Yang Xiaoping, Shaw Ranjan K, Li Linzhuo, Jiang Fuyan, Fan Xingming
College of Agriculture, Yunnan University, Kunming, 650500, China.
Institute of Food Crops, Yunnan Academy of Agricultural Sciences, Kunming, China.
BMC Plant Biol. 2025 Jan 24;25(1):105. doi: 10.1186/s12870-025-06125-5.
Starch is the most abundant carbohydrate in maize grains, serving as a primary energy source for both humans and animals, and playing a crucial role in various industrial applications. Increasing the starch content of maize grains is beneficial for improving the grain yield and quality. To gain insight into the genetic basis of starch content in maize kernels, a multiparent population (MPP) was constructed and evaluated for starch content in three different environments.
The integration of QTL mapping and genome-wide association analysis (GWAS) identified two SNPs, 8_166371888 and 8_178656036, which overlapped the QTL interval of qSC8-1, identified in the tropical maize line YML46. The phenotypic variance explained (PVE) by the QTL qSC8-1 was12.17%, while the SNPs 8_166371888 and 8_178656036 explained 10.19% and 5.72% of the phenotypic variance. Combined GWAS and QTL analyses led to the identification of two candidate genes, Zm00001d012005 and Zm00001d012687 located on chromosome 8.
The candidate gene Zm00001d012005 encodes histidine kinase, which is known to play a role in starch accumulation in rice spikes. Related histidine kinases, such as AHK1, are involved in endosperm transfer cell development in barley, which affects grain quality. Zm00001d012687 encodes triacylglycerol lipase, which reduces seed oil content. Since oil content in cereal kernels is negatively correlated with starch content, this gene is likely involved in regulating the starch content in maize kernels. These findings provide insights into the genetic mechanisms underlying kernel starch content and establish a theoretical basis for breeding maize varieties with high starch content.
淀粉是玉米籽粒中最丰富的碳水化合物，是人类和动物的主要能量来源，并在各种工业应用中发挥关键作用。提高玉米籽粒的淀粉含量有利于提高籽粒产量和品质。为深入了解玉米籽粒淀粉含量的遗传基础，构建了一个多亲本群体（MPP），并在三种不同环境下对淀粉含量进行了评估。
数量性状基因座（QTL）定位与全基因组关联分析（GWAS）相结合，鉴定出两个单核苷酸多态性（SNP），即8_166371888和8_178656036，它们与热带玉米品系YML46中鉴定出的QTL区间qSC8-1重叠。QTL qSC8-1解释的表型变异（PVE）为12.17%，而SNP 8_166371888和8_178656036分别解释了10.19%和5.72%的表型变异。GWAS和QTL分析相结合，鉴定出位于8号染色体上的两个候选基因Zm00001d012005和Zm00001d012687。
候选基因Zm00001d012005编码组氨酸激酶，已知其在水稻穗部淀粉积累中起作用。相关的组氨酸激酶，如AHK1，参与大麦胚乳转移细胞发育，影响籽粒品质。Zm00001d012687编码三酰甘油脂肪酶，可降低种子油含量。由于谷物籽粒中的油含量与淀粉含量呈负相关，该基因可能参与调控玉米籽粒中的淀粉含量。这些发现为籽粒淀粉含量的遗传机制提供了见解，并为培育高淀粉含量的玉米品种奠定了理论基础。
