Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Genes (Basel). 2019 Apr 18;10(4):307. doi: 10.3390/genes10040307.
Wheat is a staple food commodity grown worldwide, and wheat starch is a valuable source of energy and carbon that constitutes 80% of the grain weight. Manipulation of genes involved in starch synthesis significantly affects wheat grain weight and yield. plays an important role in starch synthesis and its main function is granule formation. To mine and stack more favorable alleles, single nucleotide polymorphisms (SNPs) of , , and were investigated across 362 wheat accessions by Ecotype-Targeting Induced Local Lesions IN Genome (EcoTILLING). As a result, a total of 38 SNPs in the amplified regions of three genes were identified, of which 10, 15, and 13 were in , , and , respectively. These 38 SNPs were evaluated by using KASP and six SNPs showed an allele frequency >5% whereas the rest were <5%, i.e., considered to be minor alleles. In the Chinese mini core collection, three haplotypes were detected for TaSSIV-A and three for TaSSIV-B. The results of an association study in the Chinese mini core collection with thousand grain weight (TGW) and spike length (SPL) showed that Hap-2-1A was significantly associated with TGW and Hap-3-1B with SPL. Allelic frequency and geographic distribution indicated that the favored haplotype () has been positively selected in Chinese wheat breeding. These results suggested that the Kompetitive Allele Specific PCR (KASP) markers can be applied in starch improvement to ultimately improve wheat yield by marker assisted selection in wheat breeding.
小麦是全球广泛种植的主要粮食作物，小麦淀粉是一种有价值的能源和碳源，占谷物重量的 80%。参与淀粉合成的基因的操纵显著影响小麦籽粒重量和产量。SSIV 蛋白在淀粉合成中起重要作用，其主要功能是颗粒形成。为了挖掘和积累更多有利的等位基因，通过生态型靶向诱导局部基因组损伤（EcoTILLING）在 362 个小麦品种中研究了 、 、 基因的单核苷酸多态性（SNP）。结果，在三个 基因的扩增区域共鉴定出 38 个 SNP，其中 10、15 和 13 个分别位于 、 和 中。使用 KASP 对这 38 个 SNP 进行了评估，其中 6 个 SNP 的等位基因频率>5%，其余的<5%，即被认为是次要等位基因。在中国迷你核心品种中，检测到 TaSSIV-A 的三个单倍型和 TaSSIV-B 的三个单倍型。在中国迷你核心品种与千粒重（TGW）和穗长（SPL）的关联研究结果表明，Hap-2-1A 与 TGW 显著相关，Hap-3-1B 与 SPL 显著相关。等位基因频率和地理分布表明，有利的单倍型（）在中国小麦育种中已经被正向选择。这些结果表明，竞争性等位基因特异性 PCR（KASP）标记可应用于淀粉改良，最终通过小麦育种中的标记辅助选择提高小麦产量。
