MES [2-(N-morpholine)-ethane sulphonic acid] buffer promotes the growth of external hyphae of the arbuscular mycorrhizal fungus Glomus intraradices in an alkaline sand

In this work we investigated the hypothesis, suggested by unpublished experiments carried out previously, that application of MES [2-(N-morpholino)-ethane sulphonic acid] buffer to the substrate of plants hosting the arbuscular mycorrhizal fungus Glomus intraradices might favour the growth of external hyphae. The substrate of Trifolium pratense plants, with or without G. intraradices inoculum, was treated twice weekly, between weeks 5 and 11 of growth, plant with distilled water, P-supplemented 10% Hewitt nutrient solution (H+P), 51mM in H+P or 1mM TRIS-HCl in H+P. MES buffer increased the length of external G. intraradices hyphae and the density of propagules in the substrate, but plant growth was not affected. Although both TRIS-HCl and MES caused substrate pH to fall (from 8.51 to 7.35 and 7.17, respectively), only MES induced a significant increase in external hypha length. We conclude that the effect of MES on external hypha length was not due to plant growth or to substrate pH per se. Received: 10 March 1996     

Adhesive hyphae ofArthrobotrys oligospora: an ultrastructural study

Electron microscopic studies of the interaction of second-stage juveniles ofMeloidogyne hapla andArthrobotrys oligospora (CBS 289.82) strongly suggest that hyphae attachment to nematodes was mediated by a 0.1m thick layer matrix between the fungus and prey after contact with the nematode cuticle. The amorphous electron opaque matrix was irregularly distributed over the fungal surface, in some cases covering only the side attached to the nematode. Serial sections of adhesive hyphae showed that the extracellular matrix spread from the exact site of capture. A matrix with this thickness was never observed in the absence of nematodes.     

亚侧耳菌丝生长的最适pH值和温度的测定

该文研究了pH值和温度两种因素对亚侧耳菌丝生长的影响,试图求出最适宜亚侧耳菌丝生长的pH值和温度.研究中pH值为5,6,7,8,9,温度为22℃,24℃,26℃,28℃,30℃.试验结果表明:以菌丝的日增长长度为统计指标进行两因素方差分析,再通过对菌丝增长长度的平均值进行多重比较,最后得出pH6为亚侧耳菌丝生长的最佳酸碱度,26～28℃均适宜亚侧耳菌丝的生长,且亚侧耳菌丝生长的最佳组合为温度26℃、pH6.     

醋酸钠及复配4种矿物质对草菇菌丝生物量的影响

通过测定菌丝DNA含量,检测不同浓度梯度醋酸钠对草菇菌丝生物量的影响,结果表明,随着醋酸钠浓度的升高,菌丝生物量呈线性增加,当达到0.7 g·L^-1时,生物量达到一个高峰值,DNA的含量为468.9±4.10 μg·g^-1,极显著地高于对照组,随着醋酸钠浓度继续增加到0.9 g·L^-1和1.1 g·L^-1时,生物量则呈减少的趋势,但均比对照的生物量高,说明适宜的醋酸钠浓度能极显著地增加草菇菌丝生物量。在筛选出最佳醋酸钠浓度(0.7 g·L^-1)的基础上,进一步复配Cu、Zn、K、Mn元素,以醋酸钠为对照,比较复配微量元素及同一微量元素不同浓度对草菇菌丝生物量的影响。结果显示,添加矿物质K和Cu元素效果较好,各浓度均能使菌丝生物量有所增加,其中添加8 g·L^-1 KH₂PO₄处理的菌丝生物量比对照的高84.32%(P<0.05);添加0.04 g·L^-1 CuSO₄处理的菌丝生物量比对照高73.19%,达到5%显著水平;ZnSO₄添加量为0.25 g·L^-1和0.20 g·L^-1两处理的菌丝生物量分别比对照提高42.69%和20.34%;添加0.35 g·L^-1 MnSO₄处理的菌丝生物量比对照提高25.23%以上。Zn和Mn元素的各浓度处理与对照的菌丝体生物量无显著差异。     

共生法培养外生菌根菌菌丝体

首次报道外生菌根菌的共生培养法初步研究了一个较好的外生菌根菌菌丝体培养方法，即将宿主的愈伤组织与外生菌根共同培养，可以明显地促进真菌菌丝的萌发和生长。愈伤组织匀浆液也可促进菌丝体早期生长。     

Chalastospora gossypii in a Maine Coon cat: case report and literature review

A 15-y-old castrated male Maine Coon cat was evaluated for an ulcerated soft tissue mass on the right hindlimb that had been observed for 4 mo and had grown rapidly. A 3 × 3 cm soft, raised, amorphous, and ulcerated subcutaneous mass was observed on the lateral right metatarsus. In-house cytology via fine-needle aspiration was nondiagnostic. Incisional biopsy of the mass and further staging was declined, and amputation was elected. The amputated limb was submitted for histopathology, which revealed severe chronic nodular granulomatous dermatitis and multifocal granulomatous popliteal lymphadenitis with large numbers of intralesional fungal hyphae. Fungal PCR and sequencing on formalin-fixed, paraffin-embedded tissue identified Chalastospora gossypii. No adjunctive therapy was elected at the time. The patient has done well clinically 1 y post-operatively. C. gossypii is a rare microfungus found worldwide and is considered a minor pathogen of several plants. To our knowledge, infection by this fungus has not been reported previously in veterinary species. Features in our case are comparable to other mycotic infections. Nodular granulomatous mycotic dermatitis and cellulitis, although uncommon, should be a differential for soft tissue masses in veterinary species; C. gossypii is a novel isolate.     

根间菌丝桥对三叶草生长及磷营养状况的影响

用五室方法研究了不同收获期三叶草根间菌丝桥对受体植株生长及体内磷营养状况的影响。结果表明三叶草根问菌丝矫形成以后,受体三叶草的生物量和体内磷的含量和浓度均有所增加,且与对照处理间的差异随接种时间的延长表现的更为明显。     

姬松茸菌丝及担孢子核观察

用荧光染色法观察姬松茸菌丝体和担孢子的核,用扫描电镜观察姬松茸担孢子着生情况。结果表明：姬松茸菌丝体为多核,未见到锁状联合;姬松茸担孢子56．3％为双核,17．6％为单核;姬松茸每个担子上着生4个或3个担孢子。     

核转运蛋白SsKapM涉及调控甘蔗鞭孢堆黑粉菌的菌丝生长

 核转运蛋白是真核生物中负责大分子物质进出核孔的重要载体,承担着维持正常生命活动的任务。本研究通过序列同源比对鉴定了甘蔗鞭孢堆黑粉菌核转运蛋白编码基因,根据注释命名为SsKapM。使用同源重组方法对SsKapM进行敲除后,发现ΔSsKapM突变体担孢子的生长速率、适宜的生长温度、有性配合/菌丝生长等方面均发生改变。研究中还发现SsKapM缺失会导致双核菌丝体对高浓度磷酸盐敏感性下降。同时,通过转录组数据分析探究SsKapM的功能机制。结果表明SsKapM调控热激反应、磷酸盐信号与转运通路等基因的表达。这一发现将为甘蔗鞭孢堆黑粉菌的防治提供新的思路。