Abstract:

Genetic diversity and genetic differentiation of l6 Cephalotaxus fortunei provenances from main distribution area were analyzed using ISSR molecular markers. The result showed that there existed a high degree of genetic diversity for C. fortunei. Total gene diversity was 0.337 7 It was found that there was significant difference in genetic diversity among provenances. Provenances from the eastern and mideastern distribution area had higher genetic diversity. Small population effect, restricted gene flow and habitat fragmentation resulted in high genetic differentiation among provenances, which contributed to 25.9% of total genetic variation, and the differentiation within provenances contributed to 74.1% of total genetic variation. Analysis of Nei's unbiased genetic distance showed that provenances with higher genetic diversity from eastern and mideastern distribution area were aggregated. Genetic diversity difference between provenances from the central and the fringe distribution area might be attributed to difference between provenances of longleaf types and shortleaf types. The test also showed there was no significant correlation between genetic and geographic distances among provenances.

Key words: Cephalotaxus fortunei, provenance, genetic diversity, genetic differentiation, ISSR PCR