Long-term effects of eight soil health treatments to control plant-parasitic nematodes and Verticillium dahliae in agro-ecosystems

There is an urgent need to test and develop sustainable methods for management of soil pathogens, such as the root-lesion nematode Pratylenchus penetrans and the soil fungus Verticillium dahliae. Ultimately this should be investigated with a multidisciplinary approach, with long-term measurements of biological and chemical parameters and their final impact on crop yield under field conditions. The present study focusses on eight soil health treatments (compost, chitin, marigold, grass–clover, biofumigation, anearobic soil disinfestation, a physical control method and a combination of marigold, compost and chitin) and two control treatments (a chemical control with 300 L/ha Metam sodium and un untreated control). These 10 treatments were studied for their effects on soil chemical quality, soil pathogens and their impact on the yield of potato, lily and carrots during 6 years. The present study did demonstrate that in comparison to chemical control, additions of chitin, anaerobic soil disinfestation and marigold are already excellent alternatives for the control of plant-parasitic nematodes and V. dahliae. We also demonstrated that grass–clover, biofumigation, Cultivit and compost are not effective alternatives for chemical control yet and further development is needed. All treatments caused a yield increase in comparison with the control. The biggest increases of more than 60% were found for the treatments with chitin. Furthermore it was demonstrated that these yield increases were probably less influenced by changes in chemical soil properties, but the consequence of changes in the soil biota, in this case especially the effective control of P. penetrans and V. dahliae. Furthermore it has been demonstrated that most of these soil health treatments could already be implemented in an arable crop rotation and probably adapted for many areas of the world where other alternatives, such as solarisation or soil flooding, are not feasible or too risky.     

竹材的防霉试验研究报告

本研究根据竹材防霉效力值,试验五种配方对竹材的防霉效果。结果:0.1％MBT和0.5％DP的防霉效果不次于2.5％BP(主剂为Na-PCP),尤其是MBT,使用浓度较低,高效,有可能代替氯酚类防霉剂;0.5％苯菌灵和3.0％季胺盐化合物的防霉效果较差,建议可用作竹材的短期防霉。     

外生菌根真菌纯培养中生理活性物质代谢的研究

随着外生菌根研究的不断深入,越来越多的菌根工作者开始注意到了外生菌根真菌生理活性物质研究的重要价值。T.Santoro et al.,G.N.Krywolap et al.,D.H Marx等先后研究了外生菌根菌在各种培养条件下产生拮抗活性物质及这些拮抗物的理化性质和生物学功能,证明了外生菌根具有生物防治效应的部分原因是由于真菌抗生素的分泌。80年代以来,发现外生菌根及其真菌产生的植物激素在形成菌根及促进寄主植物生长方面起重要作用。如J.H.Graham et al.等先后研究了外生菌根菌产生某些     

一种大型野生真菌子实体解剖学和可食性研究

研究了一种大型野生真菌子实体的解剖学特征和子实体的可食性,结果表明:该野生真菌属蘑菇科环柄菇属红顶环柄菇;子实层主要由担子和侧囊状体组成,担子顶部着生4个担孢子,孢子印白色,菌髓中菌丝排列不规则,属混淆不规则型,丝状菌肉;子实体提取液对果蝇生长发育具有促进作用;品尝试验,未出现不良反应。     

Fungal/bacterial ratios in grasslands with contrasting nitrogen management

It is frequently hypothesised that high soil fungal/bacterial ratios are indicative for more sustainable agricultural systems. Increased F/B ratios have been reported in extensively managed grasslands. To determine the shifts in fungal/bacterial biomass ratio as influenced by grassland management and to find relations with nitrogen leaching potential, we sampled a two-year-old field experiment at an organic experimental farm in the eastern part of The Netherlands. The effect of crop (grass and grass-clover), N application rate (0, 40, 80, ) and manure type (no manure, farm yard manure and slurry) on the F/B ratio within three growing seasons was tested, as well as relations with soil and crop characteristics, nitrate leaching and partial N balance. Biomass of fungi and bacteria was calculated after direct counts using epifluorescence microscopy. Fungal and bacterial biomass and the F/B ratio were higher in grass than in grass-clover. The F/B ratio decreased with increasing N application rate and multiple regression analysis revealed a negative relationship with pH. Bacterial activity (measured as incorporation of [³H]thymidine and [¹⁴C]leucine into bacterial DNA and proteins) showed the exact opposite: an increase with N application rate and pH. Leaching increased with N application rate and was higher in grass-clover than in grass. Partial N balance was more positive at a higher N application rate and showed an inverse relationship with fungal biomass and F/B ratio. We conclude that the fungal/bacterial biomass ratio quickly responded to changes in management. Grasslands with higher N input showed lower F/B ratios. Grass-clover had a smaller fungal biomass and higher N leaching than grass. In general, a higher fungal biomass indicated a lower nitrogen leaching and a more negative partial N balance (or smaller N surplus), but more observations are needed to confirm the relationship between F/B ratio and sustainability.     

