Microsatellite variability within and among local landrace populations of tea, Camellia sinensis (L.) O. Kuntze, in Kyoto, Japan

Abstract

Genetic variability within and among eight landrace populations of tea (Camellia sinensis (L.) O. Kuntze) located in southern Kyoto, Japan, was surveyed with six microsatellite markers. The aver- age number of alleles per locus was 3.83 to 4.67 for landrace populations, whereas the corresponding value among modern cultivars and breeding lines was 6.63. Expected heterozygosity values averaged over loci within landrace populations ranged from 0.498 to 0.723. A similar level of variation, 0.682, was observed for cultivars and breeding lines. High fixation index values (0.177-0.417) for each popula- tion are consistent with biparental inbreeding within the population. Genetic differentiation among local populations was extremely low with FST = 0.062, although AMOVA revealed significant differentiation among landrace populations. We propose that these populations share a common ancestral gene pool and that some degree of artificial selection within each population has been performed by local farmers. Neighbor-joining analysis revealed that genetic rela- tionships among populations reflect geographical location of populations. This might result from more frequent genetic exchange by nearby farmers.