Descripción: Variation in genome size of 24 populations belonging to 11 NW Patagonian species of Berberis was analysed as a function of the environment and geographical location. The variation showed three levels of discontinuity, two of which corresponded to diploid species (2n = 28) while the third corresponded to polyploid species (2n = 56). Diploids with DNA content ranging from 1.463 pg to 1.857 pg included Berberis cabrerae, B. chillanensis, B. montana, B. serrato-dentata and B. bidentata. Diploids with DNA content ranging from 2.875 pg to 3.806 pg included B. linearifolia, B. darwinii, B. parodii and B. empetrifolia. The genome size of the polyploid species B. buxifolia and B. heterophylla ranged from 5.809 pg to 6.844 pg. Principal component analysis (PCA) was applied to represent the variability of environmental conditions. The eigenvectors of the principal component axes showed that PCl discriminates the populations according to rainfall, types of vegetation and geomorphology; altitude and latitude, on the other hand, contribute to PC2 and PC3, respectively. From these results it is concluded: (1) that diploids with lower DNA content grow in high-elevation sites having greater rainfall but lower water availability; (2) diploids with higher DNA content are associated with half-elevation forests where the vegetative period is longer, the water availability is greater and the temperatures are higher; and (3) the distribution pattern of polyploids is considerably wider than that of diploids, which are geographically and ecologically restricted to forest areas. These results suggest that the C-value plays an important role in the ability of the species to adapt to different growing conditions. (C) 2000 Annals of Botany Company.

Descripción: Sequence analysis of the internal transcribed spacer (ITS) of the 18S(ITS1)-5.8S-26S(ITS2) rDNA region was performed in order to analyse the phylogenetic relationships between 13 Patagonian species of the genus Berberis (Berberidaceae). The divergence values between the pairwise sequence in the studied Patagonian species were in the range 2.9-22.9%. The lengths of the ITS1 and ITS2 sequences were in the range 227-231 bp and 220-224 bp, respectively, and the 5.8S sequence was 159 bp throughout all species. B. microphylla sensu Landrum does not appear to be monophyletic based on current sampling. Indeed, we suggest that B. microphylla should be distinguished from B. buxifolia, B. parodii, and B. heterophylla. ITS sequences, together with data obtained from morphological, biochemical, amplified fragment length polymorphism, and cytological characterizations, support the existence of diploid and polyploid hybrid speciation in the genus. © 2007 The Linnean Society of London.

Descripción: Phenetic relationships among species of Berberis (Berberidaceae) from NW Patagonia. Darwiniana 35: 115-129. Phenetic relationships among 11 species belonging to the genus Berberis from 46 populations of NW Patagonia Argentina, were studied using numerical techniques. The species are B. bidentata Lechl., B. buxifolia Lam., B. cabrerae Job, B. chillanensis Sprag. ex Sandwith, B. darwinii Hook., B. empetrifolia Lam., B. heterophylla Juss., B. linearifolia Phil., B. montana Gay, B. parodii Job and B. serrato-dentata Lechl. Fifty four morphological characters were defined (24 vegetative and 30 reproductive). Forty six populations (with a total of 288 individuals) were analyzed. Two main groups were distinguished from the phenogram. One consists of the populations of 10 spiny species; the other one is only formed by populations of B. serrato-dentata (without - or rarely / with scarce little weak - spines). Numerical analysis allowed to differentiate the species studied and each of the populations within a same species. This may be related to microambiental agents conditioning the phenotype. The results here obtained agree fairly well with the interespecific relationships previously published in the genus Berberis.