Dynamics of the growth unit of substrate mycelium in streptomycete colonies

BIOPHYSICS ◽  
2007 ◽  
Vol 52 (3) ◽  
pp. 350-353
Author(s):  
A. P. Saveliev
2000 ◽  
Vol 78 (12) ◽  
pp. 1531-1544 ◽  
Author(s):  
Eric Nicolini ◽  
Daniel Barthélémy ◽  
Patrick Heuret

The growth and branching patterns of the main axis of 6-year-old sessile oak, growing in a natural regeneration in the north of France, were analysed each year retrospectively according to three increasing canopy density conditions: large gap, small gap, and dense canopy. Increasing gap size is associated with an increase in the total height, basal diameter, branching probability, and global polycyclism rate of the trees. At the growth unit or annual shoot level, from dense canopy to large gaps these botanical entities also show an increase in their total length, number of nodes, polycyclism, and branching rate as well as mean number of branches and mean internode length. A discussion of our results revealed some endogenous features of growth and branching patterns in young sessile oak trees. It is also shown that increasing canopy density generally tends to reduce the expression of the endogenous architectural sequence of differentiation of young sessile oak trees. Young trees growing below dense canopy thus seem to be "delayed" in their sequence of differentiation and appear to be in a "waiting" status, whereas young trees growing in large gaps exhibit an architecture very similar to trees growing in nurseries under nonlimiting growth conditions.Key words: architecture, Quercus petraea, growth, morphology, canopy density.


1996 ◽  
Vol 45 (12) ◽  
pp. 2082
Author(s):  
YUAN RU-LIN ◽  
SHI ER-WEI ◽  
XIA CHANG-TAI ◽  
WANG BU-GUO ◽  
ZHONG WEI-ZHOU

1996 ◽  
Vol 121 (1) ◽  
pp. 115-122 ◽  
Author(s):  
K.I. Theron ◽  
G. Jacobs

Large Nerine bowdenii bulbs (>14 cm in circumference) were exposed to low ligbt intensities for different periods during two successive growing seasons. The flowering percentage and number of florets in the current season's inflorescence were recorded at anthesis. Small and large bulbs were subjected to continual defoliation starting at different times during the growing season. Bulbs were dissected at planting (26 Sept. 1992) and on 12 Jan. 1993 (nondefoliated control bulbs) to determine growth and developmental stage. At anthesis, inflorescences were harvested and the florets per inflorescence were counted. After anthesis in the fall, all bulbs were dissected and the following variables recorded: 1) percentage flowering, quiescence, or abortion of the current season's inflorescence; 2) developmental stage of quiescent inflorescences; 3) number of florets in the outermost inflorescence; 4) developmental stage of the innermost inflorescence; 5) number of leaves or leaf bases in each growth unit; 6) number of daughter bulbs; and 7) dry weight of new leaf bases. There were three reasons for nonflowering of the bulbs, viz., failure to initiate an inflorescence, inflorescences remaining quiescent, and inflorescence abortion. Individual florets that had not reached stage “Late G” (gynoecium elongated, carpels fused) at the start of rapid inflorescence elongation aborted. The more florets that aborted, the greater the probability that the entire inflorescence aborted. The inflorescence was more vulnerable to stress during the first half of the growing season due to its relatively weak position in the hierarchy of sinks within the bulb.


2011 ◽  
Vol 61 (12) ◽  
pp. 2811-2815 ◽  
Author(s):  
Honghui Zhu ◽  
Shumei Jiang ◽  
Qing Yao ◽  
Yonghong Wang ◽  
Meibiao Chen ◽  
...  

An actinomycete, designated strain GIMN4.003T, was isolated from seawater collected in Sanya, China. It produced white aerial mycelium and yellow substrate mycelium on Gause’s synthetic agar medium no. 1. The substrate mycelium colour was not sensitive to pH. Scanning electron microscopy observations revealed that GIMN4.003T produced straight to flexuous spore chains of rough to warty spores. ll-Diaminopimelic acid was present in the cell-wall hydrolysate. Based on chemotaxonomy and morphological features, strain GIMN4.003T was identified as a member of the genus Streptomyces. Melanin was not produced. No antimicrobial activity was detected against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Penicillium citrinum or Candida albicans. Analysis of the 16S rRNA gene sequence revealed that the highest sequence similarity was to Streptomyces radiopugnans R97T (99.0 %). However, DNA relatedness between GIMN4.003T and S. radiopugnans DSM 41901T was low (41.24±1.47 %). Furthermore, the morphological, physiological and biochemical characteristics of strain GIMN4.003T were different from those of S. radiopugnans DSM 41901T and the type strains of other closely related Streptomyces species. On the basis of its physiological and molecular properties, it is evident that strain GIMN4.003T ( = CCTCCM 208215T  = NRRL B-24801T) represents the type strain of a novel species within the genus Streptomyces, for which the name Streptomyces fenghuangensis sp. nov. is proposed.


1992 ◽  
Vol 62 (3) ◽  
pp. 353-358
Author(s):  
Yu. K. Lingart ◽  
S. V. Mukhin ◽  
A. S. Sapozhnikov ◽  
N. A. Tikhonova

Chemosphere ◽  
2018 ◽  
Vol 210 ◽  
pp. 279-286 ◽  
Author(s):  
Pavel Coufalík ◽  
Richard Čmelík ◽  
Kamil Křůmal ◽  
Lukáš Čapka ◽  
Pavel Mikuška

1985 ◽  
Vol 31 (11) ◽  
pp. 1070-1070
Author(s):  
Carmen Méndez ◽  
Alfredo F. Brāna ◽  
Manuel B. Manzanal ◽  
Carlos Hardisson

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