香蕉上的镰孢菌种类及其系统发育关系(英文)

镰孢菌属真菌是香蕉上的重要病原菌,主要引起香蕉枯萎病以及香蕉冠腐病,在我国已明确引起香蕉枯萎病的病原为尖孢镰孢古巴专化型 Fusarium oxysporum f. sp. cubense(FOC)1号和4号生理小种,但是引起香蕉冠腐病的镰孢菌种类还未明确。为了解香蕉上镰孢菌在种间及种内水平上的多样性,2008–2011 年间作者从华南地区不同的水果市场及香蕉果园采集香蕉样品90份,分离得到143株镰孢菌。通过形态学观察及基于 EF-1α基因的系统进化分析鉴定出10种镰孢菌,即F. oxysporum、F. solani、F. camptoceras、F. pallidoroseum、F. stiloides、F. chlamydosporum、F.verticillioides、F. proliferatum、F. concentricum、F. sacchari,以及藤仓赤霉复合种(Gibberella fujikuroi species complex,GFC)中 3 个未定名的类群。轮纹镰孢 F. concentricum 及甘蔗镰孢 F.sacchari 是香蕉果实中最常见种,前菌为我国首次报道,后菌是首次报道与香蕉有关。对从香蕉上分离的藤仓赤霉复合种(GFC)及尖孢镰孢复合种(FOSC)的EF-1α序列进行了系统发育分析,其GFC中的27个菌株组成的单系群可分为7个不同的亚群,分别为 F.verticillioides、F. proliferatum、F. concentricum、F. sacchari 以及3个没有描述过的菌系 Fusarium sp. 1、Fusarium sp.2和 Fusarium sp.3;FOSC中的50个菌株形成2大分枝共12个谱系,分离自我国华南地区的21株尖孢镰孢形成7个谱系,其中 13株已知的香蕉枯萎病病原菌分布在3个谱系中,我国大陆的香蕉枯萎病病原菌菌株与来源于台湾地区及东南亚的菌株亲缘关系较近,FOC1号生理小种的遗传分化大于4号生理小种,FOC 1号生理小种与分离自香蕉果实上的尖孢镰孢菌的亲缘关系比与FOC 4号生理小种的亲缘关系更近。研究结果表明,我国香蕉上存在着丰富的镰孢菌种类,而且种内遗传多样性丰富。     

云南玉溪烤烟土壤真菌的初步研究

对玉溪烤烟连作田和轮作田土壤中的真菌进行分离 ,其真菌数量为 (1.35～ 4.5 6 )× 10 5/ g干土。分离得到的真菌经分类鉴定到属 ,有 4个目 ,7个科 ,45个属 ,优势属为青霉属 (Penicillium)和盾壳霉属 (Coniothyrium) ,其次为芽枝霉属 (Cladosporium)、头孢霉属 (Cephalosporium)、镰孢霉属 (Fusarium)、轮枝孢属 (Verticillium)、柱孢属 (Cylindrocarpon)。     

北细辛内生真菌的分离鉴定及代谢产物的生物活性

采用表面消毒法分别从3种北细辛中分离获得10株形态特征不同的优势内生真菌,经形态学和18S rDNA ITS分子分类学分析鉴定为小丛壳属(Glomerella sp.)、叶点霉属(Phyllosticta sp.)、柄孢壳菌属(Po-dospora sp.)、刺盘孢属(Colletotrichum sp.)和镰孢属(Fusarium sp.)。对北细辛优势内生真菌的发酵产物进行体外抗肿瘤和抗菌活性检测,结果表明:除菌株E3、E4和E10外,其余菌株均有不同程度的抗肿瘤和抗菌活性;镰孢属(Fusarium sp.)菌株E9对A549、MDA-MB-231和PANC-1肿瘤细胞抑制率达75%以上;小丛壳属(Glomerella sp.)菌株E1和叶点霉属(Phyllosticta sp.)菌株E2靶向FabI的抗菌活性较强,抑制率达59%。     

甘肃大葱贮藏期镰孢菌腐烂病病原鉴定

【目的】大葱在贮藏期频繁发生镰孢菌腐烂病,损失严重。明确该病害病原种类对病害防治具有重要意义。【方法】利用组织分离法对采集自甘肃省兰州市(区)蔬菜市场的16份大葱贮藏期镰孢菌腐烂病病样进行病原物的分离、纯化培养,经单孢分离后根据形态学特征,再结合r DNA-ITS、EF-1a(tef)基因序列分析的方法进行鉴定。【结果】共分离得到80株镰孢菌,经鉴定分属3个种,即层出镰孢菌(Fusarium proliferatum)、尖孢镰孢菌(F.oxysporum)和燕麦镰孢菌(F.avenaceum),其中层出镰孢菌为大葱镰孢菌腐烂病的优势致病菌,分离频率为52.50%。对兰州白葱不同部位进行致病性测定,结果表明层出镰孢菌对大葱鳞茎的致病力最强,而燕麦镰孢菌对大葱鳞茎的致病力最弱。【结论】3种镰孢菌作为该病害的病原,属国内首次报道。     

