Crop Rotation with Marigold Promotes Soil Bacterial Structure to Assist in Mitigating Clubroot Incidence in Chinese Cabbage

Abstract

Clubroot caused by Plasmodiophora brassicae is an economically important soilborne disease of Chinese cabbage worldwide. Integrated biological control through crop rotation is considered a good disease management approach to suppress the incidence of soilborne diseases. In this study, we evaluated the effect of a marigold plant (root exudates, crude extract, and powder) on the germination and death of resting spores of P. brassicae in vitro assays. Additionally, we also performed 16S high throughput sequencing, to investigate the impact of marigold–Chinese cabbage crop rotation on soil bacterial community composition, to manage this devastating pathogen. This study revealed that the marigold root exudates, crude extract, and powder significantly promoted the germination and death of P. brassicae resting spores. Under field conditions, marigold–Chinese cabbage crop rotation with an empty period of at least 15 days enhanced the germination of P. brassicae resting spores, shifted the rhizosphere bacterial community composition, and suppressed the incidence of clubroot by up to 63.35%. Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, and Verrucomicrobia were the most dominant phyla and were present at high relative levels in the rhizosphere soil of Chinese cabbage. We concluded that crop rotation of Chinese cabbage with marigold can significantly reduce the incidence of clubroot disease in the next crop. To our knowledge, this is the first comprehensive study on the prevention and control of clubroot disease in Chinese cabbage through crop rotation with marigold.

Pre-soil fumigation with ammonium bicarbonate and lime modulates the rhizosphere microbiome to mitigate clubroot disease in Chinese cabbage

“…The greenhouse experiment was performed from March to May 2021 under controlled conditions: 30/18°C day/night temperature and 10/14 h light/dark photoperiod ( Zhang et al, 2022b ). The pots (24 × 18 cm diameter) were filled with 3.5 kg/pot of diseased soil heavily infected with clubroot pathogen collected from the field (Xiadabai County, Kunming, China).…”

“…The control effect (CE), disease index (DI), and disease incidence (Di) were assessed at the end of the experiment, while soil pH was measured after soil fumigation and the end of the experiment. The Di, DI, and CE were calculated according to a five-point disease scoring scale and formulas ( Zhang et al, 2022b ). The soil pH was calculated in a 2.5:1 water/soil (V/W) suspension using a pH meter ( Zhang et al, 2022a ).…”

Effect of marigold (Tagetes erecta L.) on soil microbial communities in continuously cropped tobacco fields

“…Marigold rotation, intercropping and mulching could effectively inhibit nematodes infection in eggplant, tomato and soybean 19 , 20 . The rotation of Chinese cabbage and marigold can significantly reduce the incidence of clubfoot disease in the next crop 21 . In addition, marigold can also impact soil microbial communities: intercropping marigold with tobacco can increase the diversity of rhizosphere soil bacterial communities 22 .…”

Interaction of Plants and Endophytic Microorganisms: Molecular Aspects, Biological Functions, Community Composition, and Practical Applications

“…In addition, five papers are concerned with studying the relationship between the quality of the soil and the substances introduced into it via the endophytic biodiversity of plants [ 14 , 15 , 16 , 17 , 18 ]. The rhizosphere and endophytic microbiome of the bamboo plant were evaluated in response to the prolonged application of heavy organic fertilizers [ 14 ].…”

“…It was characterized root-associated microbiomes of rice plants during co-planted barnyard grass stress and a comparison with the microbiomes of unplanted soil [ 15 ]. The results of a comprehensive study on the prevention and control of clubroot disease (caused by Plasmodiophora brassicae ) in Chinese cabbage through crop rotation with marigold [ 16 ] were described for the first time. Additionally, we habe presented results from a temporal variability in late blight pathogen diversity, virulence and fungicide resistance in potato breeding fields [ 17 ].…”