Comparative karyotype and RAPD analysis of four Oxalis L. species

Abstract

Four Oxalis L. species namely O. corymbosa, O. corniculata, O. latifolia, and O. triangularis were investigated cytogenetically and at the molecular level for proper characterization. Different 2n chromosome numbers were found in four species, such as 2n=44 in O. corniculata, 2n=28 in O. latifolia, 2n=30 in O. corymbosa, and 2n=30 in O. triangularis. The diploid chromosome number 2n=30 is the first report for O. triangularis. The four species differed with respect to centromeric formulae, such as 30m in O. corymbosa, 44m in O. corniculata, 24m+4sm in O. latifolia, 26m+4sm in O. triangularis. The four species of Oxalis have distinct CMA- and DAPI banding patterns based on the number, location, intensity, and percentage of GC- and AT-rich repeats. With the help of CMA and DAPI staining, it was possible to mark certain chromosomes specific for each species. Moreover, the four species possess distinct RAPD fingerprinting patterns with species-specific unique marker fragments. RAPD fingerprinting analysis placed O. corymbosa in a different cluster whereas the rest three in another cluster. Therefore, the compilation of the cytological and molecular information will be useful for authentic identification and characterization of the four Oxalis species found in Bangladesh.