利用分子标记鉴定大麦Yd2基因型及其在育种辅助选择中的应用

Identification of Yd2 Genotype in Barley with Molecular Markers and Their Application in Molecular Marker-assisted Selection

研究分子标记鉴定大麦抗黄矮病基因Yd2的有效性,可为Yd2基因在大麦抗病育种中的广泛应用提供快速有效的分子辅助选择工具。利用与Yd2基因紧密连锁的YLM、CAPS-Ylp和ASPCR-Ylp标记同时检测52份国内外大麦品种(系)与4份大麦F1杂种的Yd2基因型,同时结合生物学抗性检测的表型分析其有效性。通过对Yd2基因型已知的20份大麦品种(系)及4个F1杂种的Yd2基因型分析,表明YLM、CAPS-Ylp与ASPCR-Ylp标记可以有效判断大麦Yd2基因型。进一步用这3个标记检测32份Yd2基因型未知的大麦的基因型,鉴定出基因型为Yd2-/Yd2-的品种(系)27份,基因型为Yd2+/Yd2+的品种(系)5份。在回交育种的分子辅助选择实例中,从BC2F2世代中选出了16个基因型为Yd2+/Yd2+的单株。3个分子标记结合应用能够快速有效地鉴定大麦Yd2基因型,可用于Yd2基因回交育种中的大规模分子标记辅助选择。

The objectives of this study were to assess the feasibility of molecular markers YLM,CAPS-Ylp,and ASPCR-Ylp used in Yd2 gene identification in barley and to provide a rapid and effective marker-assisted selection（MAS） method for facilitating the application of Yd2 gene in resistance breeding to barley yellow dwarf virus（BYDV） in barley.The three markers were used to detect the Yd2 genotypes in fifty-two barley cultivars（lines） and four hybrids of F1 generation.The resistance identification was performed to confirm the Yd2 genotypes of these cultivars（lines）.Moreover,the three markers were applied to select the plants with Yd2 gene in a practice resistant-breeding program.The three markers could identify successfully the Yd2 genotypes of twenty barley lines and four F1 hybrids with known Yd2 genotypes.This result confirmed that the effectiveness of the three markers in identification of Yd2 genotypes in barley.In 32 barley cultivars（lines） with unknown Yd2 genotype,the three markers revealed Yd2^-/Yd2^- genotype in 27 cultivars（lines） and Yd2^＋/Yd2^＋ genotype in the remaining five cultivars（lines）.In a breeding practice aiming at BYDV resistance improvement,16 positive plants with Yd2^＋/Yd2^＋ genotype were selected rapidly and successfully from the BC2F2 population using MAS approach.We suggest the cooperative application of the three markers in selecting Yd2 gene and genotype from a large scale of lines in barley backcross populations to ensure the accuracy and efficiency of MAS.