Morphometric analyses of capsule and seed traits in Scandinavian Papaver radicatum (Papaveraceae) in relation to the bicentric distribution pattern

• Published in: Nordic Journal of Botany
• Main Author: Selin, Eva
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1998
• Subjects: Plant Science; Ecology, Evolution, Behavior and Systematics; Norway; Northern Norway; Papaver radicatum
• Online Access: http://dx.doi.org/10.1111/j.1756-1051.1998.tb01551.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1756-1051.1998.tb01551.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1756-1051.1998.tb01551.x

The bicentric distribution pattern of certain plant species in the southern and northern Scandinavian mountains has been explained in different ways. Either by refugial survival, by late‐glacial immigration to the first deglaciated areas in southern and northern Norway or by a successive fragmentation of wide‐distributed populations during post‐glacial time — or by present‐day ecological factors. Even if the bicentric distribution pattern is at least partly explained by present‐day ecological conditions, the question about the origin of the bicentric distribution still remains. One way to tackle this problem, is to investigate the morphometric and/or the genetic differentiation between isolated populations of ‘bicentric’ species and its impact on the explanation of the disjunct pattern. The overall morphometric differentiation pattern in seeds and capsules was investigated in populations of Papaver radicatum , a perennial herb with a bicentric distribution in the Scandinavian mountain range. Canonical variates analysis of capsules separates the populations into two groups in accordance with their geographic origin, i.e. the regions of southern and northern Scandinavia. The differentiation pattern indicates a two‐step development of the present‐day distribution: first separation of the southern and northern Scandinavian occurences of older origin, then separation between populations within each region. The results from canonical variates analysis of seeds shows a weaker variation pattern with a tendency of overlapping inter‐region populations. The most northerly situated populations from the southern region are grouped with populations from the northern region. The pattern of differentiation in capsules may be interpretated in terms of refugial survival or late‐glacial immigration. However, the variation pattern in seeds rather points to a scenario where a widespread occurrence that previously ranged from southern to northern Scandinavia was successively fragmented, which makes a postglacial development of the ...