Construction Of AFLP Fingerprint Maps And Classification Of Single Chromosomes Of Citrus Grandis Cv. Guanximiyou

Pomelo ( Citrus grandis (L.) Osbeck ) belongs to the class of Eucitrus. It is one of special fruit trees in China. However, it is difficult to construct an accurate physical map for pomelo due to its long growth cycle and complex genetic background. Therefore, it provides obstacles for further researches of pomelo in genomics and molecular biology.This experiment applied the methods of microdissection and microcloning to construct libraries of 48 single chromosomes of citrus grandis cv. Guanximiyou. This experiment also established an Amplified Fragment Length Polymorphism ( AFLP ) fingerprint maps. Using an NTsys software to analyzed the maps, all 48 single chromosomes of pomelo were classified systematically. Main results are shown as followings:1,An appropriate way to extract genomic DNA from pomelo was found, and genomic DNA of pomelo with high quality and purity was obtained. 48 single chromosomes were obtained by microdissection with fine glass needles.2,Single chromosomes of pomelo were amplified in vitro through two rounds of LA-PCR, and a library of 48 single chromosomes of pomelo was established. The most ideal three pairs of primer combinations out of 23 were screened out in order to amplify single chromosomes by AFLP.3,AFLP fingerprint maps of single chromosomes with a large number of polymorphic fragments were obtained by denaturing polyacrylamide gel electrophoresis ( PAGE ) and silver staining.4,The AFLP fingerprint maps were analyzed by NTsys, and then all 48 single chromosomes of pomelo were put into 13 categories.This study constructed AFLP fingerprint maps and classified single chromosomes of pomelo scientifically in molecular level. The maps also provided a large number of candidates of polymorphic fragments to screen out specific molecular markers for each single chromosome. This study had laid a foundation for constructing accurate physical maps of pomelo in the future. It also has significant theoretical and practical values for more extensive research in molecular genetics and genomics of pomelo.