Optimization Of Genetic Improvement Technology Based On Androecious In Chinese PCNA Persimmon

There are abundant persimmon cultivars in China, but the main cultivars are PCA persimmon. In this study, we used several androecious genotypes of Diospyros spp. found in Dabie mountain area of central China as male parents, which had RO2markers that linked with the natural deastringency characteristic of C-PCNA. The female parents were ’Mopanshi’and’Gongcheng-shuishi’. RO2marker was used to select the PCNA of hybrids in the early stage, and then grafted on the adult trees to further improve the Chinese PCNA persimmon rapid genetic breeding system. The main results were as follows:1. A total of970female flowers were tested,322fruits were harvested,370embryos were obtained and348plantlets were gotten from the6cross combinations (’Gongcheng-shuishi’ x Male type No.l,’Gongcheng-shuishi’ x Male type No.2,’Gongcheng-shuishi’ x Male type No.8,’Mopan-shi’x Male type No.8,’Eshi No.1’ x ’Taishuu’,’Taishuu’ x Male type No.8).The ploidy2. Identification of four male parents of different genotype was measured by the flow cytometry. The control was ’Luotian-tianshi’ known as hexaploid. The results showed that the peak value of ’Luotian-tianshi’ was151.99. While, the peak value of Male type No.1, Male type No.2, Male type No.8and Taishuu’ were148.20,150.47,151.25,144.10respectively, suggesting that four male parents of different genotype were hexaploid as well as ’Luotian-tianshi’.3. RO2maker was applied to testing two larger offspring of ’Gongcheng-shuishi’ x Male type No.2and ’Youhou’ x Male type No.8, electrophoresis results of which were counted. The result of chi-square test showed that the segregation behavior of RO2in both F1populations was consistent with a1:1ratio as previously reported.4. The sequence was identical to the RO2marker of Male type No.2and13offspring of ’Mopan-shi’ x Male type No.2is common with original sequence present in previously reported by Ikegami et al., suggesting that RO2marker could be expressed stably in progeny without mutation. 5. A preliminary analysis about the growth of rootstock after pruning suggested the time to grow tender tip in different seasons was not the same, the shortest was summer. In the tip grafting experiment, Fi of’Gongcheng-shuishi’ x Male type No.8and ’Youhou’ x Male type No.8were used as scion, the number were85and57respectively. The survival rate after30d was30.1%and19.3%.In summary, some of unique androecious genotypes in China had the potential to improve the major PVA persimmon cultivars in China. Combination of marker-assisted selection and tip graft would be applied in the genetic improvement system of Chinese PCNA persimmon.