Temporal Interactions between Root-Lesion Nematodes and the Fungus Rhizoctonia Solani Lead to Reduced Potato Yield

Abstract

Soil microorganisms and soil fauna may have a large impact on the tuber yield of potato crops. The interaction between root-lesion nematodes and the pathogenic fungus Rhizoctonia solani Kühn was studied on potato plants grown in pots under controlled conditions. In two similar experiments, different combinations of nematodes and fungal mycelium were added to the pots at three occasions; at planting, after 14 days, and after 28 days. The nematodes reduced root biomass and the combination of nematodes and R. solani resulted in reduced tuber yield in both experiments, but the interaction was not synergistic. In contrast, the number of stem canker lesions decreased in the presence of nematodes compared to treatments with R. solani only. The time of inoculation influenced the severity of both fungal and nematode damage. The nematode damage on tubers was less severe if the nematodes were added at 28 days, while the number of severe stem canker lesions increased if the fungus was added at 28 days. However, the time of nematode inoculation did not affect the incidence of fungal damage, hence the nematodes did not assist R. solani to infect the plant. Our results highlight the underestimated importance of root-lesion nematodes, not resulting in obvious above ground symptoms or misshaped tubers yet affecting the performance of other pathogens.

Additive effect of the root-lesion nematode Pratylenchus penetrans and the fungus Rhizoctonia solani on potato yield and damage

“…In addition, the grading of damages in experiment 1 was insufficient, indicating a need for a second experiment to be able to address the hypotheses properly. The second experiment was part of a larger experiment (Edin et al 2019).…”

“…An isolate of Rhizoctonia solani, anastomosis group 2 (AG2-1), originating from Vara, Sweden, was kindly provided by Dr. S. Ahlström at the Department of Forest Mycology and Plant Pathology, SLU, Uppsala, Sweden, which was the same isolate used in the experiments previously published (Edin and Viketoft 2017;Viketoft et al 2017;Edin et al 2019). The methodology was also the same as in those experiments, i.e.…”

Special Issue “Integrated Defense Responses in Crops against Soil-Borne Pathogens”

“…Two articles report on plant stress responses. The time-dependency in the pathogen-pathogen interaction of potato with both root-lesion nematodes and the pathogenic fungus Rhizoctonia solani, was demonstrated by Edin and co-workers [13]. A second paper shows a dual challenge with a root knot nematode and the pathogenic fungus Fusarium oxysporum, in which two tomato genotypes with different levels of resistance against those pathogens exhibit specific photosynthetic responses and oxidative stress signatures [14].…”

Buğdayda Pratylenchus thornei ve Rhizoctonia solani Etkileşimi

“…Bir bitki aynı anda birden çok bitki patojeni ve zararlı tarafından istila edilebilir. Bitki patojeni funguslar ve nematodlar aynı bitkide birlikte ortaya çıktıklarında bağımsız olarak hareket edebilir ve hasar ve verim üzerinde ilave bir etkiye neden olabilir veya sırasıyla daha fazla ve daha az hasara yol açan sinerjistik veya antagonistik bir şekilde birbirleriyle etkileşime girebilirler [33,34]. Bitki paraziti nematod ve fungus etkileşimlerinin arkasında birkaç olası mekanizma vardır.…”