RAPD Analysis Of Genetic Diversity In Fujian Banana Germplasm Resources

Banana is one of the most important subtropical fruit in Fujian Province, which has a long planting history and high economic value. Because of its asexual reproduction and polyploidy characteristic, its heredity background is complex and varieties are confused. In addition, there is seedless phenomenon in produces, which makes the difficulty in preserving and utilizing banana germplasm resources. Genetic diversity of 54 banana varieties in Fujian was studied by using the random amplified polymorphic DNA technique (RAPD). The main results were summarized as follows:1．Using the improved method of CTAB, high purity DNA was obtained from banana leaves.2．Optimize the RAPD-PCR system of banana. Based on the common RAPD reaction program and adjusting experiments, the optimal amplification program was described as follows: 94℃for 5min; 45 cycles at 94℃for 1 min, 38℃for 1 min and 72℃for 2 min; 72℃for 2min at last. PCR system (25μL total volume) contains: 20ng of genomic DNA, 200μmol/L of dNTP, 2．5μL of 10×PCR Buffer, 0．20μmol/L of primer, 0．75U Taq DNA polymerase, 17．85μL of ddH₂O.3．RAPD analysis of banana germplasm resources. 54 banana varieties were analyzed by RAPD with 16 random primers. A total of 194 DNA bands were amplified, among which 191 bands (98．45%) were polymorphic. The results showed high genetic diversity among banana varieties. Genetic similarity among banana varieties were obtained by SPSS 13．0, and molecular phylogenetic dendrogram of 54 banana varieties was established. According to GD=0．70 in the gendrogram, 54 materials were assigned to three clusters. The first cluster included 36 materials (Xiangyajiao group), the second included 11 materials (Fenjiao and Longyajiao in the majority) and the other included 7 materials (Dajiao group).4．4 special markers obtained from 16 primers can identify GuangdongZhanjiangJulongjiao, NanfengBajiao and Jiaojiao in wild. 5．21 banana materials were selected as core collection, which included Xiangyajiao, Fenjiaoand Dajiao group, and also included AAA, AAB, ABB and AA (HainanXigongjiao) genome.Besides familiar varieties, the new and rarity such as Zhangjiao 8, Shantoal longjiao andHainanBaxijiao, were included.