Isolation and characterization of fast-neutron induced mutants with abnormal leaf morphology in Arabidopsis thaliana

In order to identify novel genes involved in the morphogenesis of plant leaves and to obtain new null alleles of previously identified genes, we screened 23,445 M-2 Arabidopsis thaliana individuals, the progeny of 2,931 M-1 Landsberg erecta parentals exposed to fast neutron bombardment. We isolated 901 M-2 putative mutants, most of which showed unstable phenotypes that were lost after one or two generations of selfing. We subjected to genetic analysis 25 mutants, whose phenotypes were transmitted with complete penetrance and small variations in expressivity, which fell into 9 complementation groups. Some of them corresponded to genes previously undescribed at the mutational level, their mutant alleles causing a dentate leaf marginal configuration and reduced number of mesophyl cells, some displayed bilaterally asymmetric leaves, and others had either involute or small leaves. Novel alleles of previously described genes, such as CLF and AS1, were also obtained.