真菌细胞核的一种快速简便染色技术—荧光染色法

本文报导了用荧光染料Hoechst Dye 33258在McIlvaine标准缓冲(pH7.26—7.44)对真菌细胞核染色的技术,这是一种广谱真菌细胞核染色技术,已证明在下列真菌中是有效的:双孢蘑菇(Agaricus bisporus)、向日葵交链孢菌(Alternaria helianthi)、亚麻尖镰孢菌(Fusarium oxysporum f. sp. Iini)、(Penicillium binellure),终极腐霉菌(Pythium ultimum)、立枯丝核菌(Rhizoctonia Solani)、以及酿酒酵母(saccharomyce cerevisiae)。双孢蘑菇,亚麻尖镰孢以及Penicillium binellum的分生孢子细胞核也能很好着色。     

攀枝花苏铁植物内生真菌多样性的初步研究

为研究我国特有孓遗植物攀枝花苏铁(Cycas panzhihuaensis L.Zhou et S.Y.Yang)内生真菌的多样性,分别从原生境和迁移地采集不同部位的组织材料,经培养分离纯化菌株,并进行形态学鉴定和多样性分析.结果显示分离共获得内生真菌438株,其中346株分属3纲、5目、8科、37属,以交链孢属Alternaria sp.、盘多毛孢属Pestalotia sp.、镰孢霉属Fusarium sp.、黑孢霉属Nigrospora sp.为优势属,92株为无孢菌群,研究说明攀枝花苏铁内生真菌具有高度的生物多样性.研究还发现不同采集时间、不同生境多样性相似度较高,但不同组织部位的菌群组成差异比较明显.     

应用PCR-RFLP和巢式PCR检测黄瓜尖镰孢菌

以3株黄瓜尖镰孢菌(Fusarium oxysporum f.sp.cucumarinum)、23株镰孢菌属(Fusariumspp.)真菌和分离自土壤的20株真菌、6株细菌和7株放线菌为材料,采用化学裂解法提取总DNA,进行PCR-RFLP和巢式PCR检测,试验证明PCR-RFLP程序不能完全区分Fusarium属内不同种,而巢式PCR对黄瓜尖镰孢菌具有特异性.运用优化的PCR-RFLP和巢式PCR检测程序对染病黄瓜组织进行了检测,结果表明,两种方法均可在接种发病早期(未显症时)检测出黄瓜枯萎病菌,PCR-RFLP在感病品种接种后3d即可检测到病原菌,而巢式PCR在接种后5d才能检测到病原菌.     

长期连作对大豆根际土壤镰孢菌种群的影响

利用中国科学院海伦农业生态试验站大豆连作长期定位试验区,进行了大豆根际土壤镰孢菌分离鉴定及大豆根腐病致病力检测,结合核酸序列和限制性片段长度多态性(RFLP)的系统发育分析,研究了长期连作(20年)较短期连作(3年)对大豆根际土壤镰孢菌种群密度和结构、致病力及遗传多样性的影响.结果表明： 3年连作大豆根际土壤镰孢菌种群密度为6.0×10⁴ CFU·g^-1,且以强致病力的尖镰孢菌、禾谷镰孢菌、轮枝镰孢菌及中等致病力的腐皮镰孢菌为优势种;连作20年大豆根际土壤镰孢菌种群密度和优势菌的优势度均显著低于3年连作,其中尖镰孢菌、禾谷镰孢菌和腐皮镰孢菌的种群密度仅为3年连作的36%、32%和22%,没有分离到致病力最高的轮枝镰孢菌,而种群多样性和均匀度显著高于3年连作;仅分离自20年连作土壤的三线镰孢菌、砖红镰孢菌及燕麦镰孢菌均为非致病菌种,且与强致病力镰孢菌种在基于转录间隔区(ITS)和转录延长因子(EF-1α)序列的聚类分析中显示了系统进化亲缘关系的差异性.因此,大豆20年连作会导致根际土壤镰孢菌种群生长受抑制、使其种群结构和遗传多样性发生改变,同时降低大豆根腐病菌种群致病力.     

