西南地区玉米纹枯病病菌融合群鉴定和UP-PCR分析

为明确西南地区玉米纹枯病病菌组成结构,从西南地区(四川、贵州、云南和重庆)玉米纹枯病样上分离获得285个疑似丝核菌菌株,根据培养性状、菌丝形态和细胞核染色对其进行鉴定,通过载玻片配对培养法对鉴定出的菌株进行菌丝融合群鉴定,并采用UP-PCR方法从各融合群中选取代表性菌株进行遗传变异分析。结果显示,供试疑似菌株中共鉴定出253个丝核菌,分别为224株立枯丝核菌Rhizoctonia solani和29株玉蜀黍丝核菌R.zeae。立枯丝核菌包括5个融合群,其中AG1-ⅠA共201株,出现频率为79.4%;AG1-ⅠB共2株,出现频率为0.8%;AG2-2ⅢB共3株,出现频率为1.2%;AG4-HGⅠ共10株,出现频率为3.9%;AG-5共8株,出现频率为3.2%。29株玉蜀黍丝核菌融合群均为WAG-Z,出现频率为11.5%。遗传变异分析中,当相似系数为0.78时,按照出现频率从立枯丝核菌和玉蜀黍丝核菌选取的不同融合群的20株菌株被划分为6个类群,与菌丝融合分析结果完全吻合,其中AG2-2ⅢB融合群首次从西南地区玉米上分离到。     

江苏大麦纹枯病菌的种类、分布及致病性的研究

 从江苏11个地区采集的大麦纹枯病病株上分离到92个丝核菌分离物,经菌丝融合测试,分别属于禾谷丝核菌的CAG1、CAG4、CAG5、AGC1、AGE,以及立枯丝核菌的AG1-IA,AG1-IC、AG2-1和AG5等9个不同的菌丝融合群,各群分离物数依次为76(82、6%)、1、2、4、2、1、1、2和3个。它们在感病大麦品种LEGIA和中抗品种CI3906。1上的致病性反应表明:不同丝核菌种间、不同丝核菌的融合群间、来自不同地区及来自同一品种上的菌株间,其致病性差异达到极显著水平;而同种丝核菌不同融合群间和不同品种间的菌株致病力虽有差异,但不明显;总的来讲,禾谷丝核菌的CAG1群菌株致病力最强,且分布广泛,其它各群致病力由强到弱的排列顺序为:AG5、AG1-1A、AGE、AGC1、CAG4、AG1-1C、CAG5和AG2-1。     

甘肃省安定区马铃薯黑痣病病菌菌丝融合群鉴定及其越冬能力初探

从甘肃省安定区采集了4个品种的马铃薯黑痣病薯块共18个样本,采用常规组织分离法分离纯化得到98株具立枯丝核菌典型特征的菌株,经DAPI染液观察其核相,结合载玻片配对法测定其菌丝融合群。结果表明,98株立枯丝核菌均为多核,介于3～25个之间。其中,AG3融合群20株(占总菌株数20.4%),AG5融合群60株(占总菌株数61.2%),AG9融合群8株(占总菌株数8.2%),10株与标准菌株均不融合(占总菌株数10.2%)。4个品种中不同菌丝融合群分离频率有差异。AG5融合群的分离频率均最高。其中,在庄薯3号的分离频率达65.5%,为甘肃省安定区马铃薯黑痣病优势菌丝融合群,且其越冬能力强于其他菌丝融合群。     

