Effect of Meloidogyne ethiopica parasitism on water management and physiological stress in tomato

Abstract

Root-knot nematodes (RKN) are obligate endoparasites that severely damage the host root system. Nutrient and water uptake are substantially reduced in infested plants, resulting into altered physiological processes and reduced plant growth. The effect of nematode infestation on the morphological changes of roots and subsequent physiological plant responses of infested tomatoes with the RKN Meloidogyne ethiopica was studied in a pot experiment. Plants were infested with two inoculum densities (10 or 50 eggs per cm 3 substrate) and its effect was evaluated 74 and 102 days post inoculation (DPI). Morphological changes and root growth was determined by analysing scanned images of the whole root system. Nematode infestation reduced the portion of fine roots and increased that of coarse roots due to gall formation. Fine roots of non-infested control plants represented around 51% of the area of the whole root system at 74 and 102 DPI. In comparison to controls, plants inoculated with low and high nematode density had 2.1 and 3.2-times lower surface area of fine roots at 102 DPI. Root analyses revealed that plants had a very limited ability to mitigate the effects of the root-knot nematodes infestation by altering root growth. Root galls had a major influence on the hydraulic conductivity of the root system, which was significantly reduced. The low leaf water potential of infested plants coincided with decreased stomatal conductivity, transpiration and photosynthesis. The latter two were reduced by 60-70% when compared to non-infested control plants.

Discrimination between abiotic and biotic drought stress in tomatoes using hyperspectral imaging

“…infestation of plants such as tomato (Solanum lycopersicum) can influence plant physiological parameters (e.g. photosynthesis) measured on the leaf canopy [33]. Strajnar et al [34] have shown the potential of hyperspectral imaging to detect Meloidogyne spp.…”

Plant‐parasitic nematodes of potential phytosanitary importance, their main hosts and reported yield losses

“…Meloidogyne ethiopica Whitehead, 1968 Pathogenic to kiwi fruit (Carneiro et al, 2003), grape (Di Vito et al, 2009) and tomato (Strajnar et al, 2012). Potential quarantine species in Europe.…”

Root-Knot Nematode (Meloidogyne javanica) – Deficit Irrigation Interactions on Eggplant Cropped under Open Field Conditions

“…They develop on the extensive root systems of both annual and perennial crops, damage the root system severely and cause economic losses of more than 12% annually worldwide (Sasser 1987); about 5% of the crop losses are caused by a widely distributed group of plant-parasitic nematodes that are usually known as the root-knot nematodes (Sasser et al 1983;Sasser & Freckman 1987;Siddiqui et al 2003). Plants infected by root-knot nematodes show stunted growth accompanied by symptoms of severe deficiency of some nutritional elements, substantially reduced nutrient and water uptake, and yield amount and quality (Khyami-Horani & AlBanna 2006;Strajnar et al 2012). …”