AFLP analysis of somaclonal variation in Arabidopsis thaliana regenerated plants

AFLP analysis was performed in order to assess DNA variation among Arabidopsis thaliana plants regenerated by organogenesis from roots. Fifty-one regenerated plants were subjected to AFLP analysis using 12 primer combinations. The plants were obtained from root explants excised from five different seedlings. From the studied plants, 66.6% showed at least one variation when compared against the regenerated plants obtained from the same explant, and the number of mutations per plant ranged from one up to 18. However, the average proportion of shared AFLP fragments was higher than 99.4% among the regenerated plants as the variation found was due mainly to unique changes in single plants (singletons). The distribution of variation among the regenerated plants was uneven and only three regenerated plants accumulated 40% of the variations observed. Three AFLP markers out of the total 778 detected markers were polymorphic for several plants obtained from different calli. These markers may represent hypervariable regions of Arabidopsis genome. Values of nucleotide diversity estimated for each group of regenerated plants were from two to three orders of magnitude smaller than natural variation described for ecotypes of A. thaliana. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.