中国东北地区水稻纹枯病病原菌种类及融合群的分子鉴定

为明确中国东北地区水稻纹枯病病原菌种类及融合群的归属情况, 2015－2017年从黑龙江省、吉林省和辽宁省的17个水稻主产区采集水稻纹枯病标样, 分离获得水稻纹枯病菌214株, 运用水稻纹枯病菌的不同病原菌及融合群的特异性引物对214株水稻纹枯病菌进行病原菌种类和融合群鉴定, 并利用rDNA内转录间隔区(ITS)序列, 对供试水稻丝核菌的融合群归属进行了分析。结果表明:供试214株水稻纹枯病菌分属于茄丝核菌Rhizoctonia solani和水稻丝核菌Rhizoctonia oryzae-sativae, 菌株数分别为198株和16株, 占比分别为92.52%和7.48%。茄丝核菌菌株分属于2个融合群, 分别为AG1-IA和AG4, 菌株数分别为191株和7株, 占比分别为96.46%和3.54%。水稻丝核菌菌株均属于AG-Bb融合群, 菌株数为16株。不同年份水稻纹枯病的病原菌种类及融合群出现的频率和地域分布无明显变化, 而不同地域间水稻纹枯病病原菌的种类及融合群具有明显的分化特征, AG1-IA融合群在中国东北三省各个水稻产区均有分布且均为优势融合群, AG4融合群在辽宁省盘锦市出现频率最高, 水稻丝核菌AG-Bb融合群在吉林省吉林市、通化市和梅河口市出现频率最高。     

云南省马铃薯黑痣病病原菌融合群鉴定及8种药剂对其的毒力

由立枯丝核菌引起的马铃薯黑痣病是一种常见的土壤和种薯传播病害,在世界各地均有发生。本试验对分离纯化的67个丝核菌菌株进行融合群测定,结果表明:67个菌株都属于AG3融合群;对其中来自6个不同地域的11个菌株进行ITS测定,11个菌株的相似度为99%。8种药剂对马铃薯黑痣病菌的毒力测定结果表明,20%氟胺·嘧菌酯水分散粒剂50mg/L和25g/L咯菌腈悬浮种衣剂50mg/L的抑菌效果较好,室内抑菌效果可达100%。     

东北地区烟草靶斑病菌(Rhizoctonia solani)融合群、致病力分化及品种抗病性研究

2013-2014年吉林省、黑龙江省烟区首次大面积发生烟草靶斑病,损失严重。采集吉林省柳河县、黑龙江省林口县和宾县的烟草靶斑病病叶进行分离纯化,得到了12个菌株。将所获菌株分别与立枯丝核菌标准融合群菌株AG-2、AG-3、AG-4进行对峙培养,结果表明:此12个菌株均与立枯丝核菌AG-3标准菌株发生融合反应,不与其他融合群发生融合;随机选取3个县各1个代表性菌株,提取菌丝基因组DNA并对其ITS序列进行分析与比对,菌株HLJ-2、JL-1、HLJ-7的ITS序列与辽宁省烟草靶斑病菌菌株LF-2、LJT-8(AG-3融合群)的同源性达99%~100%,因此推断,吉林省、黑龙江省烟草靶斑病菌与辽宁省烟草靶斑病菌应属于同一个融合群,即立枯丝核菌AG-3融合群(Rhizoctonia solani AG-3)。根据各菌株在鉴别寄主上表现的抗性不同,可将吉林省、黑龙江省所有菌株分为3个致病类型,即致病类型Ⅰ、致病类型Ⅱ和致病类型Ⅲ。同一省份不同菌株间致病力有差异,黑龙江省菌株3种致病类型均有,以致病类型Ⅱ为主;吉林省菌株只有致病类型Ⅰ和致病类型Ⅱ。分别选取3个省的强致病力菌株,用离体叶片接种法鉴定了我国21个主栽烟草品种对靶斑病的室内抗病性,结果表明:没有免疫或抗病品种,‘龙江981’、‘NC297’对供试的3个强致病力菌株均表现中抗,‘中烟202’、‘云烟97’、‘NC55’、‘KRK26’和‘G28’分别对不同菌株表现中抗。     

中国中部5省(市)草坪禾草立枯丝核菌的菌丝融合群研究

 2003~2005年,从我国冷季型草坪与暖季型草坪过渡地区的上海市、浙江省、山东省、河南省和陕西省草坪褐斑病的病株样本中,分离得到了43个立枯丝核菌分离物,其寄主包括多年生黑麦草(Lolium perenne)、高羊茅(Festuca arundina-cea)、草地早熟禾(Poa pratensis)、匍匐翦股颍(Agrostis palustris)、结缕草(Zoysia japonica)和狗牙根(Cynodon dactylon)。按照Parmeter等的方法对该过渡带的草坪禾草立枯丝核菌分离物进行了菌丝融合群的测定,结果表明,上述5省(市)草坪禾草立枯丝核菌的菌丝融合群包括AG1-1A、AG1-1B、AG2-1、AG2-2ⅢB、AG2-2Ⅳ、AG-4和AG-5。不同省份、不同寄主草坪禾草的菌丝融合群类型略有不同,主要融合群类型为AG-1和AG-2。AG1-1B和AG2-1是草坪上首次报道的立枯丝核菌融合(亚)群。     

