The family Lomariopsidaceae (Filicopsida) and its probable ancestors

The family Lomariopsidaceae includes eight genera of tropical ferns– Arthrobotrya, Bolbitis, Egenolfia, Elaphoglossum, Lomagramma, Lomariopsis, Teratophyllum and Thysanosoria. Salient morphological features of the Lomariopsidaceae have been enumerated. Views of various authors postulating evolution of this family from Thelypteroid, Dryopteroid, Polystichoid or Dennstaedtioid stocks are discussed and it is concluded that they do not seem to be the ancestors of the Lomariopsidoid ferns. On the other hand, it appears, on the basis of various characters, that the Tectarioid ferns could possibly be the ancestors of the Lomariopsidaceae.     

Cytoembryology of some Malaysian dipterocarps, with some evidence of apomixis

KAUR, A., JONG, K., SANDS, V. E. & SOEPADMO, E., 1986. Cytoembryology of some Malaysian dipterocarps, with some evidence of apomixis. Embryological and cytological studies on some members of the Dipterocarpaceae were undertaken. Of the dipterocarps investigated 83% were diploids. Two new polyploids were observed, namely Shorea resinosa (2 n = 3x = 21) and Hopea subalata (2 n = 3x = 21). Multiple seedlings were observed in H. subalata, Shorea agami, S. argentifolia, S. ovalis, S. pauciflora and S. resinosa. For the first time embryological studies have conclusively demonstrated reproduction by agamospermy in 5. ovalis and S. agami. Considerable evidence leads to the inference that H. subalata, S. resinosa and 5. macroptera are also agamosperms. Each of these produces multiple seedlings. Of these apomictic species three are polyploids, namely S. ovalis (2 n = 4x = 28), H. subalata (2 n = 3x = 21) and S. resinosa (2 n = 3x = 21), whereas S. agami (2 n = 14) and S. macroptera (2 n = 14) are diploids.     

Counting the spots: a molecular and morphological phylogeny of the spotted darner Boyeria (Odonata: Anisoptera: Aeshnidae) with an emphasis on European taxa

Boyeria irene and Boyeria cretensis are species of spotted dragonflies belonging to the ‘darner’ family, Aeshnidae. In 1991, Peters classified Boyeria from Crete as B. cretensis, based on adult morphological characters. In this study, we used molecular evidence to determine if indeed B. irene and B. cretensis are different species. DNA was sequenced from samples of B. irene (from France, Switzerland, Tunisia, Spain and Italy) and B. cretensis (from Crete). These species were recovered as two different clades with strong support. We conclude that B. irene and B. cretensis are different species, with evidence based on molecular and morphological differences. In addition, we present the first phylogenetic hypothesis for Boyeria for which we have sequenced all but three species. Lastly, we discuss different scenarios that may have led to the present‐day distribution and speciation patterns of Mediterranean Boyeria.     

The Effect of Water Activity and the aw Controlling Solute on Spore Germination of Bacillus stearothermophilus

The germination of spores of Bacillus stearothermophilus was studied in nutrient broth in relation to the water activity ( a _w) of the medium, the nature of the a _w controlling solutes glycerol, sucrose, KCl, and NaCl, and temperature. Quantitation of germination was based on the change of the phase-bright spore to phase-dark. Activation of spores was by exposure to 100°C/10 min in a medium of the same composition as that used for germination.
Of the four solutes used, sucrose proved most inhibitory to germination, especially in the upper part of the temperature range 38-75°C, glycerol was the most favourable whereas KCl and NaCl, whose effect was almost identical, occupied an intermediate place. The glycerol effect became more pronounced as the a _w of the medium decreased towards 0.960, becoming inhibitory thereafter.
The solute effect on spore germination followed a pattern that related to the class of solute, i.e. electrolyte or non-electrolyte, and its cell penetration characteristics.
Solute penetration during heat activation and germination was considered as the major germination factor and was associated with the osmoregulation mechanism within the spore proposed recently as the basis of spore dormancy and resistance.