Tuber Yield, Quality and Infestation Levels of Potato Genotypes, Resistant to the Root-Knot Nematode, Meloidogyne chitwoodi

Abstract

As part of developing a routine potato cultivars resistance test to Meloidogyne chitwoodi, both the effect of nematode density (Pi) and pot size on growth, tuber yield, quality and tuber infestation level were studied in glasshouse conditions. The study was carried out in four experiments using cv. Desiree as control and seven genotypes with a single resistance gene to M. chitwoodi and 1 genotype, with resistance to Globodera pallida. Plants were inoculated with ranges of Pi from 0.0625 to 256 J2 (g dry soil)−1 in log series. Haulm height, tuber yield, starch dry matter content (SDC) and tuber quality were recorded. Additionally, harvested tubers of experiment 2 were stored for 240–300 days to estimate actual tuber infestation at planting when used as seed in a subsequent season. Haulm height was positively affected with increasing Pi’s and negatively with decreasing pot size. The yield was not affected in four out of seven genotypes with resistance to M. chitwoodi; they can be considered as tolerant, having a relative minimum yield, m = 1. Three genotypes and cv. Desiree showed relative minimum yield, m< 0.8, the latter varying between 0.67 and 0.80 over experiments and pot sizes. The reduction of SDC equalled that of yield indicating that M. chitwoodi had no extra effect on starch content. Quality, expressed as tuber-knot index (TKI), used for accepting ware potatoes for processing, was below 10 for all genotypes, except for 2011M1. The TKI values of cv. Desiree and genotype MDG2 were > 20 and are not accepted for processing. The fraction of clean tubers of the resistant genotypes had significantly increased to 91% compared to < 8% for cv. Desiree and MDG2. Tuber infestation, expressed to number of juveniles per gram dry soil of cv. Desiree after storage, showed no regression with the Pi and averaged 0.35 J2 (g dry soil)−1, while all tested genotypes provided ca. 0.002 J2 (g dry soil)−1.

From root to shoot; Quantifying nematode tolerance inArabidopsis thalianaby high-throughput phenotyping of plant development

“…Yet, the overall density response in our data fitted the model well. Similar observations were made previously where the Te strongly deviated between biological replicates (Teklu et al, 2022). We conclude that although the SYLM does not perform well at low-densities, it is suitable to predict minimal yields.…”

“…The first measurable repression in plant growth (i.e., yield, plant height) by pathogen infection is defined as the tolerance limit (Seinhorst, 1985). The tolerance limit of plants is measured independently from resistance because tolerance and resistance are genetically and physiologically independent traits (Evans & Haydock, 1990;Teklu et al, 2022). The tolerance limit is dependent on the plant and the nematode species, and the interaction between those two.…”

“…Another returning hurdle in tolerance research is to determine which plant trait should be measured. Most of the studies on tolerance to root-parasitic nematodes in potato focus on yield reduction, e.g., potato yield expressed in tuber weight and quality (Been et al, 2015;Teklu et al, 2022), which depend on single destructive endpoint measurement. Others also measure the effect of nematodes foliage or plant height which are not perse destructive (Norshie et al, 2011), but these types of measurements are less often done because they are laborious.…”

Evaluation of Solanum linnaeanum and S. sisymbriifolium extracts for the management of Meloidogyne chitwoodi

“…When M. chitwoodi is detected in seed potato lots, zero tolerance is generally applied, and the tolerance by the market for the tuber damage caused by it is very low. However, for industrial processing, there are acceptable limits even though they vary from country to country [ 57 ]. Despite the level of M. chitwoodi reproduction being reduced by exposure to the extracts at a concentration of 0.8 mg/mL, relative to the control, the RF it is still higher than 2.…”

WOX11-mediated cell size control in Arabidopsis attenuates fecundity of endoparasitic cyst nematodes

“…Samples were sent to the NAK (Emmeloord, The Netherlands) for automated cyst extraction. Cysts were crushed and the number of eggs and J2s per cyst was counted following the protocol by Teklu et al . (2018).…”