基于SRAP分子标记的冰草遗传连锁图谱构建

构建高密度遗传连锁图谱是冰草抗性、品质、产量等重要性状QTL精细定位及标记辅助育种研究的基础。该试验以四倍体杂交冰草F2群体的202个分离单株及其亲本为材料,利用SRAP分子标记技术和Join Map 4.0作图软件对冰草的遗传连锁图谱进行了构建。结果表明:(1)共筛选出22对多态性好、标记位点清晰稳定的SRAP适宜引物,对冰草杂种F2分离单株的基因组DNA进行PCR扩增,共获得510个SRAP多态性标记位点,其比率占88.2%。(2)偏分离分析表明,偏分离标记比率仅为14.12%,符合遗传作图的要求。(3)成功构建了冰草的SRAP分子标记遗传连锁图谱,该图谱有14个连锁群、510个标记,连锁群间长度范围86.4～179.0cM,覆盖基因组总长度1 912.9cM,标记间平均间距3.75cM,为高密度遗传图谱。

Construction of Genetic Linkage Map for Crested Wheatgrass (Agropyron) Based on SRAP Molecular Markers

To construct a high density genetic linkage map of crested wheatgrass is the basis of fine mapping for important QTLs such as resistance, quality and yield, as well as the marker assisted breeding research. In this research, with 202 individuals from F₂ segregation population of tetraploid hybrid crested wheatgrass and their parents as materials, we constructed a genetic linkage map of crested wheatgrass based on SRAP molecular marker technique and Join map 4.0 mapping software. The results revealed that: (1) a total of 22 SRAP suitable primers with good polymorphism, clear and stable bands were screened to make a wide range of PCR amplification on the genomic DNA of F₂ individuals. A total of 510 SRAP polymorphic markers were obtained, accounting for 88.2%. (2) The analysis of segregation distortion showed that the ratio of distorted markers was only 14.12%, which met the requirements of genetic mapping. (3) The genetic linkage map of SRAP molecular markers of crested wheatgrass was successfully constructed. The map consisted of 14 linkage groups, including 510 SRAP markers, and covered the whole genome of 1 912.9 cM. The map length of linkage groups ranged from 86.4 cM to 179.0 cM, and the average distance between markers is 3.75 cM. It is a high density genetic map.