串珠镰刀菌和尖孢镰刀菌对玉蜀黍苗期侵染的接种试验

以土壤接种的方法测定了串珠镰刀菌(Fusarium moniliforme Sheld.) 3个菌株和尖孢镰刀菌(Fusarium oxysporum Schl．)9个菌株对玉蜀黍幼苗的侵染力。结果表明在试验菌株中存在强、中等、不稳定、弱至无四种致病力类型。串珠镰刀菌中的NF2109(分离白玉蜀黍杆腐病株)和哈医143(分离自玉蜀黍种粒),尖孢镰刀菌中的NF1800(分离自香蕉果柄)和NF109(分离自松林土壤)属于强致病力类型。尖孢镰刀菌中的NF033(分离自玉蜀黍种粒)、NF245(分离自苹果烂根)、哈医142(分离自玉蜀黍种粒)属于中等强度类型。其余5个试验菌株有2个不稳定,3个呈弱或无致病力类世。叙述了这些菌引起的玉米苗枯的症状,并认为对玉蜀黍苗期的侵染,串珠镰刀菌的危在较之尖孢镰刀菌为大,并就试验菌林的致病力讨论了有关尖孢镰刀菌号化型问题。     

三江平原地区大豆根腐病病株上镰孢菌的分离鉴定

为了明确引起三江平原地区大豆根腐病的镰孢菌(Fusarium)种类及优势种群,对该地区大豆根腐病样本进行了采集。通过组织分离和形态学鉴定,共鉴定出6种镰孢菌,分别为木贼镰孢(F.equiseti)、尖孢镰孢(F.oxysporum)、芬芳镰孢(F.redolens)、半裸镰孢(F.semitectum)、腐皮镰孢(F.solani)和拟轮枝镰孢(F.verticillioides)。其中尖孢镰孢(F.oxysporum)的分离频率最高,达16.67%。对6种镰孢菌的形态学特征进行了描述。     

New agricultural practices in the Loess Plateau of China do not reduce colonisation by arbuscular mycorrhizal or root invading fungi and do not carry a yield penalty

Agricultural practices aimed to reduce soil erosion and improve crop yield have been suggested to influence the activity of arbuscular mycorrhizal (AM) and root pathogenic fungi. We conducted a two-year field survey to investigate the effect of recently introduced agricultural practices on crop yield, AM colonisation and percentage isolation of root-invading fungi on the heavily eroded Loess Plateau of China. A rotation of maize (Zea mays L.), winter wheat (Triticum aestivum L.) and soybean (Glycine max L.) replaced monoculture of winter wheat. No-tillage (NT), and return of previous crop residues to the field in tilled (CTR) and non-tilled (NTR) systems replaced conventional tillage (CT). Yield, biomass and phosphorus content of the crops showed similar trends. Residue application increased yields of maize and soybean independent of tillage treatment in 2004, but only under CT in 2005. CT slightly increased maize yield. Neither residue application nor tillage treatment affected yield of wheat. None of the treatments influenced total percent isolation of root-invading fungi from wheat roots. The increase of some individual pathogenic fungi in NT did not translate into reduction of yield by disease. Importantly, the recommended practices did not have a penalty on yield while maintaining high levels of AM colonisation.     

黄土高原苜蓿-粮食作物轮作下土壤细菌群落特征和生态功能预测

为揭示多年种植苜蓿后轮作不同作物对黄绵土细菌群落的影响,本研究通过布设在黄土高原雨养农业区的长期定位试验,采用16S rRNA基因高通量测序技术和PICRUSt方法探究苜蓿(LC)、苜蓿-休闲-小麦(L_FW)、苜蓿-休闲-玉米(L_FC)、苜蓿-马铃薯(LP)与苜蓿-谷子(LM)对土壤细菌群落结构和多样性的影响,并利用PICRUSt法预测了其生态功能。结果表明: 半干旱区黄绵土细菌优势门为放线菌门(20.3%～32.0%)、变形菌门(19.2%～23.0%)、酸杆菌门(12.4%～14.2%)和绿弯菌门(11.0%～12.7%),其中苜蓿翻耕轮作玉米土壤优势细菌属为芽孢杆菌属(1.9%),其余处理土壤细菌优势属均为假节杆菌属(2.5%)。多年生苜蓿翻耕轮作不同粮食作物后显著降低了放线菌门相对丰度,但显著提高了绿弯菌门和厚壁菌门的相对丰度。冗余分析表明,影响苜蓿及轮作作物土壤细菌群落结构的主要环境因子是硝态氮、铵态氮和全氮。PICRUSt功能预测结果表明,新陈代谢(78.6%～79.1%)为黄绵土细菌群落的主要功能,苜蓿翻耕轮作作物显著降低了土壤细菌碳水化合物代谢功能基因丰度,但明显提高了土壤细菌辅助因子和维生素代谢、神经退行性疾病、免疫系统等功能基因丰度。综上,多年生苜蓿翻耕轮作一年生作物改变了土壤细菌群落结构和生态功能,该结果可为黄绵土细菌群落演替特征的探索和苜蓿适宜后茬作物的确定提供理论参考。     

