Locating Of The Fruit Maturity Date Gene By Using SSR Markers In Peach [Prunus Persica(L.) Batsch]

The maturity date of peach fruit is an important trait for peach supply due to its unsuitablity for storage and transporting. Mapping the fruit maturity date genes has important significance for peach marker-assisted breeding.In this experiment self-crossed progenies from Okubo peach which is the main cultivar in north China, simple sequence repeats (SSR) markers and Bulked Segregant Analysis (BSA) strategy were used to locating the fruit maturity date genes in peach. The main results of this research were as followed:1.Screening 165 pairs of SSR primes from Prunus persica with two pairs Early/Late ripen DNA pools, three markers:BPPCT015, UDP97-402 and UDP96-003 showed stable different bands pattern between Early/Late ripen DNA pools were obtained.2.The associating relation between three markers BPPCT015,UDP97-402 UDP96-003 and fruit maturity date were confirmed by genotyping100 random progenies with three SSR markers above. Through single marker analysis method there were very significant difference in fruit maturity date among genotypes of the all the three marker. A local genetic map of the three markers was drawn used FsLinkageMap2.0 software, their sequence was BPPCT015,UDP97-402 and UDP96-003, the genetic distance between adjoining marker was 13.2 and 21.0cM, respectively. With reference to recent published Prunus genetic maps, all the three markers belong to linkage group 4. Using interval mapping method through FsQtlMap software this major quantitative trait locus (QTL) was further mapped between BPPCT015 and UDP97-402 with log of odds (LOD) value of 13.35, and heredity value of 0.623. The effect value of sigle gene in this locus is 15d.3. BPPCT015 and UDP97-402 were further tested in 88 peach accessions with different maturity date, amplification band types has good corresponding relation to phenotypes of fruit maturity date. The conformity percentages of BPPCT015 in early maturity varieties (fruit development period<75d) and late maturity varieties (fruit development period>120d) were 82% and 84%, respectively. The conformity percentages of UDP97-402 in early maturity varieties (fruit development period<75d) and late maturity varieties (fruit development period>120d) were 92% and 47%, respectively. This indicate BPPCT015 have higher distinguishing ability to both of the early maturity and late maturity of peach, and UDP97-402 have high distinguishing ability to early maturity of peach.The mapping of the major QTL that controlling the fruit maturity date of peach has significance in peach marker-assisted breeding.