The efficiency of the water conducting system of tomato roots

2000 ◽  
pp. 371-375 ◽  
Author(s):  
A. Eshel ◽  
Ilona Shick ◽  
Y. Waisel
Keyword(s):  
Conducting System ◽  
Tomato Roots

Allelopathy: a possible mechanism of suppression of plant-parasitic nematodes by entomopathogenic nematodes

Nematology ◽  
1999 ◽  
Vol 1 (7) ◽  
pp. 735-743 ◽  
Author(s):  
Parwinder S. Grewal ◽  
Edwin E. Lewis ◽  
Sudha Venkatachari
Keyword(s):  
Meloidogyne Incognita ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Steinernema Feltiae ◽  
Symbiotic Bacteria ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Tomato Roots ◽  
Xenorhabdus Nematophilus ◽  
Plant Parasitic

Abstract A possible mechanism of suppression of a plant-parasitic nematode Meloidogyne incognita by entomopathogenic nematodes is described. Heat-killed entomopathogenic nematodes Steinernema feltiae and S. riobrave temporarily suppressed penetration of the root-knot nematode M. incognita into tomato roots, but live nematodes had no effect. Infective juvenile M. incognita were repelled from all entomopathogenic nematode treatments that included their symbiotic bacteria. They were repelled by Galleria mellonella cadavers infected with S. carpocapsae, S. feltiae, and S. riobrave and from cell-free culture filtrates of the symbiotic bacteria Xenorhabdus nematophilus, X. bovienii, and Xenorhabdus sp. "R" from the three nematode species, respectively. Cell-free filtrates from all three Xenorhabdus spp. were toxic to M. incognita infective juveniles causing 98-100% mortality at 15% concentration. Cell-free filtrate of Xenorhabdus sp. "R" also reduced the hatch of M. incognita eggs. Application of formulated bacterial cell-free filtrates temporarily suppressed M. incognita penetration into tomato roots in a greenhouse trial. The short-term effects of cell-free bacterial filtrates, namely toxicity and repellency, were almost entirely due to ammonium. These results demonstrate allelopathic interactions between plant-parasitic nematodes, entomopathogenic nematodes and their symbiotic bacteria. The likely role of allelopathy in the suppression of plant-parasitic nematodes by innundative applications of entomopathogenic nematodes is discussed. Allelopathie: Ein moglicher Mechanismus zur Unterdruckung pflanzenparasitarer Nematoden durch insektenpathogene Nematoden - Es wird ein moglicher Mechanismus zur Unterdruckung des pflanzenparasitaren Nematoden Meloidogyne incognita durch insektenpathogene Nematoden beschrieben. Durch Hitze abgetotete insektenpathogene Nematoden Steinernema feltiae und S. riobrave underdruckten das Eindringen des Wurzelgallenalchens M. incognita in Tomatenwurzeln, lebende Nematoden hatten keine Wirkung. Infektionsjuvenile von M. incognita wurden von allen Behandlungen mit insektenpathogenen Nematoden abgestossen, die auch die symbiontischen Bakterien einschlossen. Sie wurden durch die Kadaver von Galleria mellonella abgestossen, die mit S. carpocapsae, S. feltiae und S. riobrave infiziert waren sowie durch zellfreie Kultursubstrate der symbiontischen Bakterien Xenorhabdus nematophilus, X. bovienii und Xenorhabdus sp. "R" aus den drei genannten Nematodenarten. Zellfreie Kultursubstrate von allen drei Xenorhabdus spp. waren giftig fur die Infektionsjuvenilen von M. incognita und verursachten in einer Konzentration von 15% Abtotungsraten von 98-100%. Zellfreie Kultursubstrate von Xenorhabdus sp. "R" vermiderten ausserdem das Schlupfen von M. incognita-Eiern. In einem Gewachshausversuch unterdruckten formulierte zellfreie Bakterienfiltrate vorubergehend das Eindringen von M. incognita in Tomatenwurzeln. Die Kurzzeitwirkungen von zellfreien Bakterien filtraten, namentlich Giftigkeit und Abstossung, waren nahezu ganz bedingt durch Ammoniak. Diese Ergebnisse zeigen das Vorhandensein von allelopathischen Wechselwirkungen zwischen pflanzenparasitaren Nematoden, insektenpathogenen Nematoden und deren symbiontischen Bakterien. Die wahrscheinliche Rolle von Allelopathie bei der Unterdruckung pflanzenparasitarer Nematoden durch eine Massenanwendung insektenpathogener Nematoden wird diskutiert.

scholarly journals Wenckebach phenomenon occurring in the distal conducting system in a young adult.

Heart ◽  
1976 ◽  
Vol 38 (2) ◽  
pp. 204-206 ◽  
Author(s):  
R Gray ◽  
V S Kaushik ◽  
W J Mandel
Keyword(s):  
Young Adult ◽  
Conducting System ◽  
Wenckebach Phenomenon

The systemic nature of the sunflower disease caused by Diaporthe helianthi

1991 ◽  
Vol 69 (7) ◽  
pp. 1552-1556 ◽  
Author(s):  
M. Muntanola-Cvetković ◽  
Jelena Vukojević ◽  
M. Mihaljčević
Keyword(s):  
Plant Diseases ◽  
Leaf Axil ◽  
Plant Tissues ◽  
Conducting System ◽  
Intercellular Spaces ◽  
Histological Studies ◽  
Leaf Petiole ◽  
Diaporthe Helianthi ◽  
Xylem Elements ◽  
Systemic Nature

The systemic nature of the disease of sunflower plants caused by Diaporthe helianthi, the leaf–petiole–stem route of the host invasion by the fungus, and the plant tissues that were successively affected were demonstrated through histological studies. After penetration into the host, the infection hyphae invade the intercellular spaces and terminal veinlets of the lamina and spread toward larger branches of the conducting system, the midrib, and the petiole. Xylem elements are invaded but are affected less by the fungus attack than the phloem and the parenchyma tissues, which disintegrate completely. Hyphae spread through the leaf axil to the tissues of the stem cortex, where pycnidia of the Phomopsis anamorph are initiated from internal masses of mycelium. Key words: systemic plant diseases, sunflower diseases, Diaporthe helianthi, Phomopsis helianthi.

Effect of boron on soluble protein and sugar contents of tomato roots

1985 ◽  
Vol 88 (1) ◽  
pp. 149-151 ◽  
Author(s):  
R. M. Esteban ◽  
J. G. Collado ◽  
F. J. Lopez Andreu ◽  
M. Fernandez Herrera
Keyword(s):  
Soluble Protein ◽  
Tomato Roots

scholarly journals The microcirculation and its measurement in sepsis

2016 ◽  
Vol 18 (3) ◽  
pp. 221-227 ◽  
Author(s):  
Matthew Charlton ◽  
Mark Sims ◽  
Tim Coats ◽  
Jonathan P Thompson
Keyword(s):  
Disease Severity ◽  
Clinical Use ◽  
Conducting System ◽  
Icu Patients ◽  
Microcirculatory Dysfunction ◽  
Microcirculatory Function

The microcirculation describes the smallest elements of the cardiovascular conducting system and is pivotal in the maintenance of homeostasis. Microcirculatory dysfunction is present early in the pathophysiology of sepsis, with the extent of microcirculatory derangement relating to disease severity and prognosis in ICU patients. However, at present microcirculatory function is not routinely monitored at the bedside. This article describes the pathophysiology of microcirculatory derangements in sepsis, methods of its measurement and evidence to support their clinical use.

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