Influence of diet and monensin on development of anaerobic fungi in the rumen, duodenum, cecum, and feces of cows

Three cows with fistulated rumens, duodenums, and ceca were fed five different diets: lucerne hay, lucerne hay plus whey (40:60), lucerne hay plus beets (50:50), corn silage plus monensin (40 ppm [40 g/kg] of dry matter intake), and lucerne hay plus monensin (80 ppm of dry matter intake). The fungal population was observed in the rumen, duodenum, cecum, and rectum and varied with diet; it was most abundant with lucerne hay alone and with corn silage plus monensin. The proportion of particles colonized by fungi in the duodenum, the cecum, and feces was measured by microscopic observation and varied from 5 to 50%, depending on the diet. The further sporangia attached to the plant particles were from the rumen, the more likely they were to be devoid of spores. Results confirmed the influence of diet on the development of the ruminal fungal population and showed that monensin does not eliminate these microorganisms. They also confirmed the presence of anaerobic fungi in the ruminant intestine. It is likely that anaerobic fungi leave the rumen attached to plant particles. However, large colonies of nonrhizoidal-type fungi were observed in cecum samples and in feces; at these sites, environmental conditions are perhaps more favorable for this type of fungus than they are in the rumen.     

Fungi Associated with Root Rot of Winter Wheat in Alabama

Winter wheat plants were sampled during the spring and autumn to identify fungi associated with root rot in Alabama. Samples were taken from 61 fields in the major wheat-producing areas of the state; 179 fungi were isolated, identified, and tested for pathogenicity. Of the fungi identified, 46 (26%) were Gaeumannomyces graminis var. tritici , 37 (21%) were Cochtiobolus sativus , and 55 (31%) were Fusarium species of which 37 (21%) were Fusarium oxysporum . Other fungi identified that were pathogenic on wheat were Rhizoctonia solani, Sderotium rolfsii , and Pythium spp. G. g. var. tritier was the main pathogen associated with diseased root and lower stem tissue of wheat in Albama.     

Influence of diet and monensin on development of anaerobic fungi in the rumen, duodenum, cecum, and feces of cows.

Three cows with fistulated rumens, duodenums, and ceca were fed five different diets: lucerne hay, lucerne hay plus whey (40:60), lucerne hay plus beets (50:50), corn silage plus monensin (40 ppm [40 g/kg] of dry matter intake), and lucerne hay plus monensin (80 ppm of dry matter intake). The fungal population was observed in the rumen, duodenum, cecum, and rectum and varied with diet; it was most abundant with lucerne hay alone and with corn silage plus monensin. The proportion of particles colonized by fungi in the duodenum, the cecum, and feces was measured by microscopic observation and varied from 5 to 50%, depending on the diet. The further sporangia attached to the plant particles were from the rumen, the more likely they were to be devoid of spores. Results confirmed the influence of diet on the development of the ruminal fungal population and showed that monensin does not eliminate these microorganisms. They also confirmed the presence of anaerobic fungi in the ruminant intestine. It is likely that anaerobic fungi leave the rumen attached to plant particles. However, large colonies of nonrhizoidal-type fungi were observed in cecum samples and in feces; at these sites, environmental conditions are perhaps more favorable for this type of fungus than they are in the rumen.     

