IRIDOID GLYCOSIDE AND ALLOZYME VARIATION WITHIN AND AMONG POPULATIONSOF PLANTAGO-RHODOSPERMA DECNE. (PLANTAGINACEAE)

To compare and contrast the inter-and intra-population variation in Pl antago rhodosperma, individuals from four populations in Kansas (Russe ll, Woodston, Stockton A and Stockton B) were sampled. The following f ive characteristics were compared: (1) size of the plants, using area of the largest leaf as an index, (2) number of trichomes on the upper and lower leaf surfaces, (3) iridoid glycoside concentration of leaves and scapes, (4) leaf nitrogen concentration, and (5) allozyme variabi lity. The Russell and Woodston populations were significantly smaller than those from Stockton A and B, and had greater trichome densities o n the upper leaf surface. The Stockton B population had significantly more aucubin in the leaves than the other populations sampled. However , the aucubin concentration in the scapes did not differ among populat ions. The Stockton A and B populations had significantly higher leaf n itrogen concentrations than Russell, but Woodston was not significantl y different from either of the other two. There was little inter-popul ational allozyme variation, although the Russell population showed all ozyme variability among individuals for the enzyme PGI. The allozyme d ata suggest that P. rhodosperma is an allopolyploid. (C) 1997 Elsevier Science Ltd.