| ‘Eshi 1’ and androecious genotype of Diospyros spp.are distributed in Dabie Mountain area in central China.Athough they carry the RO2 marker,which is linked to the allele associated with the non-astringent trait of Chinese pollination constant and non-astringent（CPCNA）persimmon,its application potential as the breeding parent of new PCNA is undefined.In this study,based on genetic breeding system of CPCNA,‘Eshi 1’ or Male 2 were used as the breeding parents for PCNA genotypes which can bear only female flowers by artificial hybridization pollination.Moreover,we identified the astringency type of hybrid individuals.The main results were as following（1）The pollen germination rate of ‘Eshi 1’ or Male 2 were no more than 10%.In addition,the fluorescence observations for pollen growth on stigma showed well pollen-stigma compatibility,and which was significantly higher between ‘Eshi 1’ and ?Soshu?（JPCNA）.A total of 2022 female flowers were performed for pollination,and 577 embryos were obtained through embryo rescue technique.Consequently,430 embryogenic test tube seedlings survived from three cross combinations.（2）Early identification of embryogenic test tube seedlings on the astringency traits and flower sexual were carried out by using RO2 and DlSx-AF4 S markers.And 87 target individuals with RO2 marker but without DlSx-AF4 S marker were obtained,which accounting for 23.5% in the F1 populations.（3）Shoots of 476 embryogenic test tube seedlings were top grafted on adult Diospyros lotus L.trees growing in greenhouse.313 of them survived and the average grafting survival ratio is 65.8%.In the top grafting experiment,the grafting survival rate of F1 drived from ?Soshu? × ‘Eshi 1’is highest,which is up to 80.4%.（4）Through comparison with the known genotypes of CPCNA,Japanese PCNA（JPCNA）and non-PCNA,the results of soluble/insoluble tannin content and tannin cell size measure exhibited that H8-2 [?Huashi 1?（pollination variant and astringent,PVA）× Male 8],H9-1（‘Eshi 1’ × Male 1）and H13-1 [‘Eshi 1’ × ?Taishuu?（Japanese PCNA）] belonging to PCNA genotypes,and others were non-PCNA.Furthermore,RO2 marker were detected in the three new PCNA genotypes.In conclusion,the ‘Eshi 1’ and androecious genotype Male 8 carries the dominant CPCNA gene locus,indicating their potential to be parents for the genetic improvement of PCNA persimmon.Moreover,novel PCNA genotypes may be created through fast PCNA genetic improvement technology. |
