用Xa23的近等基因系CBB23及其感病輪回親本JG30構(gòu)建了包含2562個單株的F2作圖群體。通過分析571個感病單株，找到2個新的與Xa23基因連鎖的SSR標記RM187和RM206，它們與Xa23之間的遺傳圖距分別為7.1cM和1.9cM。通過篩選1200個RAPD引物，獲得2個與Xa23基因連鎖的RAPD標記RpdH5和RpdS1184，與Xa23之間的遺傳圖距分別為7.0cM和7.6cM。利用豐富占/CBB23、綠油占/CBB23兩個實際育種F2群體，結(jié)合抗病性人工接種鑒定，測算了RpdS1184、RM206和RpdH5用于分子標記輔助選擇 (MAS)的可能性。結(jié)果表明，對于豐富23群體，RpdH5和RpdS1184的MAS準確率分別為91.0%和87.3%，如果同時使用這兩個標記，可使MAS的準確率達99%。對于綠油23群體，RpdH5、RpdS1184和RM206的MAS準確率分別為77.1%、81.1%和80.8%。同時使用RpdH5、RpdS1184標記的MAS準確率為90.3%%；同時使用RpdH5、RM206的準確率為91.3%;同時使用RpdH5、RM206、RpdS1184標記的準確率為90.8%。
A F2 population , with 2562 individuals , of JG30/CBB23 was constructed for molecularmapping of the bacterialblight resistance gene Xa23 in rice .After screening 1200 random amplified polymorphic DNA (RAPD)primers , we foundRAPD markers , RpdH5 and RpdS1184, were linked to the Xa23 gene , with genetic distance of 7.0 cM and 7 .6 cM , respectively.Two simple sequence repeats (SSR)markers , RM187 and RM 206 , were also found to be linked to the Xa23gene , the genetic distance were 7 .1 cM and 1 .9 cM , respectively .The marker-assisted selection (MAS)efficiency ofRpdS 1184, RM 206 and RpdH5 was evaluated using two true breeding F2 populations .The results showed that the MASefficience of RpdH5 and RpdS1184 , in population Fengfu23 , were 91 .0 %and 87 .3 %, respectively , but the MAS efficiencyreached as high as 99 %when these two markers were co-used .For population Luyou 23, the MAS efficiency ofRpdH5 , RpdS1184 and RM 206 were 77 .1%, 81 .1 %and 80 .8 %, respectively .When RpdH5 and RpdS1184 were coused, the MAS efficiency was 90 .3 %;when RpdH5 and RM 206 were co-used, the MAS efficiency was 91 .3 %;whenRpdH5, RM 206 and RpdS1184 were co-used , the MAS efficiency was 90.8 %.