Construction Of78Mango Germplasm Fingerprinting

Mangifera indica L. commonly known as mango, the most important member of Anacardiaceae Mangifera, is a famous tropical and subtropical evergreen fruit trees, enjoying the " the king of tropical fruits " reputation. Mango is one of the five famous fruits in the world. This paper adopted AFLP, ISSR molecular marker technique to detect a part of mango germplasm DNA polymorphism between different areas in China. The tested DNA materials electrophoresis was comparative analyzed and identified specific bands among various germplasm. In order to explore the mango germplasm resource genetic relationship, fingerprinting was constructed. It could provide the basis reference for germplasm identification, new varieties registration, registration and protection of property rights and other aspects of new varieties. It lay a foundation for further construction of mango fingerprint database. The main results were as follows:1.78mango accessions were studied for the analysis of genetic verity by the AFLP PCR system and DNA fingerprinting was constructed by AFLP molecular marker. The results indicated that78accessions could be separated by9primer combinations (M1E1, M1E3, M2E3, M3E1, M3E4, M4E3, M6E1, M6E4, M7E4). The primers amplified908reproducible fragments with an average of100.89and794bands were polymorphic in nature. A total of42specific sites were detected with the ratio of4.63%, including25mono bands,17missing bands. It meant that the specific bands could separate21from78accessions.Polymorphism ratio was87.44%. The highest proportion of polymorphic primer combination was M1E3(97.59%) and minimum ratio of polymorphism primer combination was M3E1(82.18%). The most specific fragments were amplified by primer combinations M3E4and M6E4. GSC among the78accessions ranged from0.603to0.913with an average of0.735. The accessions were clustered into five major groups by unweighted pair-group method with arithmetic averages.2.12high and repeatability ISSR primers were selected from100primers. The12selected primers amplified a total of148scorable fragments among78accessions with an average of12.3. The percentage of polymorphic bands was95.95%. GSC among the78accessions ranged from0.4272to0.8644with an average of0.761.855as preferred primer amplified19bands. When GSC0.612as the threshold,78mango accessions were clustered into five major groups by unweighted pair-group method with arithmetic averages.3.78mango accessions were comprehensive cluster analyzed by AFLP and ISSR. When the GSC threshold was0.706, the tested78mango accessions could be divided into5major groups. As the result, different geographical origin accessions were formed in different groups and the accessions from the same area formed in different subsets of taxa. It was clear that the two markers had a consistent place, but also had different place. They helped to more fully clarify the mango classification results, and they could not replace each other, mutually combine and confirm each other.4. In this study,78mango accessions'AFLP fingerprinting were constructed by AFLP marker.6pairs of AFLP primers with high polymorphism, good repeatability, high resolution were selected as benchmark of primer, with the letters A, B, C, D, E, F for the6pairs primers. They were M1E1(A), M1E3(B), M3E1(C), M3E4(D), M6E1(E), M7E4(F), respectively. Chose the amplified region with high polymorphism of the fingerprint, and encoded the fragments from largest to smallest, Thus, each species could be formed a barcode, which composed of six letters and numbers, the barcode was the fingerprint of the species.5. The ISSR results showed that6accessions with mono bands were selected by12pairs of screened primers. They were Guire mango284, M. hiemaeis, Honghua local mango, Hongping mango, Guandao mango, Guixiang mango. As list above, the first4accessions contained specific bands and the last two accessions with no specific bands in AFLP amplification. Constructed ISSR fingerprinting was further verification and supplement of AFLP fingerprinting from another perspective.6. Preliminary screening21with specific band accessions out of78accesions. They were Longzhou Thailand mango, Longjing damang Yuanjiang ivory, Wenchang baiyu, Longmang, Ai mang, Hongping mango, Yangmang, M. hiemaeis, M. persiciformis and so on.