CYTOGENETIC ANALYSIS IN POPULATIONS OF ALSTROEMERIA HOOKERI LODD. SSP. HOOKERI (ALSTROEMERIACEAE) FROM BIO-BIO REGION, CHILE

Abstract

Alstroemeria L. (Alstroemeriaceae) is an American genus of monocots, with two distribution centers: Brasil and Chile. In Chile is represented by about 33 species, the most of them in central Chile, an area renowned for its high level of endemism. The "complex" Alstroemeria hookeri is endemic to Chile and distributed from the IV Region of Coquimbo to VIII Region of Bío-Bío. The subspecies hookeri is present in the VII Region of Maule and VIII Region of Bío-Bío. In the VIII Region of Bío-Bío, there are two distribution centers of this subspecies separated by the Coastal Mountain. One center is located in the coastal range of the Region and the other center is located in the Central Valley, specifically on the sandy area of the Central Valley. The cytogenetic analysis of the chromosomes of coastal and eastern populations have shown a remarkable difference in the karyotype, principally in chromosome 3. In the Coastal range populations this chromosome is telocentric while in the Eastern populations is metacentric. Besides, there are differences in chromosomes 4 and 8, in the Coastal ranges populations the chromosome 4 is telocentric and the chromosome 8 is submetacentric while in the Eastern populations both chromosomes are subtelocentric. When indexes of asymmetry of karyotypes are compared among populations (AsK%, TF% and Syi), there are clear differences between populations from both geographical range. The phenetic analysis using cytological data also confirms the separation of the coastal and inland populations within Alstroemeria hookeri ssp. hookeri. It is probably that evolutionary divergence between populations is occurring and the difference in the morphology of chromosome 3 is a morphological evidence for this situation. Preliminary studies of isoenzymes, RAPD, ITS and morphology support this hypothesis.