EcoTILLING Reveals Natural Allelic Variations in Starch Synthesis Key Gene TaSSIV and Its Haplotypes Associated with Higher Thousand Grain Weight
EcoTILLING Reveals Natural Allelic Variations in Starch Synthesis Key Gene TaSSIV and Its Haplotypes Associated with Higher Thousand Grain Weight
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EcoTILLING 揭示了淀粉合成关键基因 TaSSIV 的自然等位变异及其与较高千粒重相关的单倍型
DOI：
10.3390/genes10040307
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发表时间：
2019-04-01
期刊：
影响因子：
3.5
通讯作者：
Liu, Luxiang
中科院分区：
文献类型：
--
作者：
Irshad, Ahsan;Guo, Huijun;Liu, Luxiang
小麦是世界范围内种植的主要粮食商品，小麦淀粉是构成谷物重量80%的有价值的能源和碳源。操纵淀粉合成相关基因显著影响小麦粒重和产量。TaSSIV在淀粉合成中起重要作用，其主要功能是形成颗粒。为了挖掘和叠加更有利的等位基因，利用EcoTILLING技术对362份小麦材料TaSSIV-A、B和D基因的单核苷酸多态性（SNP）进行了分析。结果，在三个TaSSIV基因的扩增区域中鉴定出总共38个SNP，其中分别在TaSSIV-A、B和D中有10、15和13个。通过使用KASP评估这38个SNP，并且6个SNP显示等位基因频率>5%，而其余的<5%，即，被认为是次要等位基因。在中国微核心种质中，TaSSIV-A和TaSSIV-B分别检测到3种单倍型。对中国小型核心种质的千粒重和穗长的关联分析结果表明，Hap-2-1A与千粒重显著相关，Hap-3-1B与穗长显著相关。等位基因频率和地理分布表明，在中国小麦育种中，有利的单倍型（Hap-2-1A）已被正向选择。这些结果表明，竞争等位基因特异性PCR（KASP）标记可以应用于小麦淀粉改良，通过分子标记辅助选择最终提高小麦产量。
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. TaSSIV 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 TaSSIV-A, B, and D 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 TaSSIV genes were identified, of which 10, 15, and 13 were in TaSSIV-A, B, and D, 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 (Hap-2-1A) 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.