华北区玉米、高粱、谷子纹枯病病原学的初步研究

 玉米,高粱和谷子纹枯病在华北地区发生极为普遍,并日趋严重。作者从该区采集作物病组织,进行丝核菌分离、鉴定和致病性测定,从玉米上得到77个丝核菌分离物,分属立枯丝核菌(Rhizoctonia solani)中的AG-1-IA (68.8%) AG-1-IB,AG-3,AG-5等菌丝融合群(AGs)和禾谷丝核菌(R.cerealis)中的CAG-3,CAG-6,CAG-8,CAG-9,CAG-10等菌丝融合群,(CAGs).从高粱上得到26个分离物,分属AG-1-IA(77%),AG-4和AG5.谷子上得到30个分离物,分属AG-1-IA (80%)。和AG-4。另外从莠子上得到3个分离物,分离AG-1-IA和AG-4。主要融合群在不同作物和地理上有一定的一致性.致病性测定表明,AG-1-IA的分离物对寄主作物有极强的致病性,但分离物间的差异明显,AG-5的分离物对高粱致病力较强,CAG-10的分离物对玉米有较强的致病力,其余各融合群的分离物致病力均较弱。     

新疆北疆棉田立枯丝核菌不同菌丝融合群致病力的研究

从新疆北疆棉区采集了典型的棉花立枯病病苗及棉田土标样686份,按常规分离方法分离得到399个分离物,从中鉴定出272个纯化的立枯丝核菌(Rhizoctonia solani Kühn)菌株。用标准菌株,通过载玻片菌丝融合试验测定,将纯化的272个菌株划归为3个菌丝融合群:即AG-2、AG-4和AG-5,分别占总菌株的6.24%、84.2%和1.1%。另有23个菌株不与任何标准菌株融合,占8.46%,说明新疆北疆棉田立枯丝核菌的优势菌系是多核丝核菌的AG-4融合群。通过从10种不同配方培养基中筛选效果好的麦芽蛋白胨(MPDA)配方培养基(Ⅱ)进行对峙培养,将纯化获得的272个丝核菌菌株,划分为6个不同的营养亲和群。将多核的不同菌丝融合群及其各营养亲和群代表菌株在3种不同主栽棉花品种上(每品种都加不接菌的对照)进行温室盆栽致病力测定,结果以AG-4对棉花的致病力最强,其次是非融合类,AG-2和AG-5虽致病,但并不致死苗,其平均病指数分别为94.9、81.4、53.1、43.5。     

津黑两地大白菜褐腐病病原菌鉴定及生物学特性的比较

采用形态特征观察、致病性测定及rDNA-ITS序列分析等方法对天津、黑龙江两地大白菜褐腐病的病原菌进行鉴定。结果表明,天津、黑龙江两地大白菜褐腐病的病原菌为立枯丝核菌(Rhizoctonia solani Kühn),分离鉴定出TJ和DB两个菌株,分属立枯丝核菌AG-2融合群和AG-1融合群;DB菌株为一新菌株。两菌株菌丝生长最适温度均为25℃,最适pH为7,最适光照为12h。DB菌株菌丝生长速率快于TJ菌株;但TJ菌株先于DB菌株形成菌核,且形成量多。两菌株在碳源、氮源利用和菌核致死温度上也存在差异。     

绿豆立枯丝核菌研究初报

本研究通过形态学、菌丝融合群和致病力测定研究,对从河北省石家庄地区绿豆种植区分离的90个立枯丝核菌进行鉴定。在90个分离物中有71个属于AG4,占供试分离物的78.89%,2个属于AG2-2,占供试分离物的2.22%,另外17个分离物与标准菌株不融合,占供试分离物的18.89%;属于AG4的71个分离物中,55个与AG4完全融合（占77.46%）,16个与AG4不完全融合（占22.54%）。在温室条件下采用人工接菌法对40个代表性分离物的致病力进行测定,发现不同分离物对同一品种的致病力存在差异,其中分离物R3、R6、R9、R35致病力最强,分离物R23、R31-1致病力最弱。属于AG 4的分离物R3、R6、R9、R35与其他供试分离物致病力差异极显著;属于未知群体的分离物R20、R29和R24之间致病力差异极显著;属于AG2-2的分离物R21、R31-1致病力较弱,且差异不显著。     

