Field performance of Solanum sisymbriifolium, a trap crop for potato cyst nematodes. II. Root characteristics

Abstract

Hatching of potato cyst nematodes is induced by root exudates of Solanaceae, such as Solanum sisymbriifolium, and is therefore related to root length distribution of this crop. A mathematical model was derived to relate the hatching potential to root length density (RLD). A series of field experiments was carried out to study actual root length distribution of S. sisymbriifolium in relation to shoot properties and to provide input into the model. Using a modified Poisson distribution formula for the three-dimensional distribution of roots in a volume of soil, the relation between the zone of influence of hatching agents and the RLD could be derived. On this basis, the minimal RLD was estimated, which is needed to expose 75%, 90% or 95% of cysts to root exudates, as a function of the length of the zone of influence of hatching agents on cysts. The logarithm of the total root length showed a linear relation with the logarithms of above-ground biomass and with leaf area index. Root diameter distribution was the same for all crops examined and independent of soil depth. Fine roots (<0.4 mm in diameter) constituted around 50% of total root length. Using a zone of influence of 1.00, 0.75 and 0.50 cm around the centre of each root, a minimal RLD for sufficient soil exploration (75%) was estimated. Depth at which that minimal RLD was exceeded was linearly related to total root length (km m 22 ) and to above-ground crop biomass, enabling estimations being made of the potential hatching efficacy as related to measurable properties of S. sisymbriifolium crops. The proposed approach to derive potential hatching effects from crop properties needs further validation; particularly, the distance of influence of root exudates is a critical factor.

Phenology, Growth and Yield of Three Wheat (Triticum aestivum L.) Varieties as Affected by High Temperature Stress

“…Chakrabarti et al (2011) conducted a field experiment in India and found that air temperature <15°C was not suitable for the growth and development (germination, seedling stand establishment and tillering) of spring wheat. Timmermans et al (2007) reported that seedling emergence and establishment in Solanum sisymbriifolium, when planted late, were negatively affected by low temperature during germination. At the time of our present research, the maximum temperature during the germination period was >26 to 28°C, sometimes nearing 30°C, while the minimum temperature was between 12 and 13°C, in OS.…”

Plant Root Secretions and Their Interactions with Neighbors

“…Several hatching factors have been identified in crop plants to explore the potential of using these compounds for agrochemical use (Devine and Jones 2001;Timmermans et al 2007). For example, Solanum sisymbriifolium is being used successfully as a trap crop for potato cyst nematodes in Europe, because the plant root exudates stimulate hatching of the second-stage juveniles but does not support their development to complete their life cycle (Timmermans et al 2007). Mostly, the root exudates act as attractants for nematodes to move closer to individual host roots; these are considered "short distance attractants."…”

Assessment of an organ-specific de novo transcriptome of the nematode trap-crop, Solanum sisymbriifolium

“…Solanum sisymbriifolium (SSI), otherwise known as “litchi tomato”, “ morelle de Balbis ”, or “sticky nightshade”, is an undomesticated relative of potato and tomato. For more than a decade, SSI has been investigated as a trap-crop (a plant that attracts nematodes but kills them before they can reproduce) for nematodes such as Globodera pallida that normally parasitize potatoes and tomatoes (Timmermans, 2005; Dandurand and Knudsen, 2016). It is also a potential source of anti-protozoan (Meyre-Silva et al ., 2013) and anti-molluscan (Bagalwa et al ., 2010) metabolites.…”