Morphological, cytological and molecular marker analyses of ‘Tapestry’ caladium variants reveal diverse genetic changes and enable association of leaf coloration pattern loci with molecular markers

Abstract

Somaclonal variation and induced mutation are highly valuable sources of genetic variation for genetic improvement and research in horticultural crops; cellular and molecular characterization can greatly facilitate their uses in these areas. In the present study, 20 caladium variants were identified among ‘Tapestry’ plants that were regenerated from leaf cultures treated with or without colchicine. These variants showed changes in leaf main vein color and coloration pattern and were separated into ten groups based on leaf morphological changes. Five variants contained 3.3–9.7% more nuclear DNA than the wildtype and gained one, two or three chromosomes, while four variants contained 3.0–4.8% less nuclear DNA and lost one chromosome. Five, out of 22, simple sequence repeat-based molecular markers detected DNA banding pattern changes in 13 of the 20 variants. Two molecular markers (CaM24 and CaM62) detected DNA banding pattern changes in the same four variants, suggesting that these two markers may be located in the same chromosomal segment. Strong association between leaf characteristics (leaf blotching and main vein color) and molecular banding pattern changes with molecular marker CaM42 were observed in six variants, indicating that CaM42 may be associated with gene loci controlling leaf blotching and leaf main vein color in caladium.