| Persimmon(Diospyos.kaki) is one deciduous tree belonging to genus Diospyros in the family Ebenaceae. It is one of the six main alternatives to oil and food crops of China with huge ecological, social and economic value. Henan province is one of the five main distubution areas of D. kaki all over national scale. In this area, rich varied germplasm accessions can be found. In this study, genetic diversity of the persimmon germplasms in Henan province was analyzed by phenotypic characteristics, content of different nutrient components and molecular markers based on germplasm survey and preservation. Identification of the germplasms and genetic relationship among different genetypes were elucidated according to phenotypic characteristics and molecular markers. Moreover, excellent varieties were selected according to phenotypic characteristics and content of different nutrient components. The main results of the study were as following.1. The persimmon germplasms of Henan province mainly distributed in mountainous and hilly areas which were agreement with the local landform. Luoyang and Sanmenxia(in west), Pingdingshan and Nanyang(in southwest) were main distribution areas. There were especially great number of resources in Luanchuan and Songxian county of Luoyang which lie in the north slope of Funiu Moutain.2. It was clear that there were ample phenotypic diversities in Henan persimmon germplasms with abundant different accession and high variability. The results indicated that(1) among all 146 persimmon germplasms, there were many variation types in 24 descriptive characteristics, 17 of which can be found all types and only ten types of seven descriptive characteristics were absent.(2) High degree and great range existed in 19 quantitative characteristics whose coefficient of variation ranged from 11.06% to 50.88% and the maximum were all over two times as much as the minimum.(3) The degree of variation in fruit was highest, then seed, the lowest was in leaf.(4) 43 phenotypic traits were divided into five groups by R cluster analysis which showed that different phenotypic traits assembled for one group if they were from the same tissue.(5) All germplasms were divided into five groups by Q cluster analysis and several cultivars such as ‘Niuxinshi’, ‘Shiliushi’ and ‘Huoshi’ with problem of homonym or synonym were identified according to the phenotypic traits.3. There was high variation and polymorphism in the content of vitamin C, total phenols, flavonoid and tannin in fruits of persimmon germplasms in Henan province, but it was revealed that the contents of the four components in most samples of Henan province reached the middle or low level.(1) The coefficients of variation about the four components were all over 50%.(2) The value of 0.46 mg/g was calculated in average vitamin C content, ranging from 0.04 mg/g to 2.28 mg/g and the average content of total phenols was 18.95 mg/g, ranging from 0.90 mg/g to 63.31 mg/g. The mean content of flavonoid and tannin was 12.64 mg/g and 11.75 mg/g, respectively. The minimum of flavonoid was 0.25 mg/g and the maximum was 53.35 mg/g, while the minimum and maximum of tannin was 0.74 mg/g and 40.18 mg/g.(3) There was highly significantly difference(P<0.01) in the content of vitamin C and total phenols among different regions, and significantly difference(P<0.05) was detected in the content of flavonoid, but there was no significantly difference in tannin content.(4) Highly significant positive correlation(P<0.01) was only showed among the three polyphenol components with the value all over 0.8. Moreover, the result of unary linear regression was verified better, regression equation were as following: y=0.723x-1.058(R2= 0.902, total phenols and flavonoid), y=0.487x+5.581(R2=0.748, total phenols and tannin), and y=1.917x-3.574(R2=0.676, tannin and flavonoid).(5) The number of excellent germplasms selected with high content of vitamin C, total phenols, and total flavonoid were 10, 29 and 24, respectively. The number of excellent germplasms with high and low content of tannin were 29 and 28. In addition,16 germplasms with high polyphenol content were selected.4. There was aslo high variation and polymorphism in the content of total phenols, flavonoid and tannin in leaves of the persimmon germplasms. There was significant difference both among different areas or samples. And the contents of the three components in most samples also reached the middle or low level.(1) The mean content of total phenols, flavonoid and tannin was 122.75 mg/g, 81.09 mg/g and 52.15 mg/g, respectively. The coefficients of variation about the three components were 30.56%, 46.85% and 27.58%.(2) The content of phenols mainly distributed at 103.87-144.25 mg/g, flavonoid 54.39-96.93 mg/g, and tannin 44.91-60.65 mg/g.(3) There was highly significantly difference in the three components content among different regions(P<0.01). The degree of variation of Luoyang was highest, then Nanyang and the north regions, and the lowest was Sanmenxia and Pingdingshan. The order of average content was the north regions, Nanyang, Pingdingshan/Sanmenxia, and Luoyang.(4) Significant positive correlation existed among the three component contents(P<0.01). Moreover, the result of unary linear regression was also better. The regression equations were as following: y=0.347x+9.556(R2=0.818, total phenols and tannin), y=0.88x-26.92(R2=0.754, total phenols and total flavonoid), y=0.322x+25.98(R2=0.726, tannin and total flavonoid).(5) The number of excellent germplasms with high content of total phenols, total flavonoid and tannin were 8, 11 and 14, respectively. In addition, 14 germplasms with high polyphenol content were selected. The number of different types among different areas were varied. It showed that there were most resources in Luoyang, and the types in this region was also most.5. It was revealed high level of genetic diversity among D. kaki germplasm accessions in Henan province with varied variations and high heterozygosity.(1) A total of 159 polymorphic DNA fragments i.e., bands, were obtained from all 102 accessions by 17 SSR loci with an average of 9.35 bands per pair of primers ranging from 5(8125/DC592401) to 14(ssr DK11/DQ097479 and ssr DK14/DQ097482). The number of band patterns was 508 in total with an average of 29.88 per pair of primers ranging from 8(5553/DC585710) to 53(ssr DK11/DQ097479). The total number of unique band pattern was 267 with an average of 15.71 per pair of primers ranging from 2(5553/DC585710) to 37(ssr DK11/DQ097479). The rate of unique band pattern ranged from 73.68% to 25.00% and the rate of germplasm identification ranged from 1.96% to 36.27%. The average value of polymorphism information content(PIC) was 0.8397 ranging from 0.4667 to 0.9647 and the average Shannon’s information index(I) was 2.6586 ranging from 1.1121 to 3.5967. Observe heterozygosity(Ho) ranged from 0.1471 to 0.9608 with an average value of 0.7774. It was showed that there were most high genetic diversity level in the three loci ssr DK11/DQ097479, ssr DK14/DQ097482 and m Dp17/EF567410 by comprehensive comparison.(2) The result obtained from principal coordinate analysis was roughly same as that from cluster analysis: There were obvious genetic differences among different species; all germplasms accessions of D. kaki were divided into the same group which was clearly different from the samples of other closely related species; the relationship between D. kaki and D. virginiana was relatively distant.(3) All germplasms tested including some homonymous or synonymous cultivars, such as ‘Niuxinshi’, ‘Bayuehuang’ and ‘Qiyuezao’, were identified by the 17 SSR primers. |
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