Cytological and biochemical characterization of Alstroemeria, Leontochir and Bomarea.

摘要

Isozyme characterization and cytological analysis were used to characterize and identify species and cultivars of Alstroemeria, Leontochir and Bomarea. Twenty four species, hybrids and color variants of Alstroemeria, two plants of Leontochir ovallei and one plant of Bomarea species, as well as 23 cultivars were available for isozyme characterization. Nine species of Alstroemeria, two Leontochir ovallei, one Bomarea species and 22 Alstroemeria cultivars were investigated to determine their karyotypes and the Giemsa banding patterns of their chromosomes.;Seven isozyme systems were identified which exhibited a high level of polymorphism among the species. A single technique was developed for the extraction of all of these enzymes. The enzyme systems investigated were phosphogluco-mutase, phosphogluco-isomerase, 6-phosphogluconate dehydrogenase, aspartate amino transferase, malic enzyme, esterase and leucine amino peptidase.;It was found that between 11 and 18 of the species and hybrids could be identified uniquely for each of the first six enzyme systems. The final system, leucine amino peptidase was tested on only 11 species and hybrids and 9 different patterns were identified. Using only 3 of the seven enzyme systems it was possible to uniquely identify all of the species and hybrids investigated.;When the 23 cultivars were analyzed, using the first six enzymes, a high level of variability was evident. This was expected due to the polyploid nature of most of the cultivars. The highest level of variability was found for esterase with which 20 of the 23 cultivars exhibited unique banding patterns. All of the cultivars could be uniquely characterized using a combination of only two of the six enzymes.;Very little is known about the parentage of most of the cultivars. Comparison of the banding patterns of the cultivars and the species allowed the identification of the possible parents of each of the cultivars studied.;Using both karyotype analysis and Giemsa banding it was possible to identify individual chromosomes within each species. The identification of a particular species could then be described in terms of the characteristics of each chromosome pair within the complement. The karyotype of all three genera was quite similar, particularly the distribution of acrocentric and the smaller metacentric and submetacentric chromosomes. However, Alstroemeria had 2n = 2x = 16 chromosomes, whereas Leontochir and Bomarea had 2n = 2x = 18 chromosomes. Characterization and identification of cultivars was also possible using these techniques. Each cultivar studied had a unique complement of chromosomes which clearly identified the cultivar.;Using these two approaches it is possible to uniquely identify the species and cultivars of all three genera. This information may now be used to determine the probable parentage of the cultivars. The present study also provides an approach which can be used to further the understanding of the relationships between these three genera. When more species have been studied and their unique characteristics revealed, it will be possible to use this information to clarify the identity of the putative parents of the European cultivars.