Bulked AFLP analysis for the assessment of genetic diversity in white clover (Trifolium repens L.)

The use of bulked leaf samples from individual plants for amplified fragmen t length polymorphism (AFLP) analysis was evaluated as a tool for assessmen t of genetic diversity in white clover ( Trifolium repens L.). Bulking of l eaf samples produced slightly simpler AFLP profiles compared to the combine d profiles of individual plants from the same cultivar. Approximately 90% o f bands which were present in individual plants were present in bulked samp les of the same cultivar. The majority of those absent were rare bands, sha red by less than 25% of individual plants. Replicate bulk samples gave almo st identical banding patterns, demonstrating the robustness of the bulked A FLP technique. Cluster analysis of AFLP data derived from individual plants resulted in a phenogram similar to that produced from data derived from bu lked samples of the same plants. AFLP analysis of bulked samples detected s ignificant amounts of genetic variability among 52 cultivars and accessions with genetic similarity values ranging from 0.42 to 0.92. However, cluster analysis of AFLP data only partially reflected the geographic origin of cu ltivars and accessions and was not congruent with cluster analysis based on variation for morphophysiological characters. Bulked AFLP analysis provide s a powerful tool for rapid assessment of genetic variability in white clov er and may also be used for cultivar identification.