Molecular phylogenetic analysis of Podostemaceae: implications for taxonomy of major groups

The river‐weed family Podostemaceae (c. 300 species in c. 54 genera) shows a number of morphological innovations to be adapted to its unusual aquatic habitat, and its unique or rare bauplan features have been reflected in the traditional (i.e. non‐molecular) classification recognizing numerous monotypic or oligospecific genera. The infrasubfamilial relationships of many genera remained unclear. The present study used molecular phylogenetic analysis of matK sequences for 657 samples (c. 132 species/c. 43 genera). The family was traditionally divided into three subfamilies (Podostemoideae, Tristichoideae and Weddellinoideae). American Podostemoideae were shown to be polyphyletic and divided into four clades, i.e. Ceratolacis, Diamantina, Podostemum and all other genera. Among the podostemoid clades, Diamantina was the first branching clade and a clade comprising Mourera and the Apinagia subclade was then sister to the remainder of the New World and Old World Podostemoideae with low statistic supports. The Old World Podostemoideae comprised four monophyletic clades, i.e. two African clades, one Madagascan clade and one Asian clade, although the relationships among these clades and American Ceratolacis and Podostemum were poorly resolved. African Podostemoideae were polyphyletic, with Saxicolella pro parte being weakly supported as sister to the remaining Old World Podostemoideae plus Ceratolacis and Podostemum. In contrast to the American and African clades, monophyly of four Asian subclades was well supported. Plants of Tristicha (Tristichoideae) and of Weddellina (Weddellinoideae), which are currently treated as monospecific, had great matK differentiation equivalent to at least interspecific variation. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169 , 461–492.     

Floral Pigmentation in Gibberellin-treated Tulips

Pigmentation in the perianths of GA₃-trcated tulips was studiedspectrophotometrically and colorimetrically. Anthocyanin pigmentationin the perianth was enhanced by treatment with 300 and 400 ppmGA, I ml per plant, in the form of drops applied to the apicalmeristem still enclosed by whorled undeveloped foliage. Rapidanthocyanin pigmentation accompanied by the disappearance ofchlorophylls in the perianth commenced in the following order:perianth of plants receiving 2, 5, 8 °C treatments for onemonth each with two GA applications followed by those receiving2, 5, 8 °C with one GA application and finally those receiving2, 5, 8 °C without GA. By treating with GA dissolved inmethanol, anthocyanins appeared on the perianth tip first. Inthe case of GA in ethanol application, however, the anthocyaninpigmentation occurred from the upper half of the perianth.