摘要： 利用分子标记技术，在许多作物上已获得了高密度的分子遗传图谱，并定位了许多主要农艺性状的QTL，而在牧草上这方面的研究尚属空白。为提高育种中对牧草产量性状优良基因型选择的效率，对高丹草的单株产量及其构成因素(株高、分蘖数、叶片数)进行QTL定位，确定其在染色体的位置及其遗传效应，探讨其杂种优势产生原因。在以高粱413A和棕壳苏丹草杂交获得的248个F_2：3家系构建的作图群体中，应用AFLP和RAPD两种标记技术构建了高丹草(Sorghum×Sudan grass)的遗传连锁图谱。共包含18个标记，分布于10个连锁群，图谱总长度为83 cM，标记间平均图距为4.98 cM。采用Joinmap/QTL4.0对高丹草单株产量及其三大构成因素进行QTL定位。共检测到QTLs19个，分布在8个连锁群上，其中，第1和3连锁群最多，各为4个和3个。单个QTL解释性状表型变异的5.20%～51.50%。检测到的19个QTL中，表现加性效应的有1个，占5.2%，部分显性效应的有3个，占15.79%，显性效应的有个，占31.58%，超显性效应的有9个，占47.3%。超显性效应和显性效应在高丹草杂种优势的遗传基础中占主导地位。

关键词: 高丹草, 遗传图谱, 产量性状, 分子标记, QTL定位

Abstract: Molecular genetic map were constructed on many crops and main agronomic characters were located on the chromosomes with QTL, the research had done little on the grass. In order to get high yield, the individual biomass and related factors (height, tillers and leaves number) were located on the chromosomes and analyzed genetic effect with QTLs. The heterotic vigor was discussed. The mapping population derived from Sorghum×Sudan grass (314A ZKSD) F_2:3 family, 248 indivduals were sampled, and with AFLP and RAPD markers to construct which covered 10 linkage groups with 836 cM distance. The average distance between markers were 4.98 cM. The software Joinmap/QTL4.0 were used for statistics analysis. The 19 QTLs were tested on 8 linkage groups. No. 1 and No. 3 linkage group covered 4 and 3 QTLs separately. Single QTLs explain 5.20%-51.50% phenotype difference. In the 19 QTLs, 1 QTL (5.26%) express the additive effect, 3 QTLs (15.79%) had partly dominant effect, 6 QTLs (31.58%) had dominant effect, 9 QTLs (47.36%) had super dominant effect. In showed super dominant effect and dominant effect had main action in Sorghum×Sudan heterotic basis.

Key words: Sorghum×, Sudan grass, Genetic map, Yield character, Molecular marker, QTL localization

中图分类号: 

• S544.1353

• S514.035.3