International Journal of Nematology (2005) 15, 100-106

H.C. Meher, H.S. Gaur, G. Singh and P. Venkatesan (2005)
alpha -Tomatine in tomato and resistance against root-knot nematode, Meloidogyne incognita
International Journal of Nematology 15 (1), 100-106
Abstract: Plants of the family Solanaceae are known to synthesize glycoalkaloids (GA) as defence compounds to impart resistance against phytopathogens. GAs are acetylcholine esterase inhibitors as well as reducer of LDL cholesterol and anticarcinogenic. Very little information is available regarding the effect of GA on nematode resistance. The level of alpha-tomatine was assessed in resistant and susceptible tomatoes, Lycopersicon esculentum (Mill.) grown in field infested with root-knot nematode, Meloidogyne incognita, and reniform nematode, Rotylenchulus reniformis, using Liquid Chromatography (LC). alpha-Tomatine proved to be a good bio-molecular resistance marker in tomato against M. incognita. Its level in roots of resistant transplants was higher than susceptible ones. Fifteen days after transplanting, alpha-tomatine level increased three-fold in resistant compared to susceptible cultivars. This was accompanied by concomitant increase in the level of alpha-tomatine in shoot. In fruit, the alpha-tomatine level declined more rapidly in resistant than susceptible cultivars on maturity from green to red fruit. alpha-tomatine level in different test cultivars was considered safe. The reduction in root-knot nematode population in soil could be correlated with decrease in root galling of tomato (r=0.83*), which in turn could be ascribed to the maximum alpha-tomatine level in roots (r=0.78*). However, the cultivars resistant to M. incognita were not resistant to R. reniformis. The study also demonstrated potential of LC for rapid and reliable screening of tomato germplasm for root-knot nematode resistance.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Hari S. Gaur

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Meloidogyne incognita	Tomato (Solanum lycopersicum)	India
	Rotylenchulus reniformis	Tomato (Solanum lycopersicum)	India