scholarly journals Production of Didymella rabiei Pseudothecia and Dispersal of Ascospores in a Mediterranean Climate

2005 ◽  
Vol 95 (11) ◽  
pp. 1279-1286 ◽  
Author(s):  
E. Gamliel-Atinsky ◽  
D. Shtienberg ◽  
H. Vintal ◽  
Y. Nitzni ◽  
A. Dinoor

Temperature and wetness conditions required for development and maturation of Didymella rabiei pseudothecia were determined in a series of experiments conducted in controlled-environmental conditions. Initial stages of pseudothecium formation occurred at temperatures ranging from 5 to 15°C. Incubation at low temperatures was essential for subsequent pseudothecium maturation. This requirement was satisfied for chickpea stem segments incubated at 5 or 10°C for three consecutive weeks or during periods of 3 or 5 days, separated by periods at higher temperatures. Following the low-temperature requirement, subsequent pseudothecium development was independent of temperature in the range tested (5 to 20°C). Wetness was essential for pseudothecium production: pseudothecia formed and matured on stem segments maintained continuously wet but also on those exposed to periods of three or five wet days, separated by dry periods. The dispersal of D. rabiei ascospores was studied using chickpea plants as living traps in the field. Trap plants were infected mainly when exposed during rain but also in rainless periods. Results of this study enabled us to describe the developmental events leading to the production of the teleomorph stage and the dispersal of ascospores by D. rabiei in the Mediterranean climate of Israel.

IAWA Journal ◽  
2004 ◽  
Vol 25 (1) ◽  
pp. 71-77 ◽  
Author(s):  
G.K. Psaras ◽  
I. Sofroniou

Wood from the stems and roots of the malacophyllous Mediterranean drought semi-deciduous species Phlomis fruticosa was studied. The stem is diffuse-porous with narrow vessels. Though narrow vessels impose high conducting resistance, they are less vulnerable to cavitations, thus providing safety during summer drought and winter freezing. The geographical distribution of the plant (up to 1400 m altitude) may be relevant to the occurrence of narrow stem vessels, which provide high resistance to cavitations from low temperatures during winter. Vessel grouping in the stem adds to the safety against cavitations. Root vessels are mostly solitary and have almost double the diameter of stem vessels. Diffuse-porosity, the presence of narrow vessels in stems and the values of vulnerability and mesomorphy indices, are adaptations to the two stresses imposed by the Mediterranean climate, i.e. summer drought and winter cold.


About fifty years ago Professor C. T. R. Wilson began a classical series of experiments (Wilson 1895 to 1933) on the condensation of water vapour in both dust-free and ordinary air. The only reference to ice throughout that work is as follows (Wilson 1897 c , p. 299): ‘It is assumed here that the cloud-particles are actually liquid drops and not ice crystals, in spite of the fact that the condensation begins at temperatures much below the freezing-point and that the temperature when the particles are fully grown is, as we shall see, also slightly below the freezing-point.’ In the present paper experiments are described in which the final temperatures after expansion are much lower. These confirm that down to surprisingly low temperatures only liquid water droplets are formed, but they show that after a threshold low temperature is passed ice particles begin to be formed. These ice particles are not formed by the freezing of water droplets but by the direct sublimation of water vapour to ice crystals, and the process has some essential differences from the condensation of water vapour at higher temperatures. The experiments also indicate that in ordinary outdoor air there are no sublimation nuclei on which the ice crystals form when the air is supersaturated at temperatures between 0 and — 32° C.


Author(s):  
F. H. Louchet ◽  
L. P. Kubin

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.


Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  

Abstract Invar is an Fe-Ni alloy with 36% Ni content that exhibits the lowest expansion of known metals from very low temperatures up to approximately 230 deg C (445 deg F). Invar M93 is a cryogenic Invar with improved weldability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear and bend strength as well as fracture toughness and fatigue. It also includes information on low temperature performance as well as forming and joining. Filing Code: FE-143. Producer or source: Metalimphy Precision Alloys.


