’Shuangdongmi’ Peach Genetic Identification And Relationship Between The Related Hormones And Cell Morphology With Freestone In Fruit Ripening

This study was conducted in the laboratory of Horticulture College of Qingdao Agricultural University from 2014 to 2016.Genetic identification of peach cultivar ’Shuangdongmi were analyzed by morphological traits and SSR markers.Using the freestone cultivar ’Shuangdongmi’ and clingstone cultivar’Dongxuemi’ as experiment materials,we investigated the relationship between the arrangement and morphological changes in cells close to the stone and freestone.In addition,the content of abscise acid,gibberellin and ethylene production in sarcocarp near the stone was determined,and its relation to freestone was also analyzed.The main results are as follows:1.There are no other significant differences in leaf morphology and fruit quality between ’Shuangdongmi’and its parents ’Qingzhoumi’ and ’Dongxuemi’,except that the fruit is significantly much bigger than its parents.The result indicated that the new cultivar not only inherited the good qualities from its parents but also generated new good trait.Furthermore,eight pairs of SSR primers were selected with high polymorphism,one of which further validated the genetic relationship between new cultivar and its parents,and 2 of which could distinguish between new cultivar and its parents.2.With the fruit ripening,the freestone degree was gradually increased in ’Shuangdongmi’ fruit,and the stone surface became smooth without adhesion pulp at 14 days before fruit ripening.Cell morphology close to the stone changed from round to long strip with fruit maturation,and the numbers of long strip cell continued to increase after fruit ripening.However,there is no obvious changes observed in cell morphology of clingstone fruit.The results showed that the morphological changes of cells close to the stone had a great relationship with freestone character.3.Abscise acid content and ethylene production of sarcocarp near the stone increased with fruit maturation in both ’Shuangdongmi’ and ’Dongxuemi’,and the former reached its highest at 14 days before fruit ripening,which was much earlier than the latter.While gibberellin content decreased with fruit ripening in both freestone and clingstone cultivar,however,it was significantly higher in clingstone fruit than that in the freestone one before fruit ripening.The results indicated that gibberellin content might greatly relatted to freestone and clingstone character.