colors of 125A. A nonsynonymous mutation (C/T) in exon 3 causes yellow-green leaves in 125A at the seedling stage. Haplotype analysis of the SiCHLI gene in 596 core collected accessions revealed a new haplotype associated with high photosynthetic metabolic potential at the heading and mature stages, which could be used to enhance sterile lines with yellow-green leaves. We developed a functional marker that will facilitate the identification of foxtail millet accessions with the different types of yellow-green leaves. Generally, our study provides new genetic resources to guide the future marker-assisted or target-base editing in foxtail millet hybrid breeding.
我们克隆并开发了 SiCHLI 基因的功能标记，该基因负责谷子叶片的黄-绿颜色，这是谷子杂种优势育种中常用的标记性状，我们使用了 bulked segregant analysis 测序和 F 群体和核心收集自然群体的单倍型分析。叶片颜色已广泛用于谷子的杂种优势育种；然而，迄今为止，很少有相关基因被克隆。在这里，我们使用了两个 F 群体，它们是由高度雄性不育材料 125A（叶片黄-绿）与 CG58 和 S410（叶片绿）杂交产生的，用于鉴定谷子叶片黄-绿颜色的相关基因。125A 幼苗的叶片为黄-绿色，但在抽穗期变为绿色。在黄-绿叶片阶段，125A 中的叶绿素 a 和叶绿素 b 含量较低，类囊体片层和基质片层的数量减少，叶绿体更圆；然而，在抽穗期，125A 和 S410 之间在这些特性和光合作用方面没有差异。Bulked segregant analysis 和基于图谱的克隆表明，SiCHLI 基因负责 125A 的叶片颜色。第 3 外显子中的非同义突变（C/T）导致 125A 在幼苗期出现黄-绿叶片。对 596 个核心收集材料的 SiCHLI 基因的单倍型分析表明，一个新的单倍型与抽穗期和成熟期高光合代谢潜力相关，可用于增强黄-绿叶片不育系。我们开发了一个功能标记，将有助于鉴定具有不同类型黄-绿叶片的谷子材料。总的来说，我们的研究为谷子杂种优势育种中的标记辅助或目标碱基编辑提供了新的遗传资源。
