Optimization Of Genetic Improvement System And Creation Of New Germplasm In Chinese PCNA Persimmon

There are various persimmon(Diospyros kaki Thunb.) cultivars existing in China, but most of them belong to Pollination Constant Astringent(PCA) type. The status of lacking new Pollination Constant Non-astringent(PCNA) type of Chinese patent needs to be improved. In the present study, based on the preliminary genetic improvement system of rapid PCNA breeding, we investigated the best cross parents’ selection, suitable pollination and bagging remove time. The following results may provide scientific evidence for Chinese PCNA persimmon breeding.1) The observation of flowering behaviour of the two cross combination parents indicates that male flowers usually bloomed 2-3 d earlier than female flowers on the same individual plant;In general, blooming phase of female flowers(7 to 8 days) was earlier than that of male flowers(11 to 14 days), in addation, full-bloom stage of female flowers and male flowers were 2-3 d and 5 d, respectively. Both of the flowering time of the two cross combination parents were just the same. Four days after pollination, stigmas of ‘Gongcheng-shuishi’ and ‘Taishuu’ were severely brown and inviscid, which indicated bag removing time of 4 d after pollination had no effect on pollination.2) 1200 plantlets were gotten from the cross combination of ‘Gongcheng-shuishi’×Male type No. 2, and the survival rate in text tube was about 90%. There were 569 individuals with RO2 marker, and the chi-square test demonstrated RO2 marker has a segeration rato of 1:1 in the progenies.3) 282 shoots without roots were grafted with tender tip, and 54 of them were survived with the grafting survival rate of about 19%.4) Among 15 fruiting plants of H1(‘Huashi No. 1’בLuotian-tianshi’), H2(‘Huashi No. 1’×Male type No. 2) and H3(‘Eshi No. 1’בLuotian Tianshi’), H3-8 was PCNA which has excellent quality, while H2-9 and H3-2 were PCA, H1-66, H1-67, H1-70, H1-71, H1-76 were PVNA, and the others were PVA.In summary, it is rather hopeful to improve main PCA cultivars heredity by taking our country unique and precious stminate germplasms as male parent, combining Chinese PCNA rapid genetic improvement breeding system. H3-8 is a created germplasm with the nature deastringency characteristics and excellent quality, which is a good candidate for becoming the first new variety of PCNA with our own intellectual property right. It is of great significance for optimizing the breeding system of Chinese PCNA to clearly grasp the optimal time for pollination, bag removing and grafting, enhance the yield of seed production and obtain more hybrid seeds.