Ndeko Adrien Byamungu, Diedhiou Abdala Gamby, Founoune-Mboup Hassna, Chuma Géant Basimine, Mugumaarhahama Yannick, Diouf Diegane, Fall Saliou, Mushagalusa Gustave Nachigera, Kane Aboubacry
Department of Crop Production, Faculty of Agriculture and Environmental Sciences, Université Evangélique en Afrique (UEA), Bukavu, Democratic Republic of the Congo.
Département de Biologie Végétale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop (UCAD), Dakar, Senegal.
PLoS One. 2024 Dec 13;19(12):e0312581. doi: 10.1371/journal.pone.0312581. eCollection 2024.
Rhizosphere microorganisms, particularly arbuscular mycorrhizal fungi (AMF), play a vital role in enhancing sustainable maize production. However, uncertainty persist regarding the influence of climate variables and soil properties on mycorrhizal colonization (MC) of maize and the abundance of AM fungal spores in the field. This study aimed to explore the environmental factors such as site climate variables, soil physicochemical properties and topography and vegetation variable, affecting the natural MC of maize and the density of AMF spores. The study hypothesizes that natural maize mycorrhizal colonization and AMF spore density vary significantly across different sites and agroecological zones. It further posits that climatic and edaphic variables predominantly explain the observed variation in mycorrhizal parameters. To assess the impact of these factors, a field study was conducted in 32 sites across three territories in the province of South Kivu, namely Kabare, Walungu, and Uvira. Rhizospheric soil and maize roots were collected from different sites. Maize MC varied significantly among sites, with Kabare and Walungu showing high colonization rates (52.1% and 44.7%, respectively) compared to Uvira (26.40%). Meanwhile, spore density was significantly higher in Uvira (1331.7 spores g-1 soil) than in Kabare (518.9 spores g-1 soil) and Walungu (468.58 spores g-1 soil). Correlation analysis indicated that maize MC was influenced by site climate and soil properties. The PLS-SEM model demonstrated that 76.5% (R2) of the total variance in maize root MC was explained by climatic variables and soil chemical properties. Compared to soil chemical properties, climate characteristics had a more pronounced impact on maize MC. Maize MC was inversely correlated with temperature, C and available P content, while being directly and positively correlated with altitude, rainfall, and base saturation rate. Furthermore, 68.5% (R2) of the spore density variability of AMF was explained by climatic variables and soil physical properties. Spore density was inversely correlated with sand and clay content, field capacity, rainfall, and altitude, while being positively correlated with temperature. The results of this study indicate that climatic conditions exert a more pronounced influence on the mycorrhizal colonization of maize and the density of AMF spores than soil characteristics.
根际微生物，尤其是丛枝菌根真菌（AMF），在提高玉米可持续产量方面发挥着至关重要的作用。然而，气候变量和土壤性质对玉米菌根定殖（MC）及田间AM真菌孢子丰度的影响仍存在不确定性。本研究旨在探究影响玉米自然MC和AMF孢子密度的环境因素，如站点气候变量、土壤理化性质以及地形和植被变量。该研究假设，不同站点和农业生态区的玉米自然菌根定殖和AMF孢子密度存在显著差异。研究进一步认为，气候和土壤变量是观察到的菌根参数变化的主要解释因素。为评估这些因素的影响，在南基伍省的三个地区（卡巴雷、瓦伦古和乌维拉）的32个站点开展了田间研究。从不同站点采集根际土壤和玉米根系。不同站点间玉米MC差异显著，与乌维拉（26.40%）相比，卡巴雷和瓦伦古的定殖率较高（分别为52.1%和44.7%）。同时，乌维拉的孢子密度（1331.7个孢子/克土壤）显著高于卡巴雷（518.9个孢子/克土壤）和瓦伦古（468.58个孢子/克土壤）。相关性分析表明，玉米MC受站点气候和土壤性质影响。偏最小二乘结构方程模型（PLS - SEM）表明，气候变量和土壤化学性质解释了玉米根MC总方差的76.5%（R2）。与土壤化学性质相比，气候特征对玉米MC的影响更为显著。玉米MC与温度、碳和有效磷含量呈负相关，而与海拔、降雨量和碱基饱和度呈正相关。此外，气候变量和土壤物理性质解释了AMF孢子密度变异性的68.5%（R2）。孢子密度与砂和粘土含量、田间持水量、降雨量和海拔呈负相关，与温度呈正相关。本研究结果表明，气候条件对玉米菌根定殖和AMF孢子密度的影响比土壤特征更为显著。
