Araki, Kiwako , Yamada, Etsuko , Ohara, Masashi .
Demographic genetic studies of a clonal plant Convallaria keiskei: roles of clonal growth and sexual reproduction.
Clonal plants can produce offspring ramets by both sexual reproduction and clonal growth. Because individual genets consist of genetically identical ramets in clonal plants, it is difficult to address population biology studies at inter- and intra-genet level. In this study, to evaluate roles of both reproductions of a rhizomatous clonal plant Convallaria keiskei, we performed field works and genetic analysis. We established a large-scale study plot (100m*90m) and two fine-scale plots within the plot. In the large-scale plot, we detected genotypes for samples corrected from a shoot nearest to each 5m grid point. In the fine-scale plots, all ramets were marked and genotypically identified for five years. Survival and flowering of them were also monitored. Then, we excavated rhizomes to observe connections between mother and offspring ramets. Total 94 genotypes were detected at 282 grid points in the large-scale plot. The largest clone expanded to more than 40m. In the fine-scale plots, most of two-leaf (later life-history stage) ramets were identified by predominant genotypes found at large scale. Among small one-leaf (early stage) ramets, we discovered seedlings showing unique genotypes . Monitoring study revealed that a significant number of clonal offspring ramets were observed every year. Ramets did not form inflorescences every year although they could repeatedly flower. By excavating of rhizomes, we found that a ramet performed either clonal growth or flowering in a season and new ramets were capable to produce their offspring in the next season. In a genet, 51.0% of ramets produced flowers and 29.6% generated clonal offspring. Thus, clonal growth generally precedes multiple flowering through life-histories of ramets, indicating that genets carry out sexual reproduction more than clonal growth in C. keiskei. In this population, diverse genets adapting to their habitat conditions have established by sexual reproduction and maintained by clonal growth.
Log in to add this item to your schedule
1 - Hokkaido University, Faculty of Environmental Earth Science, Lab of Ecological Genetics, Sapporo, 060-0810, Japan
plant population biology
Presentation Type: Poster:Posters for Sections
Location: Ball Room & Party Room/SUB
Date: Monday, July 28th, 2008
Time: 12:30 PM