普通小麦TaDep1基因克隆与特异性标记开发

OsDep1 (dense and erect panicle 1)控制水稻产量性状，影响穗长、直立性和着粒密度。根据水稻OsDep1基因序列，采用同源克隆技术克隆了普通小麦第5同源群染色体上的TaDep1基因，它包含5个外显子和4个内含子，与水稻OsDep1基因结构相似。TaDep1-A1、TaDep1-B1和TaDep1-D1的编码序列长度分别为918、888和900 bp，编码305、295和299个氨基酸残基。在普通小麦品种中检测到5个TaDep1-A1等位变异、4个TaDep1-B1等位变异和2个TaDep1-D1等位变异。根据TaDep1-A1和TaDep1-B1位点不同等位变异间的SNP和InDel，开发了3对显性互补标记和1个共显性标记，可以准确鉴别不同等位基因。共显性标记dep19是根据TaDep1-B1第5外显子一个30 bp的InDel开发的，可准确区分TaDep1-B1c与TaDep1-B1a、TaDep1-B1b和TaDep1-B1d。用这些标记对406份小麦品种进行检测，不同基因型的千粒重、株高、穗长、小穗数和穗节间均差异不显著，说明TaDep1基因与我国现有小麦品种的产量性状相关不显著。

Characterization of Dense and Erect Panicle 1 Gene (TaDep1) Located on Common Wheat Group 5 Chromosomes and Development of Allele-Specific Markers

Dense and erect panicle 1 (OsDep1) gene is an important QTL controlling yield associated traits such as panicle length, erect type, and grain density in rice. In the present study, full-length genomic DNA sequences of TaDep1 on common wheat group 5 chromosomes were cloned by homologous cloning approach based on the sequences of rice OsDep1. TaDep1 has five exons and four introns, similar to that of rice OsDep1. The coding sequences of TaDep1-A1, TaDep1-B1, and TaDep1-D1 were 918, 888, and 900 bp, encoding polypepetides of 305, 295, and 299 amino acids, respectively. Five allelic variants on TaDep1-A1 locus, four on TaDep1-B1 locus, and two on TaDep1-D1 locus were identified. Three pairs of complementary dominant markers and one codominant marker were developed based on the sequence polymorphisms presented in allelic variants of TaDep1-A1 and TaDep1-B1. The codominant marker dep19, which can accurately discriminate the allelic variants of TaDep1-B1c from those of TaDep1-B1a, TaDep1-B1b,and TaDep1-B1d, was developed from a 30 bp InDel of different allelic variants at the fifth exon of TaDep1-B1. No significant association was found among the yield associated traits such as thousand-kernel weight, plant height, panicle length, spikelet number and spikelet spacing in 406 cultivars, indicating that these genes have no significant effect on the yield-related traits in current Chinese wheat cultivars.