Molecular mapping of some Arabidopsis thaliana genesdetermining leaf shape and chlorophyll defects.

Six Arabidopsis thaliana mutations were developed in our laboratory and are held at the Nottingham Arabidopsis Stock Centre. Morphological mutations were called cupuliformis, rotundata and involuta. The second group of mutants with chlorophyll defects were chlorominuta, lucida(S) and lucida. The aim of our work was to localise the six mutant alleles on the genetic map of A. thaliana. The level of DNA polymorphism among ecotypes of A. thaliana, S96 and Dijon-G (genetic backgrounds of mutations) vs. Columbia and Landsberg erecta, had to be evaluated to determine suitable parental plants for the crosses. DNA markers, 16 microsatellites and 6 cleaved amplified polymorphic sequences, were used for recombination analysis in F2 populations. The location of the cupuliformis mutation was on the short arm of chromosome 1, the rotundata mutation on the long arm of chromosome 4 and the involuta mutation on the long arm of chromosome 2. The chlorominuta mutation with a chlorophyll defect was located on chromosome 3 and the positions of both lucida and lucida(S) mutations were on chromosome 4. This mapping study simplified gene identification and evaluation of potential allelism with mutants already isolated by previous authors.