The effect of the potato cyst nematode Globodera pallida on in vitro root growth of potato genotypes, differing in tolerance

Abstract

Roots of eighteen potato genotypes, differing in tolerance of G. pallida, were grown from tuberpieces on agar in Petri dishes. Juveniles of G. pallida were inoculated directly onto root tips. Root length was measured at various times after inoculation. Inoculation reduced root growth within one day. At later stages, genotypes differed strongly in growth of inoculated roots. Between four and seven days after inoculation, growth of inoculated roots was not significantly correlated with growth of untreated roots, and was only poorly correlated with tolerance assessed in the greenhouse or in the field. However, multiple regression analysis revealed that the tolerance of the tested genotypes was associated with both the rate at which they induced hatching and the growth of roots after inoculation. The combination of these two variables accounted for high percentages explained variance.

Breeding for potato cyst nematode resistance in Solanum tuberosum

“…As nematodes enter and move through the roots, they also inflict physical damage, which makes the plant susceptible to secondary infections from other pathogens (Back et al., 2006; Bhattarai et al., 2009; Evans, 1987; Storey & Evans, 1987). Additionally, PCNs impair root function by reducing root elongation (Arntzen et al., 1994) and decreasing nutrient uptake (De Ruijter & Haverkort, 1999; Trudgill, 1987). This leads to stunted potato crop growth and yellowing leaves (EFSA et al., 2019).…”

Why Do Plants Need Defenses?

“…In clover, the stem nematode, Ditylenchus dipsaci, reduced establishment from seeds and led to a 30% reduction in shoot growth (Cook et al, 1992), while the potato cyst nematodes, Globodera pallida and Globodera rostochiensis, reduced growth of potato roots within 1 day following inoculation onto root tips (Arnitzen et al, 1994). In clover, the stem nematode, Ditylenchus dipsaci, reduced establishment from seeds and led to a 30% reduction in shoot growth (Cook et al, 1992), while the potato cyst nematodes, Globodera pallida and Globodera rostochiensis, reduced growth of potato roots within 1 day following inoculation onto root tips (Arnitzen et al, 1994).…”