应用RAPD和AFLP标记的方法对甜(辣)椒和番茄品种的多态性分析(英文)

Twenty-five accessions of pepper (Capsicum annuum) and twenty-two accessions of tomato (Lycopersicon esculentum) cultivated in primary province where the main agricultural breeding insititutes breed the majority improved varieties of pepper and tomato in China were analysed. RAPD and AFLP markers were performed and compared for their effectiveness to discriminate near relatives. In pepper varieties, AFLP markers generated by two primer combinations distinguished every pepper accessions. The percentage of polymorphic markers for AFLP was lower than that for RAPD(9% and 35 % respectively). However, the average numbers of polymorphic fragments were 2.2 per primer for RAPD and 5.1 per AFLP primer combination,respectively. Therefore AFLP primers were two times more efficient than RAPD primers in their ability to generate polymorphic markers in pepper varietes. In tomato varieties,the percentages of polymorphic markers were 5.5% for AFLP and 61% for RAPD single primer and 58% for RAPD two-primer,the percentage of polymorphic markers of AFLP was lower than that for RAPD. The average numbers of informative bands per primer were 4.2 for RAPD single primer and 4.4 for RAPD two-primer and 2.6 for AFLP primer combinations,respectively. The study demonstrated that RAPD markers were more useful than AFLP markers among nearly related tomato varieties. RAPD markers generated by one single primer and one two-primer reactions can discriminate 21 our of 22 tomato varieties. The effectiveness of various marker techniques for the two species C. annuum and L. esculentum is discussed.