| Summary: | 碩士 === 臺灣大學 === 農藝學研究所 === 98 === The purpose of this study was to establish the variety identification system of coffee in Taiwan by utilizing 10 morphological traits and ISSR and SSR molecular markers . The six C. arabica and C. canephora of HARC germplasm were used as reference, the DNA profile was established for the 160 coffee germplasm in Taiwan. According to the result of 10 morphological traits investigated, the frequency distribution of leaf length, leaf width, leaf shape, leaf area, length of plagiotropic internodes, the angle of the secondary branch at the insertion with the main one, seed length, seed width, seed shape, and seed thickness, except for leaf area, length of plagiotropic internodes, and seed thickness, the coefficient of variation of the others were estimated to be under 30%. Meanwhile, the trait of leaf area was a good indicator for discriminating between C. arabica and other species.
Thirty-two markers which showed polymorphism between species were identified from the 100 ISSR primers. The genetic similarity estimated by ISSR markers ranged from 0.19 to 1 between C. canephora and C. arabica accessions from HARC and Taiwan. The results showed ISSR markers could efficiently differentiate the Coffea species. In order to make up for the insufficient polymorphism between C. arabica cultivars, four polymorphic markers were identified after screened set of 53 SSR primers, which were then scored and used to estimate the genetic similarity and then clustering the C. arabica of HARC and of Taiwan. The result indicated the C. arabica germplasm could be divided into 4 groups: including Typica group, Bourbon group, Caturra group, and the unknown accessions, with the name after the known variety in the same cluster. Because of the narrow genetic base of C. arabica cultivars, the limited availability of the reference cultivars, the identified polymorphic markers, these markers were only able to discriminate the collected Taiwan C. arabica accessions into the same group as the reference Typica, Bourbon and Caturra variety.
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