Loffredo Elisabetta, Berloco Mariagrazia, Senesi Nicola
Dipartimento di Biologia e Chimica Agroforestale ed Ambientale, University of Bari, Via Amendola 165/A, 70126 Bari, Italy.
Ecotoxicol Environ Saf. 2008 Mar;69(3):350-7. doi: 10.1016/j.ecoenv.2007.11.005. Epub 2008 Jan 4.
The regulation capacity of four humic substance (HS) samples, a soil humic acid (HA) and two HAs and one fulvic acid (FA) isolated from a composting substrate, was evaluated at two concentrations on the growth in vitro of one plant pathogenic, Sclerotinia sclerotiorum, and two antagonistic, Trichoderma viride and T. harzianum, soil-borne fungi. The presence of any HS sample in the growing medium, especially those from the composting substrate, caused a relevant inhibition of the mycelial growth of S. sclerotiorum and a marked stimulation of sclerotial formation that was exhibited as early appearance and numerical increase. On the contrary, the same HS treatments generally did not inhibit the growth of the two Trichoderma species. In particular, T. viride was significantly stimulated by any HS sample at any concentration, with the only exception of HA from fresh-composting substrate, whereas T. harzianum appeared to be stimulated only slightly or not significantly influenced. Only S. sclerotiorum showed evident high correlations of both the extent of the inhibitory action on mycelial growth and the final number of sclerotia with some chemical and functional properties of HS, such as total acidity, COOH group content, and elemental composition.
评估了四种腐殖质（HS）样品、一种土壤腐殖酸（HA）以及从堆肥基质中分离出的两种HA和一种富里酸（FA）在两种浓度下对一种植物病原真菌核盘菌（Sclerotinia sclerotiorum）以及两种拮抗菌绿色木霉（Trichoderma viride）和哈茨木霉（T. harzianum）这三种土传真菌体外生长的调控能力。生长培养基中存在任何HS样品，尤其是来自堆肥基质的样品，都会对核盘菌的菌丝生长产生显著抑制，并显著刺激菌核形成，表现为菌核出现早且数量增加。相反，相同的HS处理通常不会抑制两种木霉菌种的生长。具体而言，除了来自新鲜堆肥基质的HA外，任何浓度的任何HS样品都会显著刺激绿色木霉的生长，而哈茨木霉似乎仅受到轻微刺激或无显著影响。只有核盘菌对菌丝生长的抑制作用程度和菌核最终数量与HS的某些化学和功能特性（如总酸度、COOH基团含量和元素组成）表现出明显的高度相关性。
