The Molecular Markers And Sequences Analysis Of The Red Color In Fruit Fresh Of Peach [Prunus Persica(L.) Batsch]

Peach is an important and a model species for the study on wood fruits in the Rosaceae family.Currently many research efforts have been focused on building saturated genetic linkage maps fromwhich gronomically important traits can be located. Several genetic linkage maps of intraspecific orinterspecific crosses in Prunus L. have been constructed and have been integrated in one T×E map withwith562markers. DNA markers and genome regions that are conserved among species are very usefulin map-based cloning of genes, marker-assisted selection （MAS） in breeding programs, and comparativemapping among related species.Prunus persica （L.） Batsch has a long life cycle. It takes more than10years to cultivate a newvariety by using traditional breeding methods. In addition, P. persica （L.） Batsch trees are very tall, so itneeds to take up a lot of land for hybrid selection. In recent years, molecular marker-assisted breedingtechnology has attracted increasing attention, which can effectively shorten the breeding cycle of P.persica （L.） Batsch. A large number of researches were conducted on the molecular markers forcharacters of P. persica （L.） Batsch. In molecular markers for peach flesh characters, to be specific,yellow/white flesh, hairy/hairless, non-sour/sour tasteand fruit ripening characters had been studied.However, no research has been reported on molecular markers for the distribution of anthocyanins indifferent parts of fruit.In this study, SRAP and SSR markers combining with the BSA method were used for selection ofmolecular markers linked with the distribution of anthocyanins in different parts of fruit.. The resultswere shown as follows:1.SRAP is a new molecular marker which could provide high polymorphism and plentifulinformation. It is simple and has not the specie-specific character. It had been widely used for geneticdiversity, comparing genome analysis and map construction. The annealing temperature which affect theSRAP-PCR reactions was optimized in order to establish the SRAP molecular marker systemintemperatre fruits. The optimum system was as follows: the annealing temperature in the first5cycleswas41℃. the annealing temperature in the following30cycles was52℃. Amplications of this systemwere carriyed out with4primers on4varieties of peach. The results showed that the system was steadyand reliable.2.The distribution of anthocyanin in the fruit flesh of peach is different and the genetic mechanismis complex. The distribution of anthocyanin in the different local of fruit flesh of peach such as fleshunder the skin, middle flesh and flesh around the stone was investigated from the cross Chongyanghong ×Yanhong for years. Based on the results, the sequence-related amplified polymorphism （SRAP） andSimple Sequence Repeats（SSR） by the way of bulked segregate analysis （BSA） were applied toconstruct a local genetic linkage map for the gene determined the distribution of anthocyanin in the fruitflesh of peach. This map, comprising four SRAP markers, five SSR markers and the anthocyanindensity loci. Four dominant SRAP markers （Me01Em08、Me05Em03、Me07Em02and Me07Em04） andfive dominant SSR markers （UDP97-402、BPPCT023、UDP96-003、CH04g09、CPPCT028） linked tothe locus of the gene determined the distribution of anthocyanin in the flesh. One dominant SRAPmarkers （Me07Em02） linked to the loci of the gene determined the color around the stone（Cs） atdistances of0.0cM,. These markers would provide an effective tool for marker assisted selection for thetrait of the anthocyanin intensity in the fresh of peach.3. The molecular marker of Me07Em02linked to the Cs locus was tested in another progeniesfrom the cross of chongyanghong×Okubao, this marker linked to the Cs at a genetic distance of2.1cM.Extraction of the fragment amplified with the SRAP primer of Me07Em02and sequencing5clones with T7/SP6, the result showed that the fragment length is110bp. The sequence as follows（primer sequences underlined）:TGAGTCCAAACCGGTCCTGCTCAAGTGGAACCACATTGAGAACATGGCGCTCTAGCAGAGTGCAAAATAAGCAACTCTTTCAGTCTGCCATTGCAAATTCGTACGCAGTCThe result of BLASTn with the sequence of Peach v1.0showed that this sequence is a single copysequence located on scaffold₄of Peach v1.0. The analysis result using the software of DNAMANindicated that the maximum ORF is108bp, coding36amino acid, the amino acid sequence isSPNRSCSSGTTLRTWRSSRQNKQLFQSAIANSYAV and no similar sequence was found in theprotein database of GenBankThe sequences of marker of Me01Em08, Me05Em03and Me07Em04were also obtained. Thesequence of Me01Em08is the copia-like retrotransposon of peach, the other, Me05Em03may bethe gene of putative calcium-transporting ATPase13.4. The whole sequence of peach copia-like retratranposon was obtained located on the Peach v1.0genome of Scaffold-1. The whole sequence is5008bp and codes1535amino acid. The LTR length is444bp. The molecular marker based on the retrotransposon was obtained and application to the analysisof the diversity on peach.