Comparative embryology of Bambusa tulda Roxb. and Thyrsostachys siamensis Gamble (Poaceae: Bambuseae)

Bambusa tulda and Thyrsostachys siamensis resemble each other in having an obovate ovary which is hairy and thickened along the apex, a pseudo-crassinucellate ovule with a wide region of attachment, poorly-developed and ephemeral outer integument, an inner integument which fails to grow beyond the nucellus, 'Polygonum' type of embryo sac ontogeny, parallel orientation of embryo sac to the long axis of the ovule, multiple antipodals which retain apical position in the embryo sac even during post-fertilization phase of development, an ephemeral nucellus, relatively small bambusoid embryos, and many-layered and apically thickened pericarp. However, they differ from each other in their gynoecial structure, the extent of the development of the outer integument, organization of megaspore tetrads and development-stage-related behaviour of the inner integument in the fertilized ovules. These taxa also differ from other members of the subfamily Bambusoideae in the structure of the mature ovule, endosperm and pericarp.     

Identification of dry-pinned museum specimens of the sibling species Anopheles gambiae and An.arabiensis (Diptera: Culicidae) using non-radioactively labelled DNA probes

Non-radioactively labelled DNA probes were tested for their ability to identify dried museum specimens of Anopheles gambiae and its sibling species An.arabiensis . The specimens were the progeny of wild-caught females collected in 1991 from villages in western Kenya. Three years later, specimens whose identity was known to the second author were provided 'blind' to the first author for identification with oligonucleotide probes (SH 5 and SH 4 derived from pAngss and pAngsl, respectively) using a simplified squash-blotting protocol for non-radioactive probes. All specimens were successfully identified with whole-body squashes, and the results agreed with previous identifications of parents or siblings based on rDNA-polymerase chain reaction . The amounts of DNA released by squash-blotting were just sufficient for identification by those experienced in the technique, but not for squashes of heads or thoraces alone. An aim of the study was to determine whether squash-blot methods of identification might be useful for establishing the genetic identity of name-bearing type specimens of sibling species held in museum collections.