Author(s):  
Dean Jacobsen ◽  
Olivier Dangles

Chapter 5 is focused on how organisms cope with the environmental conditions that are a direct result of high altitude. Organisms reveal a number of fascinating ways of dealing with a life at high altitude; for example, avoidance and pigmentation as protection against damaging high levels of ultraviolet radiation, accumulation of antifreeze proteins, and metabolic cold adaptation among species encountering low temperatures with the risk of freezing, oxy-regulatory capacity in animals due to low availability of oxygen, and root uptake from the sediment of inorganic carbon by plants living in waters poor in dissolved carbon dioxide. These and more adaptations are carefully described through a number of examples from famous flagship species in addition to the less well-known ones. Harsh environmental conditions work as an environmental filter that only allows the well-adapted species to slip through to colonize high altitude waters.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3313
Author(s):  
Juan Luis Aguirre ◽  
María Teresa Martín ◽  
Sergio González ◽  
Manuel Peinado

The effects of two types of biochar on corn production in the Mediterranean climate during the growing season were analyzed. The two types of biochar were obtained from pyrolysis of Pinus pinaster. B1 was fully pyrolyzed with 55.90% organic carbon, and B2 was medium pyrolyzed with 23.50% organic carbon. B1 and B2 were supplemented in the soil of 20 plots (1 m2) at a dose of 4 kg/m2. C1 and C2 (10 plots each) served as control plots. The plots were automatically irrigated and fertilizer was not applied. The B1-supplemented plots exhibited a significant 84.58% increase in dry corn production per square meter and a 93.16% increase in corn wet weight (p << 0.001). Corn production was no different between B2-supplemented, C1, and C2 plots (p > 0.01). The weight of cobs from B1-supplemented plots was 62.3%, which was significantly higher than that of cobs from C1 and C2 plots (p < 0.01). The grain weight increased significantly by 23% in B1-supplemented plots (p < 0.01) and there were no differences between B2-supplemented, C1, and C2 plots. At the end of the treatment, the soil of the B1-supplemented plots exhibited increased levels of sulfate, nitrate, magnesium, conductivity, and saturation percentage. Based on these results, the economic sustainability of this application in agriculture was studied at a standard price of €190 per ton of biochar. Amortization of this investment can be achieved in 5.52 years according to this cost. Considering the fertilizer cost savings of 50% and the water cost savings of 25%, the amortization can be achieved in 4.15 years. If the price of biochar could be reduced through the CO2 emission market at €30 per ton of non-emitted CO2, the amortization can be achieved in 2.80 years. Biochar markedly improves corn production in the Mediterranean climate. However, the amortization time must be further reduced, and enhanced production must be guaranteed over the years with long term field trials so that the product is marketable or other high value-added crops must be identified.


2021 ◽  
Author(s):  
Mingming Su ◽  
Yajing Hu ◽  
Ao Yu ◽  
Zhiyao Peng ◽  
Wangtao Long ◽  
...  

Broadband photodetectors fabricated with organic molecules have the advantages of low cost, high flexibility, easy processing and low-temperature requirement. Fullerene molecules, due to the electron acceptor and photoinduced electron transfer...


2014 ◽  
Vol 986-987 ◽  
pp. 80-83
Author(s):  
Xiao Xue Zhang ◽  
Zhen Feng Wang ◽  
Cui Hua Li ◽  
Jian Hong Liu ◽  
Qian Ling Zhang

N-methyl-N-allylpyrrolidinium bis (trifluoromethanesulfonyl) imide (PYR1ATFSI) with substantial supercooling behavior is synthesized to develop low temperature electrolyte for lithium-ion batteries. Additive fluoroethylene carbonate (FEC) in LiTFSI/PYR1ATFSI/EC/PC/EMC is found that it can reduce the freezing point. LiFePO4/Li coin cells with the FEC-PYR1ATFSI electrolyte exhibit good capacity retention, reversible cycling behavior at low temperatures. The good performance can be attributed to the decrease in the freezing point and the polarization of the composite electrolyte.


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