The Physiological and Biochemical Effects of Phthalic Acids and the Changes of Rhizosphere Fungi Diversity under Continuous Cropping of Lanzhou Lily (Lilium davidii var. unicolor)

Abstract

<jats:p>The autotoxicity of root exudates and the change of rhizosphere soil microbes are two important factors that affect the quality and yield of Lanzhou lily (<jats:italic>Lilium davidii</jats:italic> var. <jats:italic>unicolor</jats:italic>). Phthalic acid (PA) is a major autotoxin of the root exudates in Lanzhou lily. In this study, we treated plants with different concentrations of PA from the Lanzhou lily root exudates and then analyzed the effects of autotoxins on fresh weight, shoot height, root length, and Oxygen Radical Absorbance Capacity in root. The diversity of soil fungi in Lanzhou lily soil was analyzed using MiSeq. The results showed that PA induced oxidative stress and oxidative damage of Lanzhou lily roots, improved the level of the membrane lipid peroxidation, reduced the content of antioxidant defense enzyme activity and the nonenzymatic antioxidant, and eventually inhibited the growth of the Lanzhou lily. We found that continuous cropping of Lanzhou lily resulted in an increase in fungal pathogens, such as <jats:italic>Fusarium oxysporum</jats:italic> in the soil, and reduced the size of plant-beneficial bacteria populations. The results in this study indicate that continuous cropping would damage the regular growth of Lanzhou lily.</jats:p>

Soil Fungal Diversity Loss and Appearance of Specific Fungal Pathogenic Communities Associated With the Consecutive Replant Problem (CRP) in Lily

“…However, since different biological agents have been implicated in disease development, there is no typical symptom occurrence with CRPs, so it is difficult to diagnose a CRP by only aboveground symptoms. A recent publication reported soil fungal community dynamics of Lanzhou lily in 3 years of one cultivation cycle (Hua et al, 2019), however, their dynamics under long term replant system and their roles in the lily CRPs have not been reported.…”

Nitrogen Fertilization in a Faba Bean–Wheat Intercropping System Can Alleviate the Autotoxic Effects in Faba Bean

“…As the essence of Chinese traditional agriculture, intercropping is an effective measure to alleviate the negative effects of continuous cropping by combining land use and land maintenance in agricultural production [ 41 ]. Reasonable intercropping can reduce the autotoxic effect and negative effect of continuous cropping [ 42 , 43 ]. Through the water culture and pot experiment, Zhao et al proved that American ginseng and P. frutescens intercropping could effectively overcome the autotoxic effect of the continuous cropping of American ginseng [ 16 ].…”

Soil Microbial Community Driven by Soil Moisture and Nitrogen in Milk Vetch (Astragalus sinicus L.)–Rapeseed (Brassica napus L.) Intercropping

“…That is why, in our study, the dominant phyla were Chloroflex, Proteobacteria, Actinobacteria, Acidobacteria, Firmicutes, Gemmatimonates and Bacteroidetes, in both intercropping and monoculture (Figure 4). Intercropping will have a certain impact on the soil environment due to differences in crop coverage [50], residues [62] and root exudates [63]; these factors change the characteristics of the microorganisms [64], but this change is limited, and generally only leads to significant changes in some extremely sensitive microbial communities [65,66]. In addition, general studies have shown that intercropping can change the soil microbial community structure and functional activity by changing the input of fresh organic matter [67,68].…”