Relationship Of Red Flashed Crabapples By AFLP

The genus Malus is usually divided into apple and crabapple by the size of fruitinternational. Crabapple’s fruit is usually smaller than5cm.There are many crabapples thathas both red peel and flesh. The red material mainly anthocyanin. The pigmentation of typicalred apple fruits results from accumulation of anthocyanin. Anthocyanin is a flavonoids. Suchcompounds are strong antioxidants in vitro, with the effect on human health. Thus, red-fleshedcrabapple genotypes are an attractive starting point for development of novel varieties.However the fruit of crabapples is usually very small. The fruit of the domestic apple (Malus×domestica) is a popular and important source of nutrients, and is considered one of the top‘functional foods’—those foods that have inherent health-promoting benefits beyond basicnutritional value. However, cultivar development is limited by lack of characterization of thediversity of genetic backgrounds showing this trait. Traditional methods of identification (fieldtesting) rely on phenotypic traits that can be measured only at plant maturity and therefore takea long time to complete (3to5years). Molecular analyses of genotypic markers offer anattractive alternative or complement to identification based on phenotypic characters and canbe performed reliably at any stage of maturity, avoiding long study periods.AFLP is a PCR-based molecular marker, with the advantage that it could produce alarge number of polymorphisms in different regions of the genome. And it’s sensitive,reproducible It is commonly used in research of genetic variation of similar species. The aimof the present research was1) to fingerprint23red fleshed and3white fleshed Malusaccessions using AFLP analysis,2) to determine genetic relationships between them, and3)to find red related bands through AFLP process.This study intends to study red flesh crabapples, together with part of the apple cultivarsand wild species with AFLP markers to investigate their genetic diversity, relationship andorigin.Results are as follows.The main results of this research are listed as follows:1. Through test, we conclude a suitable system for AFLP analysis including theextraction of genomic DNA of tested materials and PCR. Different action time result indeferent results for AFLP analysis system. By comparison, In conclude, enzyme digestion andligation should not be applied separately, and the pre-amplification produce was also diluted10times with ddH2O and used for selective amplification.2. We chose four pairs of primers from64pairs of combinations, and they were M-CTC/E-AGC、M-CTA/E-ACG、M-CAT/E-ACT、M-CAA/E-ACG. Thirty accessions wereanalyzed. The four AFLP primer combinations amplified a total of94bands ranging from100to1000bp,92of which were polymorphic. The percentage of polymorphic bands was97.9%,with amplified DNA bands produced by each primer combination ranging from27to19andaveraging at28.5. The amplified DNA fragments varied with each primer combination. Thehighest (39) and lowest (28) number of DNA bands were amplified by M1/E6(M-CAA/E-ACG) and M5/E2(M-CTA/E-ACG). In conclude, a high level of genetic diversitywas detected, and AFLP analysis was successful in detecting genetic diversity anddetermining genetic relationships among30malus accessions. All the accessions could beuniquely distinguished from one another.3. A dendrogram was constructed using SM coefficient of similarity and the UPGMAclustering method. The similarity coefficient were between0.63-0.95. Using a thresholdvalue at0.65, the30accessions could be clustered into4groups. Group A contains M.‘Prairifire’, M.‘Louisa’, M.‘showtime’, M.‘Dolgo’, M.‘Sparkler’, M.‘Red Barron’and M.×domestica ‘Pink Lady’;Group B contains red fleshed hybrid like M.‘Hopa’, M.‘Liset’, M.‘Lemoinei’, M.‘Agate’, M.‘Royalty’, M.‘Pink spires’, M.‘Red Splender’, M.‘Flame’, M.‘Perfect Purple’, M.‘Indian Summer’and wild species like M. sieversii. Var.‘Niedzwetzkyana’, M. Asiatica. and M. Baccata.; Group C contains M.‘Indian Magic’, M.‘Cinnabar’, M. Sieboldii, M.×Zumi, M.‘Radiant’, M.‘Kelsey’ and M.‘Sargentii’. Group Dcontains M. Sieversii, M.×domestica ‘Fuji’and M.×domestica ‘Gala’.4. The hybrid cultivars sharing common parents tend to group together in cluster analysis,suggesting that the genetic similarity values obtained by molecular markers appear tocorrespond to the known pedigree information. For instance, M.‘fugi’ and M.‘Gala’ appearedclustered together, and M.‘Liset’ and M.‘Lemoinei’ clustered together in AFLP analysis.