Drought tolerance and AFLP-based genetic diversity in purslane (Portulaca oleracea L.)

Drought stress is an environmental factor that causes severe yield loss in agriculture. Identifying new genetic resources is key to improving crop drought tolerance. Purslane (Portulaca spp.) is a xerophyte that grows in extreme drought conditions worldwide. Here, we report genetic variation in drought tolerant phenotypes, and AFLP-based genetic diversity among purslane accessions collected from geographically diverse regions. Variations among different purslane accessions occurred at seed germination, seedling and adult stages with Tokombiya identified as the most drought tolerant accession at adult stage. Genetic diversity among purslane accessions was evaluated by AFLP fingerprinting. Using the average genetic similarity as cut-off value, four distinct groups were classified by UPGMA-cluster analysis, and Tokombiya was found to be distinct from all other purslane accessions. Together, these results suggest that significant genetic variations exist among purslane accessions and Tokombiya is a unique accession with strong drought tolerance. Further examination of this accession may benefit efforts to improve crop tolerance to drought stress.