Tomato root diffusate

Figure 3. Hatching stimulating activity of the freeze-dried (A) and freshly prepared (B) tomato root diffusate (TRD), and the effect of addition of a highly volatile fraction ofTRD (C).

The tomato root diffusate obtained from a hydroponic culture medium was concentrated with a rotary evaporator to give solid residue and concentrated aqueous extract. A vacuum line was connected to two traps in series trap I (-45 °C) and trap II (-196 °C). The water condensed from the rotary evaporator in trap I gave a pair of synergists, which were referred to as lA and IB (SylA and SylB). The highly volatile synergist was obtained in the trap, and was referred to as synergist II (Syll). 

Hatching Stimulator, Hatching Synergist, Potato Cyst Nematode, Globodera rostochiensis, Heterodera glycines. Tomato Root Diffusate... 

Diffusion-mediated release of root exudates is likely to be affected by root zone temperature due to temperature-dependent changes in the speed of diffusion processes and modifications of membrane permeability (259,260). This might explain the stimulation of root exudation in tomato and clover at high temperatures, reported by Rovira (261), and also the increase in exudation of. sugars and amino acids in maize, cucumber, and strawberry exposed to low-temperature treatments (5-10°C), which was mainly attributed to a disturbance in membrane permeability (259,262). A decrease of exudation rates at low temperatures may be predicted for exudation processes that depend on metabolic energy. This assumption is supported by the continuous decrease of phytosiderophore release in Fe-deficient barley by decreasing the temperature from 30 to 5°C (67). 

Stolzy, L. H., O. C. Taylor, W. M. Dugger, Jr., and J. D. Mersereau. Physiological changes in and ozone susceptibility of the tomato plant after periods of inadequate oxygen diffusion to the roots. Proc. Soil Sci. Soc. Amer. 28 305-308, 1964. 

After an intensive effort to isolate the hatching factors from host plant roots or their diffusates, Masamune s group hrst established the structure of hatching stimulant to SCN, glycinoeclepin A, in 1982, which was active at a concentration of as low as 10 g/niL (Figure 1) [5-8]. Subsequently, solanoeclepin A was reported as the stimulant to PCN by Mulder et al. in 1992 [9]. This compound was isolated from the hydroponic culture medium of tomato and active at 10 g/mL in an aqueous solution. In spite of their ultra-high activity, neither of these compounds has been commercialized as nematicides because of their limited solubility in water. Besides, recent research reveals that the reality of chemical hatching control is not that simple. 

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