Studies On The Production Of Nonaploid Seedless Pollination-Constant Nonastringent Persimmon (PCNA) By Pollination With 2n Egg

Japanese persimmon (Diospyros kaki Thunb.) belongs to the Diospyros genus, Ebenaceae Family. There are diploid (2n=2x=30), tetraploid (2n=4x=60), hexaploid (2n=6x=90), nonaploid (2n=9x=135) among persimmon(Diospyros spp.).All the Japanese persimmon(Diospyros kaki Thunb.) cultivars of pollination constant and non-astringent (PCNA) are hexaploid. Japanese persimmon could produce unreduced eggs. The discoveries of natural nonaploids and unreduced eggs make it possible to nonaploid persimmon breeding with unreduced eggs. The pollens ('Zenjimaru' and Luotian-tianshi', 2n=6x=90) were crossed with 'Fujiwaragosho'(D. kaki,2n=6x=90). Some plantlets were obtained. The main results of this study are as follows:1. The germination percentages of the'Fujiwaragosho' and 'Luotian-tianshi' pollen grains were Statisticed. Some pollen tubes grew and penetrated into the style. The fully developed seeds were obtained. It confirmed the cross compatibility in crosses between 'Fujiwaragosho' and 'Zenjimaru' or 'Luotian-tianshi'.2. The distribution pattern of pollens diameter in'Zenjimaru' and 'Luotian-tianshi'persimmon showed that 2n pollen was in 'Zenjimaru'. The 2n pollen was not observed in the 'Luotian-tianshi'.3. The resultant embryos were rescued by in vitro culture technique to obtain plantlets. Stomata of the two regenerated plantlets were larger than those of the normal plantlets, but the densities of stomata were reduced. The nuclear DNA contents of the two regenerated plantlets were one and a half times as much as normal hexaploid plantlets. The number of chromosomes in two regenerated plantlets root-tips was 135. These results proved that two regenerated plantlets were nonaploid (2n=9x=135).4. The two nonaploid plantlets were sufficiently confirmed to be hybrid by SSR analysis.