Department of Plant Science, University of Buea, Buea, Cameroon.
Institute for Nature, Health and Agricultural Research (INHAR), Buea, Cameroon.
PLoS One. 2024 Nov 27;19(11):e0312199. doi: 10.1371/journal.pone.0312199. eCollection 2024.
Chromolaena odorata is a noxious alien invasive weed species with an enormous impact on the terrestrial ecosystem. The allelopathic potentials of this weed have had little attention, leading to changes in soil properties and microbial communities. This study investigates the impacts of Chromolaena odorata invasion gradients on rhizospheric soil chemical properties and microbial response in the Mount Cameroon Region. Forty-eight soil samples at four different degrees of invasion (uninvaded, low degree invasion, moderate degree invasion and high degree invasion) based on species coverage within subplots in four study areas were collected and rhizospheric soil chemical properties, microbial load, phosphatases activities and secondary metabolites were evaluated. At medium-degree invasion, rhizospheric soil concentrations of P, K and Fe increased with arbuscular mycorrhizal fungi (AMF) colonization and phosphatases enzyme activities. Soil C, N and organic matter were significantly increased at high-degree invasion, supporting the use of the plant as a fallow crop. Acid phosphatase activity ranged from 0.69 to 0.90 mmol h-1 kg-1 and was significantly different at different degrees of invasion. AMF colonization ranged from 23.33 to 50.00%, with a strong positive correlation between AMF colonization and phosphatase activity. Soil bacterial load was high (46 × 105 CFU/g- 67 × 105 CFU/g), with mostly Staphylococcus having health concerns about its spread. The invasion situation had no significant effect on soil bacterial load, but high-degree invasion significantly increased fungal load. Low-degree invaded soils had high saponin (24.55±0.00 mg/g), flavonoid (47.7 mg/g) and tannin (28.68 mg/g) concentrations. The investigation reveals that Chromolaena odorata invasion altered rhizospheric soil properties and microbial communities significantly, thereby influencing ecosystem dynamics and soil nutrient availability. However, further studies elucidating kinds of secondary metabolites, identifying microbial communities, and monitoring soil changes influenced by C. odorata are essential for effective ecosystem management.
臭娘子是一种具有巨大生态影响的有害外来入侵杂草。这种杂草的化感潜力很少受到关注，导致土壤性质和微生物群落发生变化。本研究调查了喀麦隆山地区臭娘子入侵梯度对根际土壤化学性质和微生物响应的影响。在四个研究区的子区中，根据物种覆盖率，在四个不同入侵程度（未入侵、轻度入侵、中度入侵和高度入侵）下收集了 48 个土壤样本，并评估了根际土壤化学性质、微生物负荷、磷酸酶活性和次生代谢物。在中度入侵时，随着丛枝菌根真菌（AMF）定殖和磷酸酶酶活性的增加，根际土壤中 P、K 和 Fe 的浓度增加。在高度入侵时，土壤中的 C、N 和有机质显著增加，支持将该植物用作休耕地作物。酸性磷酸酶活性范围为 0.69 至 0.90mmol h-1 kg-1，在不同入侵程度之间有显著差异。AMF 定殖范围为 23.33%至 50.00%，AMF 定殖与磷酸酶活性之间存在很强的正相关。土壤细菌负荷较高（46×105 CFU/g-67×105 CFU/g），其中主要是葡萄球菌，其传播令人担忧。入侵情况对土壤细菌负荷没有显著影响，但高度入侵显著增加了真菌负荷。低入侵土壤具有较高的皂素（24.55±0.00mg/g）、类黄酮（47.7mg/g）和单宁（28.68mg/g）浓度。调查结果表明，臭娘子入侵显著改变了根际土壤性质和微生物群落，从而影响了生态系统动态和土壤养分供应。然而，进一步研究阐明各种次生代谢物、鉴定微生物群落以及监测受 C. odorata 影响的土壤变化对于有效的生态系统管理至关重要。
