Effect of Two Kinds of Fertilizers on Growth and Rhizosphere Soil Properties of Bayberry with Decline Disease

Abstract

Decline disease causes severe damage to bayberry. However, the cause of this disease remains unclear. Interestingly, our previous studies found that the disease severity is related with the level of soil fertilizer. This study aims to explore the effect and mechanism of compound fertilizer (CF) and bio-organic fertilizer (OF) in this disease by investigating the vegetative growth, fruit characters, soil property, rhizosphere microflora and metabolites. Results indicated that compared with the disease control, CF and OF exhibited differential effect in plant healthy and soil quality, together with the increase in relative abundance of Burkholderia and Mortierella, and the reduction in that of Rhizomicrobium and Acidibacter, Trichoderma, and Cladophialophora reduced. The relative abundance of Geminibasidium were increased by CF (251.79%) but reduced by OF (13.99%). In general, the composition of bacterial and fungal communities in rhizosphere soil was affected significantly at genus level by exchangeable calcium, available phosphorus, and exchangeable magnesium, while the former two variables had a greater influence in bacterial communities than fungal communities. Analysis of GC-MS metabonomics indicated that compared to the disease control, CF and OF significantly changed the contents of 31 and 45 metabolites, respectively, while both fertilizers changed C5-branched dibasic acid, galactose, and pyrimidine metabolic pathway. Furthermore, a significant correlation was observed at the phylum, order and genus levels between microbial groups and secondary metabolites of bayberry rhizosphere soil. In summary, the results provide a new way for rejuvenation of this diseased bayberry trees.

Effect of Fungicides on Bayberry Decline Disease by Modulating Rhizosphere Soil Properties, Microflora, and Metabolites

“…The relative abundance of Acidibacter decreased by 39.29% (Figure 3A), which is the same as the decreased change direction of the decline-diseased soil given the treatment with two fertilizers [24]. The abundance of Acidothermus did not change significantly (Figure 3A), which is different from the increased change seen in the compound fertilizer and the decreased change seen in the bio-organic fertilizer treatment on the decline-diseased soil [24]. Burkholderia, which has nitrogen fixation and potential growthpromoting effects, can improve plant production; the activities of soil sucrose, catalase, urease, and phosphatase; and the expression of defense-related genes [25,26].…”

“…The main genera (average relative abundance > 1%) were Mortierella, Trichoderma, Geminibasidium, and Cladophialophora, which were amongst the top 15 dominant fungal genera in terms of the distribution and relative abundance of fungal species in the rhizospheric soil at the genus level, which accounts for >75% of fungal sequences (Figure 3B). The relative abundance of Geminibasidium was significantly increased by 99.86%, which is the same as the increased change direction of the compound fertilizer treatment of the decline-diseased soil but different from the decreased change direction seen for the bio-organic fertilizer treatment [24]. The relative abundance of Trichoderma and Cladophialophora was significantly decreased by 33.51% and 9.95%, respectively, which is the same as the decreased change direction of the compound and bio-organic fertilizer treatment of the decline-diseased soil [24].…”

“…The relative abundance of Geminibasidium was significantly increased by 99.86%, which is the same as the increased change direction of the compound fertilizer treatment of the decline-diseased soil but different from the decreased change direction seen for the bio-organic fertilizer treatment [24]. The relative abundance of Trichoderma and Cladophialophora was significantly decreased by 33.51% and 9.95%, respectively, which is the same as the decreased change direction of the compound and bio-organic fertilizer treatment of the decline-diseased soil [24]. There was no significant change in the relative abundance of Mortierella, which is different from the increased change direction seen for the two-fertilizer treatment of the decline-diseased soil [24].…”

“…The results showed that the main bacterial genera with a >1% relative abundance include Acidibacter, Rhizomicrobium, Acidothermus, and Burkholderia. The relative abundance of Burkholderia and Rhizomicrobium in the rhizosphere soil of the prochloraz treatment group was significantly increased by 141.27% and 11.99%, respectively, compared to the disease control group (Figure 3A), which is the same as the increased change direction of the decline-diseased soil given the treatment with two fertilizers [24]. The relative abundance of Acidibacter decreased by 39.29% (Figure 3A), which is the same as the decreased change direction of the decline-diseased soil given the treatment with two fertilizers [24].…”

“…The relative abundance of Burkholderia and Rhizomicrobium in the rhizosphere soil of the prochloraz treatment group was significantly increased by 141.27% and 11.99%, respectively, compared to the disease control group (Figure 3A), which is the same as the increased change direction of the decline-diseased soil given the treatment with two fertilizers [24]. The relative abundance of Acidibacter decreased by 39.29% (Figure 3A), which is the same as the decreased change direction of the decline-diseased soil given the treatment with two fertilizers [24]. The abundance of Acidothermus did not change significantly (Figure 3A), which is different from the increased change seen in the compound fertilizer and the decreased change seen in the bio-organic fertilizer treatment on the decline-diseased soil [24].…”