scholarly journals The Influence of the Hatching Factor on the Water Uptake of the Second Stage Larva of the Potato Cyst Nematode Heterodera Rostochiensis

1976 ◽  
Vol 64 (1) ◽  
pp. 141-147
Author(s):  
C. ELLENBY ◽  
R. N. PERRY

1. Larvae-containing eggs of the potato cyst nematode were soaked in root diffusate in artificial tap water or in artificial tap water alone. In one experiment, the eggs were still contained in intact cysts; in another experiment they were in a halved cyst. 2. Eggs were ruptured after 0–5 days treatment and the water content of the liberated larvae immediately estimated by interference microscopy. 3. Larvae from treated eggs from both the halved and intact cysts had a higher water content than controls. 4. Larvae liberated from treated eggs from the halved cyst reached their maximum water content after 24 h treatment; those from intact cysts attained the same value after 2 days. The delay, for the intact cyst, is in keeping with the hatching response for intact cysts and supports the view that the results for water content are due to the activity of the hatching factor. 5. Reasons are advanced for the view that the hatching factor may work via a neurosecretory mechanism.

1974 ◽  
Vol 61 (3) ◽  
pp. 773-779
Author(s):  
C. ELLENBY

1. The second-stage larva of the plant parasitic nematode Heterodera rostochiensis shows very little movement while confined to the egg; on the other hand, the larva of the closely related Meloidogyne incognita is very active 2. Using interference microscopy, it is shown that the water content of the Heterodera larva increases immediately it is liberated from the egg while that of the Meloidogyne larva remains constant. 3. It is suggested that the Heterodera larva is physically constricted by the egg shell and that this restricts both its movement and its water content. 4. Measurement of larval and egg volume in both forms supports this hypothesis. The Meloidogyne larva has about 30% of free space inside the egg shell while the Heterodera larva fits it completely. 5. It is suggested that these differences can be correlated with differences in the distribution and life-history of the two forms.


2005 ◽  
Vol 53 (2) ◽  
pp. 153-159 ◽  
Author(s):  
A. C. Dobos ◽  
G. Szabó

Tests were made on the water dynamics of water loss in maize at two locations at major maize production areas, Debrecen and Szeged, as a function of the heat sum required up to physiological ripening. The maximum water content was found to vary according to the hybrid and the year. No significant differences were found between the effective heat sums associated with maximum values within a year, the difference being 2-4 calendar days. There was a close correlation between the maximum grain water content and the length of the generative phase for a given hybrid in a given year. Better water supplies (1998) resulted in higher maximum water content values, which indirectly promoted longer and more intensive dry matter incorporation. Of all the environmental parameters, the drying down rate is primarily determined by the temperature. The changes in grain moisture content in a specific hybrid can be characterised by a joint linear graph. The drying down rate of the individual hybrids was determined by examining the b term of the linear equation.


2012 ◽  
Vol 457-458 ◽  
pp. 435-438
Author(s):  
Xue Dong Guo ◽  
Cao Jian ◽  
Xiang Yang Fang

In this paper,study water content and water stability of AC and SMA asphalt mixtures, and reach the following conclusions. In the normal saturated condition, the maximum water content of AC and SMA asphalt mixture is 0.28% and 0.32%.And in the vacuum saturated condition, the maximum water content of AC and SMA asphalt mixture is 0.8% and 0.78%.The water of AC and SMA asphalt mixture separately take 8 days and 9 days to drain completely in the normal saturated condition. But in the vacuum saturated condition, the time is more than two months. In different water content conditions, the splitting tensile strength of AC asphalt mixture is 0%> 100%> 25%> 75%> 50%.But the splitting tensile strength of SMA asphalt mixture is 0%> 100%> 25%> 50%> 75%.


2017 ◽  
Vol 21 (1) ◽  
pp. 59-68
Author(s):  
Krzysztof Kornarzyński ◽  
Bożena Gładyszewska

Abstract The objective of the paper was to investigate the moisture change ability of bean, broad bean, pea, lupine, radish, beetroot, winter wheat, maize, cucumber, pumpkin and sunflower seeds. Seeds absorbed water in the system for measurement of the water absorption kinetics with the capillary and weighting method. The research results were presented in the form of plots of the relation of kinetics of the moisture change of seeds in the time for the first and second stage of the process which precedes germination. Moreover, the water content in seeds for the time of the end of the second stage of water absorption was determined and the maximum water absorption speed coefficient and the time of its obtaining was calculated. The water content for the end of the 2nd stage of its collection was the highest for seeds which include a hard caryopsis and for broad bean plant seeds. The maximum water absorption speed coefficient was the highest for seeds with low initial moisture - radish, beetroot, cucumber and pumpkin. The measurement of the water absorption speed with the use of the capillary and weighting method enabled investigation of seeds with a varied size, construction of a seed coat and chemical composition for a long period of time to the moment seedlings were obtained.


2015 ◽  
Vol 21 (2) ◽  
pp. 221
Author(s):  
Lucas Cavalcante Da Costa ◽  
Fernanda Ferreira De Araújo ◽  
Teresa Drummond Correia Mendes ◽  
Fernando Luiz Finger

<p>Several experiments reveal that distilled water varies among different laboratories and also does not have a standard composition. Water electrical conductivity (EC) of vase solution is one of the parameters that influence the water uptake by cut flowers. Therefore, the objective of this work was to evaluate the influence of electrical conductivity on water uptake and vase life in cut stems of gladiolus. The stems harvested and kept in distilled water (pH 6.6, EC &lt;0.01dS m-1) and tap water (pH 7.0, EC 0.75 dS m-1) at room temperature. Flowers kept in tap water showed lower fresh weight loss after the second day and higher water uptake during vase life. In a second set of experiments, we verified the limit EC saturation supported by the flower. For this, flowers were placed in individual test tubes containing four different solutions with varying ion concentrations. Solution 2 (EC 0.60 dS m-1) promoted increased vase life and allowed maximum water uptake by the flowers. The results show that the electrical conductivity of vase solution is a major parameter in experiments with vase life of cut gladiolus. The presence of ions in the vase solution increases the overall vase life and improves water uptake of flowers with favorable optimal EC between 0.60 to 0.87 dS m-1.</p>


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