Amplified fragment length polymorphism analysis of the genetic variation of an endangered plant Lysimachia tashiroi (Myrsinaceae)

Lysimachia tashiroi Makino (Myrsinaceae) is an endangered perennial herb growing in moist places along riverbanks in restricted localities of Kyushu, Japan. The largest population known to date is located in Gokayama and is under threat of extinction because of the planned construction of a dam. To develop a conservation plan of the riverbank population of L. tashiroi in Gokayama, we examined genetic variation in the population using amplified fragment length polymorphisms (AFLPs). A related and widespread species, L. japonica, was included in the analysis. A total of 733 AFLP fragments were obtained from 73 accessions. An AMOVA for L. tashiroi showed that within-population and between-population variability were 62% and 38%, respectively. In addition, genetic variability was higher in L. tashiroi than in L. japonica. These results are unexpected because plants of L. tashiroi propagate vegetatively and seed fertility is very low in the Gokayama population. Based on our findings, we suggest that as many genets as possible should be transplanted to appropriate habitats neighboring the dam construction area.