scholarly journals Global Methyl Halide Emissions From Rapeseed ( Brassica napus ) Using Life Cycle Measurements

2020 ◽  
Vol 47 (19) ◽  
Author(s):  
Yi Jiao ◽  
Jerrold Acdan ◽  
Rong Xu ◽  
Malte Julian Deventer ◽  
Wanying Zhang ◽  
...  
Keyword(s):  
Life Cycle ◽  
Brassica Napus ◽  
Methyl Halide

Effect of temperature on the life cycle of Heterodera schachtii infecting oilseed rape (Brassica napus L.)

Nematology ◽  
2012 ◽  
Vol 14 (7) ◽  
pp. 855-867 ◽  
Author(s):  
Stephen Kakaire ◽  
Ivan G. Grove ◽  
Patrick P.J. Haydock
Keyword(s):  
Life Cycle ◽  
Brassica Napus ◽  
Oilseed Rape ◽  
Second Generation ◽  
Cultivar Differences ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Degree Days ◽  
Temperature Range ◽  
The Uk

Oilseed rape (OSR; Brassica napus L.) is a crop of increasing world importance and suffers yield loss when infected with Heterodera schachtii. The in vitro hatch, in planta root invasion and development of a field population of H. schachtii were investigated in six thermostatically-controlled water baths at temperatures of 5.0, 10.1, 20.5, 27.8, 32.2 and 37.5°C in a glasshouse. The UK winter OSR cvs Flash and Castille were used. Temperature was shown to have a major influence on the development of H. schachtii in OSR. The highest cumulative percentage hatch of second-stage juveniles (J2) observed over an 8-week incubation period occurred between 20.5 and 27.8°C in leachates of both OSR cultivars, indicating that this is the optimum temperature range for hatching of this population. Cumulative hatch was lowest at 37.5 and 5.0°C. Root invasion was inhibited at 5.0 and 37.5°C, whilst the highest number of J2 invaded the roots between 20.5 and 32.2°C, indicating that this is the optimum temperature range for root invasion. The life cycle took between 21 days at 20.5°C and 42 days at 5.0°C from the inoculated J2 to the J2 of the second generation, with the associated accumulated heat units (AHU) of 424 and 203 degree-days with a base temperature (Tb) of 5.0°C. The optimum temperature range (To) for development was between 20.5 and 27.8°C and the maximum (Tm) was 37.5°C. As temperature increased, the AHU required to complete the life cycle increased from 203 degree-days at 5.0°C to 1406 at 37.5°C. Leachates from both OSR cultivars stimulated more J2 to hatch than the distilled water controls. No significant cultivar differences were observed for J2 hatching, root invasion and duration of the life cycle at the different temperatures but significantly more cysts of the second generation (g root)−1 were observed in cv. Flash than cv. Castille at 27.8 and 32.2°C, suggesting that the latter cultivar is a poorer host of H. schachtii than cv. Flash. This is the first report of the effect of temperature on H. schachtii development on current winter OSR cultivars in the UK and provides insight into the potential effects of climate change on the nematode-host interaction.

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

A freeze-fracture-etched study of the physarum polycephalum plasma membrane during early formation of the macroplasmodial stage

1993 ◽  
Vol 51 ◽  
pp. 346-347
Author(s):  
Randolph W. Taylor ◽  
Henrie Treadwell
Keyword(s):  
Plasma Membrane ◽  
Life Cycle ◽  
Growth Phase ◽  
Filter Paper ◽  
Physarum Polycephalum ◽  
Freeze Fracture ◽  
Petri Dish ◽  
Wire Screen ◽  
Wide Mouth ◽  
Sterile Filter

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.

A Spreadsheet Life Cycle Cost Model for System Modernization Studies

1994 ◽  
Vol 11 (1) ◽  
pp. 47-56
Author(s):  
Virginia C. Day ◽  
Zachary F. Lansdowne ◽  
Richard A Moynihan ◽  
John A. Vitkevich
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Cost Model

Hormonal requirement and tissue competency for shoot organogenesis in two cultivars of Brassica napus

1992 ◽  
Vol 84 (4) ◽  
pp. 521-530
Author(s):  
Jacques Julliard ◽  
Lucienne Sossountzov ◽  
Yvette Habricot ◽  
Georges Pelletier
Keyword(s):  
Brassica Napus ◽  
Shoot Organogenesis
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