黄土高原苜蓿-冬小麦轮作系统土壤水分时空动态及产量响应

2 0 0 1～ 2 0 0 3年在甘肃庆阳黄土高原连续 3 a研究了紫花苜蓿 -冬小麦轮作系统中土壤 0～ 3 0 0 cm剖面水分动态特征 ,作物产量及其含 N量。处理包括 4龄苜蓿草地 (L C)、4龄苜蓿草地后茬持续休闲 (L F)、4龄苜蓿草地休闲 4个月后种植冬小麦(L Fl W) ,和 4龄苜蓿草地休闲 1个月后种植冬小麦 (L Fs W)。结果表明 ,种植 4a苜蓿后春季翻挖实施休闲至冬小麦播种(L Fl W)的 4个月期间 ,降雨的入渗深度为 150 cm,而苜蓿秋季翻挖休闲至小麦播种 (L Fs W)的一个月间 ,降雨在土壤内的入渗深度为 90 cm,不同休闲长度对头茬冬小麦土壤 0～ 90 cm水分贮存量无显著影响 ,亦不影响头茬冬小麦的出苗和出苗数。苜蓿后茬完全休闲 (L F)一个生长季后 ,60～ 90 cm土壤水分含量达田间最大重力持水量 (Drainage U pper L imit DU L )的 93 % ,0～ 3 0 0cm剖面土壤贮水量达 670 mm ,是剖面田间最大重力持水量 (DUL )的 78% ;L Fl W和 L Fs W处理下头茬小麦籽粒产量之间差异显著 (P<0 .0 5) ,收获指数和千粒重等指数无显著差异 ;L Fl W和 L Fs W处理中获得的二茬小麦产量无显著差异 ;连续种植苜蓿与种植小麦有接近的生物量 ,但苜蓿地植物总 N的输出量较小麦田高 2～ 3倍。由于黄土高原降雨变率大 ,因此预测土壤含水量动态有     

Influence of soil heterogeneity on water regime and yields of lucerne,sugar beet and wheat

Lucerne plants in the first crop year as well as plants of spring wheat from different sites of the respective experimental plots showed differences in sap exudation from detopped roots or from stumps of the main shoots, reflecting differences in properties of the soil profile. The differences in sap exudation were observed at a time when the plants did not show any visible differences in water availability. Differences in the water potential deficit of the leaf blades of lucerne plants in the second crop year and of sugar beet plants, related to differences in soil profile properties, were observed in another series of experiments. Sugar beet plants showed a higher physiological lability than lucerne plants. The sites characterized by unfavourable plant-water-relations usually gave lower yields. The coefficients of variability for the yields of lucerne fresh matter from irrigated plots were three times lower than those for yields from plots without irrigation, influenced by soil heterogeneity.     

黄土丘陵半干旱区不同作物生态效能研究

深入研究特定生态环境条件下不同作物生产力及其生态效能,对于合理调控农田生态系统,探讨提高系统生产力途径具有重要意义。60年代以来,在国际生物学计划(IBP)的影响下,美国、日本、菲葎宾等国先后进行了小麦、水稻、大豆等作物农田生态效能研究。我国于“六·五”期间分别在南方稻区、黄淮海平原以及北方灌区等不同农业区开展了多种作物种植制度生产力问题研究,并取得重     

The intake and digestion of maize silage-based diets by dairy cows and sheep

Six lactating cows, 6 dry cows and 6 wether sheep were fed ad libitum on diets of maize silage, maize silage plus lucerne, or maize silage plus lucerne plus wheat. Faeces and urine collections allowed for the determination of digestibility of dry matter, organic matter and nitrogen, and balances of nitrogen and water.

Voluntary feed intakes were highest and digestibility values were lowest in lactating cows. The addition of lucerne reduced organic matter digestibility in dry cows, but not in lactating cows or sheep. The addition of wheat decreased intake in dry cows and sheep, but not in lactating cows. Production of milk, protein, solids-not-fat and total solids increased with dietary quality, but there was a depression in milk fat content as a result of wheat supplementation.

The ranking of the 3 diets on the basis of feed intake differed with each class of livestock, but lactating cows and sheep gave the same ranking on the basis of organic matter digestibility.     

The Influence of the Application of Mineral Fertilizers with the Biopreparation Supresivit ( Trichoderma Harzianum ) on the Health and the Yield of Different Crops

The biopreparation Supresivit based on spores from the fungus Trichoderma harzianum was applied as a dressing mixed with mineral fertilizers: NPK, LAV (ammonium nitrate with limestone) and DASA (ammonium nitrate and ammonium sulphate). Our experimental plots with spring barley, winter wheat, winter oil rape, maize and potatoes were fertilized with the mixtures of the biopreparation (1 g, 0.5 g and 0.1 g per 1 kg of fertilizer). There were two check variants, the first variant without any fertilization and without biopreparation, the second with fertilizer and without biopreparation. We observed the infestation of plants with pathogenic fungi and yield parameters. In our experiments it was indicated that Trichoderma harzianum suppresses pathogenic fungi at the concentration 0,5 g of Supresivit per 1 kg of the fertilizer and higher ones. The plants from treated plots had lower infestation - decreasing about 5-15% superficial infestation: tan spot of barley - yellow leaf spot on cereals and leaf blotch of barley, winter wheat - leaf spot of wheat, tan spot of wheat, take-all etc., winter oil-seed rape - black leg and collar rot, potatoes - blight fungus etc. Simultaneously the effect on higher yields was observed.