Construction of Linkage Maps Using DNA Markers and Mapping of Useful Genes in Azuki Bean

连锁图谱的构建对有效挖掘植物遗传潜力具有重要意义。分子连锁图谱为育种工作中的遗传作图、基因标记和改良选择提供了便利。为此，本研究开展了以下工作，为小豆(Vigna angularis，2n=22)的进一步分子育种提供基础资料。1.利用赤小豆与其野生近缘V.nakashimae和赤小豆与水稻小豆(V.umellata)的种间杂交F_2群体构建了两个azuki连锁图谱。前者图谱由14个连锁群组成，共108个随机扩增多态DNA标记和19个RFLP标记，总图谱大小为1250 cM；后者由14个连锁群组成，共74个随机扩增标记和114个RFLP标记，覆盖1702 cM。根据共同作图标记的谱系，确定了这两个AUKKI种间图谱和绿豆(V.Radiata)图谱之间的保守连锁区块。3.在AZUKI连锁图谱上定位了形态标记和QTL。上胚轴颜色、角果颜色和角果碎角等5个主效基因被定位在赤小豆和中生小豆之间的种间图谱上。1个上胚轴颜色主效基因和多个QTL(抽穗天数、株高、粒重、抗褐飞虱等)的定位。在赤豆-稻豆图谱中进行了估计。4.利用赤小豆和稻豆杂交的重组自交系的生产正在进行中，以确定QTL的准确位置。

The construction of a linkage map is of fundamental importance for the efficient exploration of plant genetic potential. Molecular linkage map will facilitate genetic mapping, gene tagging and improved selection in breeding program. Therefore, in the present study, the followings were carried out to obtain the basic information on further molecular breeding of azuki bean (Vigna angularis, 2n=22). 1. Two azuki linkage maps were constructed with F_2 populations derived from the interspecific crosses between azuki bean and its wild relative, V.nakashimae, and between azuki bean and rice bean (V.umbellata). The former map consisted of 14 linkage groups with 108 RAPD and 19 RFLP markers and the total map size was 1250 cM.The latter contained 14 linkage groups with 74 RAPD and 114 RFLP markers covering 1702 cM.2. The conserved linkage blocks were identified between these two azuki interspecific maps and mungbean (V.radiata) map based on the lineage of the common mapped markers. 3. Morphological markers and QTLs were mapped in the azuki linkage maps. Five major genes controlling morphological characters, such as epicotyl color, pod color and pod shattering, were mapped in the interspecific map between azuki bean and V.nakashimae. The locations of one major gene for epicotyl color and several QTLs (days to heading, plant height, seed weight, bruchid resistance, etc...) were estimated in azuki-rice bean map. 4. Production of recombinant inbred lines from the cross between azuki bean and rice bean is now in progress to determine the precise locations of QTLs.