Abstract:

【Objective】 The aims of this study were to construct a DNA fingerprinting database of major citrus cultivars, which could provide a possibility of establishment of a technical standard system for purity and authenticity identification of citrus nursery trees. 【Method】 Simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers were used to analyze the DNA fingerprinting of 102 citrus cultivars(lines) and then to choose suitable primers for the construction of DNA fingerprinting database of citrus cultivars (lines). 【Result】 12 SSR primer pairs, with high polymorphisms and good repeatability, regarded as specific primers, which could identify 42 cultivars (lines), were selected from 200 SSR primer pairs. Meanwhile, 40 ISSR primers were used to analyze the DNA fingerprinting of 60 cultivars (lines) that can not be distinguished by SSR markers and 2 ISSR specific primers were chosen. As a result, a total of 70 citrus cultivars (lines) could be identified by the 12 SSR primers and 2 ISSR primers. Finally, a DNA fingerprinting database containing 70 major citrus cultivars (lines) was constructed by using those 12 SSR and 2 ISSR primers. 【Conclusion】 The results indicated that SSR and ISSR markers are suitable for the construction of DNA fingerprinting database of citrus cultivars (lines). Moreover, the fingerprinting database will provide a basis for genetic purity and authenticity fast evaluation of citrus nursery trees.

Key words: citrus, cultivar identification, SSR, ISSR, fingerprinting database