Studies on upper timberline: morphology and anatomy of Norway spruce (Picea abies) and stone pine (Pinus cembra) needles from various habitat conditions

1976 ◽  
Vol 54 (14) ◽  
pp. 1622-1632 ◽  
Author(s):  
M. N. Baig ◽  
W. Tranquillini
Keyword(s):  
Picea Abies ◽  
Habitat Conditions ◽  
Pinus Cembra ◽  
Valley Bottom ◽  
Cuticle Formation ◽  
Alpine Timberline ◽  
Upper Timberline ◽  
Wind Exposure ◽  
Cuticle Thickness

The importance of the anatomy of the needles of coniferous trees in determining alpine timberline was studied in the Austrian Alps. Samples of 1- and 2-year-old needles of Picea abies (L.) Karst. and Pinus cembra L. were made from wind-exposed and wind-protected timberline (2140 m above sea level (a.s.l.)), and from the kampfzone (2040 m a.s.l.), forestline (1940 m a.s.l.), and valley bottom (1000 m a.s.l.). The samples were measured for number of needles per centimetre twig, twig length, needle length, cuticle thickness, thickness of epidermis and hypodermis, and depth of stomatal crater. There is a decrease in cuticle thickness with increasing altitude and with increasing wind exposure at timberline, and this is correlated with increased transpiration. The role of inadequate cuticle formation in desiccation damage and mortality of the needles is a significant factor in the control of upper timberline.

scholarly journals On iron flagellates

1946 ◽  
Vol 232 (588) ◽  
pp. 311-342 ◽  
Keyword(s):  
Organic Substances ◽  
Habitat Conditions ◽  
Liquid Media ◽  
Brown Colour ◽  
Fe And Mn ◽  
Iron Deposits ◽  
Manganese Compounds ◽  
Small Content ◽  
Iron And Manganese

The physiology and morphology of iron- and manganese-depositing flagellates are investigated by means of cultural experiments, with special reference to Anthophysa vegetans Stein, Siderodendron manganiferum n.gen., n.sp., Siphomonas Fritschii n.gen., n.sp. and Bikosoeca ( Poteriodendron ) petiolata (Stein) n.comb. Anthophysa multiplies in various liquid media containing small amounts of organic substances, hay decoction being specially favourable. Still better results are achieved with soil-water cultures, which afford the only successful cultures of Siderodendron and Siphomonas , while Bikosoeca also grows well in hay infusions. Addition of Fe" and Mn" is essential. The brown colour of biological iron deposits is shown to be due to admixture of manganese compounds, while mere ferric precipitates are in microscopical amounts almost colourless. Anthophysa and Siderodendron deposit more manganese than iron, so that their stalks appear brown, while those of Siphomonas are generally light brown. The envelopes of Bikosoeca are almost entirely composed of ferric compounds and appear colourless or faintly yellowish. All four organisms exhibit various modifications according to the habitat conditions. The formation of stalks and envelopes respectively depends on the availability of the relevant metals in the form of lower oxides, but the organisms here described can also exist without producing these structures. The oxidation of ferrous and manganese compounds is catalysed by the cells of these flagellates, although the role of this process in the cellular metabolism is not known. Nutrition is holozoic, chiefly by ingestion of bacteria. Like other holozoic flagellates these organisms cannot exist in the presence of an abundant bacterial vegetation owing to the resulting lack of oxygen. They thrive in quiet, well-aerated waters, with a small content of organic substances, above zones in which Fe and Mn compounds are reduced and from which ferrous and manganous compounds diffuse to the overlying oxidation zone, where these flagellates deposit Fe"' and Mn'" in a morphologically defined form. ‘Iron’ flagellates generally live in association and competition with iron bacteria of the Leptothrix group, the removal of which produces much better growth. A description of the relevant flagellates and of their appearance under various conditions, as well as diagnoses of Siderodendron and Siphomonas , are given.

Development of fruit cuticle in cherry tomato (Solanum lycopersicum)

2008 ◽  
Vol 35 (5) ◽  
pp. 403 ◽  
Author(s):  
Eva Domínguez ◽  
Gloria López-Casado ◽  
Jesús Cuartero ◽  
Antonio Heredia
Keyword(s):  
Fruit Development ◽  
Tomato Fruit ◽  
Significant Loss ◽  
Fruit Growth ◽  
Epidermal Differentiation ◽  
Cherry Tomato ◽  
Cellulose Material ◽  
Cuticle Formation ◽  
Fruit Development And Ripening ◽  
Cuticle Thickness

The cuticle of a plant plays an important role in many physiological events of fruit development and ripening. Despite this, little is known about cuticle formation and development. We include a detailed morphological study at the microscopic level of cuticle during fruit growth and ripening using tomato as a fruit model. In addition, a study of the differences in cuticle thickness and composition during development is included. The four genotypes studied in this work showed a similar timing of the main morphological events: initiation of epidermal differentiation, changes in the distribution of the lipid, pectin and cellulose material within the cuticle, appearance of pegs, beginning of cuticle invaginations, maximum thickness and loss of polysaccharidic material. Fruit growth, measured by fruit diameter, showed a positive correlation with the increase of cuticle thickness and the amount of cuticle and their cutin and polysaccharide components per fruit unit during development. By contrast, cuticle waxes showed a different behaviour. Two important characteristics of cuticle growth were observed during tomato fruit development. First, the amount of cuticle per surface area reached its maximum in the first 15 days after anthesis and remained more or less constant until ripening. Second, there was a significant loss of polysaccharidic material from the beginning of ripening (breaker stage) to full red ripe.

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