Bioaccumulation of gold in macrofungi and ectomycorrhizae from the vicinity of the Mokrsko gold deposit, Czech Republic

Samples of macrofungi collected in the vicinity of the Mokrsko gold deposit were analyzed for Au by INAA and ICP-MS. Ectomycorrhizal fungi yielded from 0.88 to 564 μg kg⁻¹ Au (dry weight) in 79 samples. Saprobic fungi (75 samples) from the same locations yielded significantly higher concentrations: 3-7739 μg kg⁻¹ Au (dry weight), with the highest contents in Lycoperdon perlatum. These are the highest recorded concentrations of Au in naturally-occurring fungi/vascular plants. Concentrations of Au in ectomycorrhizae were approximately 4-10 times higher than those in fine roots. It appears that saprobic fungi, namely several terrestrial saprobes of the genera Agaricus and Lycoperdon, are more efficient than ectomycorrhizal fungi at taking up Au, probably assisted by other microbiota and/or by a range of naturally-occurring compounds that have yet to be identified. The present data demonstrate that macrofungi are involved in the biogeochemical cycling of Au.     

小麦多聚半乳糖醛酸酶抑制蛋白对几种病原真菌抑制作用的研究

 本文以单子叶植物小麦(Triticum aestivum L.)的黄化苗为材料,用小麦品种SW89-2589的多聚半乳糖醛酸酶抑制蛋白(PGIP)作用4种病原真菌,发现小麦PGIP对几种病原真菌分泌的内切多聚半乳糖醛酸酶(endo-PG)有抑制作用,4种病原真菌endo-PG被抑制程度的大小关系依次为Pyriaclaria oryzae、Sclerotinia sclerotiorium、Fusarium graminearum、Exserohilum turcicum;小麦PGIP对4种病原真菌生长有抑制作用,并且能引起小麦禾谷镰刀菌和玉米大斑病菌生长异常。     

多效降温反季节菇田栽培食用菌效果对比试验

针对广东省漫长的高温季节进行了人工低能耗降温试验，采用超高压微量喷雾、山水沟灌、棚顶滴流、增设隔热层等多效降温措施，使大棚式菇田内外温差在高温天气下达到5～7℃，使杏鲍菇、香菇、猴头菇、秀珍菇等中低温型食用菌品种可以在夏季正常出菇。为非空调制冷条件下延长广东的食用菌生产季节提供了有效的方法，其低廉的能耗成本为农村的推广创造了条件。     

Pestalotiopsis kenyana是侵染蓝莓的一个新纪录种

通过与蓝莓上已报道的类拟盘致病菌系统发育对比,发现有5株类拟盘菌株聚集形成一个相对独立分支,表明这5株菌可能属于1个危害蓝莓的新纪录种;为确定该危害蓝莓的类拟盘多毛孢种类,采用三层次系统发育比较法和传统形态鉴定法对其进行鉴定,结果表明5株病原菌均属于Pestalotiopsis kenyana,分生孢子大小为(20.7~28.8)μm×(4.7~7.2)μm,中间三色细胞同色,长为13.2μm~18.0μm,具2~3根顶端附属丝,1根基部附属丝。     

Microbial biomass in soils of Russia under long-term management practices

 Non-tilled and tilled plots on a spodosol (C_org 0.65–1.70%; pH 4.1–4.5) and a mollisol (C_org 3.02–3.13%, pH 4.9–5.3), located in the European region of Russia, were investigated to determine variances in soil microbial biomass and microbial community composition. Continuous, long-term management practices, including tillage and treatment with inorganic fertilizers or manure, were used on the spodosol (39 years) and mollisol (22 years). Total microbial biomass (C_mic), estimated by the substrate-induced respiration (SIR) method, and total fungal hyphae length (membrane filter technique) were determined seasonally over a 3-year period. Long-term soil management practices (primarily tillage and fertilizer application) led to decreases in total microbial biomass (80–85% lower in spodosol and 20–55% lower in mollisol), decreases in the contribution of C_mic to C_org (2.3- to 3.5-fold lower in spodosol and 1.2- to 2.3-fold lower in mollisol), and 50–87% decreases in total fungal hyphae length compared to non-tilled control plots. The contribution of fungi to total SIR in virgin mollisol and fallow spodosol plots was approximately 30%. However, the contribution of fungi to SIR was approximately two times greater in tilled spodosol plots compared to a fallow plot. In contrast, the contribution of fungi to SIR in tilled plots of mollisol was less (1.4–4.7 times) than for a virgin plot. In summary, long-term soil management practices such as tillage and treatment with organic or inorganic fertilizers are important determinants of soil microbial biomass and the contribution of fungi to total SIR. Received: 28 April 1998