Evolution of alkaloid biosynthesis in the genus Narcissus

In an attempt to reveal the relationships between alkaloid biosynthesis and phylogeny, we investigated by GC–MS the alkaloid patterns of 22 species and 3 hybrids (from 45 locations) from seven main sections of the genus Narcissus (Amaryllidaceae). The results indicate that the first alkaloids to evolve in the genus Narcissus were of the lycorine- and homolycorine-type. The alkaloid pattern of the Nevadensis section supports its recent separation from the Pseudonarcissus section. The plants of Narcissus pallidulus (Ganymedes section) show a predominance of Sceletium-type compounds, which are quite rare in the Amaryllidaceae family. Two successful evolutionary strategies involving alkaloid biosynthesis and leading to an expansion in taxa and occupied area were determined. Firstly, a diversification of alkaloid patterns and a high alkaloid concentration in the organs of the large Narcissus species (in the Pseudonarcissus section) resulted in an improved chemical defence in diverse habitats. Secondly, both plant size and alkaloid biosynthesis were reduced (in the Bulbocodium and Apodanthi sections) relegated to dry pastures and rocky places.

Implantação de planos de fogo controlado na gestão dos recursos alimentares para cavalos da raça Garrana em Valença

Dissertação apresentada à Escola Superior Agrária do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Tecnologias e Sustentabilidade dos Sistema Florestais.

Granulometry, calcium carbonate content and radiocarbon ages of soil profiles obtained in Quinghai Province, northeast Tibet

Colluvial deposits consisting of silts and loams were detected in several climatologically different areas of NE Tibet (3200-3700 m a.s.l.). Layering, distinct organic content and low content of coarse matter as well as location in the relief revealed an origin from low-energy slope erosion (hillwash). Underlying and intercalated paleosols were classified as Chernozems, Phaeozems, Regosols and Fluvisols. Fifteen radiocarbon datings predominant on charcoal from both colluvial layers and paleosols yielded ages between 8988 ± 66 and 3512 ± 56 uncal BP. Natural or anthropogenic factors could have been the triggers of the erosional processes derived. It remains unclear which reason was mainly responsible, due to controversial paleoclimatic and geomorphic records as well as insufficient archaeological knowledge from this region. Determinations of charcoal and fossil wood revealed the Holocene occurrence of tree species (spruce, juniper) for areas which nowadays have no trees or only few forest islands. Thus large areas of NE Tibet which are at present steppes and alpine pastures were forested in the past.

The hawkweeds, or paintbrushes /

"Contribution from the Bureau of Plant Industry (Office of Forage-Crop Investigations)."

Les pasturages, les prairies naturelles, et ls herbages.

Mode of access: Internet.

Essays on miscellaneous subjects /

I. Observations of the nature and advantages of statistical inquiries -- II. Observations on the means of enabling a cottager to keep a cow --III. Hints as to the advantages of old pastures -- IV. Hints regarding cattle -- V. On the improvement of British wool -- VI. Address to the Board of Agriculture -- VII. Substance of a speech in a committee of the whole House --VIII. Hints regarding certain measures calculated to improve an extensive property -- IX. Account of the origin of the Board of Agriculture -- X. Proposals for establishing by subscription a new institution to be called the Plough -- XI. Letter to the proprietor of an extensive property -- XII. On longevity.

Beitekultur.

Mode of access: Internet.

Approved practices in pasture management,

Mode of access: Internet.

Die dauerweiden, bedeutung, anlage und betrieb derselben unter bedsonderer berücksichtigung intensiver wirtschaftverhältnisse,

Mode of access: Internet.

Byways in Bookland; confessions and digressions,

Printed in Great Britain.

Non-federal grazing lands in the United States.

"October 1996"--P. [22].

Permanent pasture compared with a 5-year crop-and-pasture rotation for dairy cattle feed /

Caption title.

A Pasture handbook /

Includes index.

A Pasture handbook /

Caption title.

A Pasture handbook /

Includes index.