GENOME SIZE VARIATION AND C-BAND POLYMORPHISM IN ALSTROEMERIA-AUREA, ALSTROEMERIA-LIGTU AND ALSTROEMERIA-MAGNIFICA (ALSTROEMERIACEAE)

Among a total of 43 accessions of Alstroemeria aurea, A. ligtu and A. magnifica nuclear DNA amounts (2C-values) showed significant intraspec ific variation, 1.09, 1.21 and 1.15 fold, respectively, when determine d through flow cytometric measurements of fluorescence of propidium io dide (PI) stained nuclei. After staining with another fluorochrome, 4' ,6-diamidino-2-phenylindole (DAPI), an intraspecific variation of 1.10 , 1.11 and 1.12 fold, respectively, was found. C-band polymorphisms we re present among and within the accessions of all three species. In so me cases only very small differences in C-banding pattern were observe d. In other cases, however, differences were more prominent. Besides C -band polymorphism, there were also instances of chromosome length pol ymorphism, which concerned the total chromosome complement or single c hromosomes. The variation in nuclear DNA amount in A. aurea and A. lig tu was more or less continuous, except for one accession of A. ligtu s ubsp. simsii. Artificial selection and possibly introgression of chrom osomes from other species may have moulded the karyotypes of some of t he accessions of A. aurea, a species that has been under cultivation f or more than 160 years. The variation as observed in A. magnifica subs p. magnifica was discontinuous and could be due to a broad species con cept.