Identification and pathogenicity of<Emphasis Type="Italic">Rhizoctonia solani</Emphasis> and binucleate<Emphasis Type="Italic">Rhizoctonia</Emphasis> anastomosis groups isolated from forage legumes in Erzurum,Turkey

Abstrast  Three-hundred-twenty-five isolates ofRhizoctonia (215R. solani and 110 binucleateRhizoctonia) were obtained from roots and crowns of alfalfa, sainfoin and common vetch grown in Erzurum, Turkey. The isolates were assigned to five anastomosis groups (AG) ofR. solani (AG-2-1, AG-3, AG-4, AG-5, and AG-10) and two anastomosis groups of binucleateRhizoctonia (AG-I and AG-K). In pathogenicity tests on alfalfa, sainfoin and common vetch, the highest disease severities were caused by isolates of AG-4 and AG-5. Isolates of AG-10 and AG-I were not pathogenic on the three tested forage legumes, whereas isolates of AG-K on alfalfa and sainfoin, and of AG-2-1 on sainfoin, were moderately virulent. Alfalfa isolate AG-3 was moderately virulent on sainfoin. This is the first report ofR. solani AG-3, AG-5, AG-10 and binucleateRhizoctonia AG-I on alfalfa. In addition, all theR. solani and binucleateRhizoctonia groups isolated from sainfoin and common vetch were recovered from these crops for the first time in Turkey. http://www.phytoparasitica.org posting Dec. 16, 2002.     

Anastomosis group and pathogenicity of isolates of Rhizoctonia solani from potato crops in South Australia

Isolates of Rhizoctonia collected from the stems, roots, tuber sclerotia and soil of potato crops in Virginia and Lenswood, South Australia, were identified to anastomosis groups (AG). Of the 301 multinucleate isolates of Rhizoctonia solani tested, 90% were AG-3, 7% were AG-4 and 2% were AG-5; 12 isolates were binucleate Rhizoctonia spp. This is the first report of isolates of AG-4 and AG-5 causing disease in potato crops in South Australia. All AG-3, AG-4 and AG-5 isolates tested caused rhizoctonia disease symptoms on the potato cultivar Coliban in pathogenicity trials conducted under glasshotise conditions. Both AG-3 and AG-5 isolates caused black scurf and stem cankers, although symptoms of black scurf were less severe with AG-5. AG-4 isolates produced the most severe stem and stolon cankers of all isolates tested. The pathogenicity of tuber-borne inoculum was confirmed by growing plants from sclerotia-infested tubers. AG-8 isolates from diseased barley and wheat produced severe root cankers and caused loss of feeder roots on inoculated potato plants. Results suggest that rhizoctonia disease in potato fields in South Australia is caused by a combination of different anastomosis groups and this has important implications for crop rotations.     

Aetiology of Rhizoctonia in sheath blight of maize in Sichuan

Rhizoctonia isolates obtained from maize grown in commercial fields in 33 representative counties (or cities) in Sichuan province in China were characterized according to colony morphology, hyphal anastomosis and pathogenicity. Of 141 isolates, 116 were identified as R. solani , 23 as R. zeae and two as binucleate Rhizoctonia . The isolates of R. solani were assigned to four anastomosis groups (AG): AG-1-IA (101 isolates, accounting for 71.6% of the total), AG-1-IB (2, 1.4%), AG-4 (9, 6.4%) and AG-5 (4, 2.8%). The two isolates of binucleate Rhizoctonia belonged to AG-K. On maize, isolates of AG-1-IA caused typical sheath blight symptoms. Lesions produced by isolates of AG-4, AG-5, AG-1-IB and AG-K were darker than those of AG-1-IA. Rhizoctonia zeae usually caused discontinuous lesions with a dark brown margin and a brown centre on the leaf sheaths, as well as ear rot. Isolates of AG-1-IA were the most virulent to maize, with an average lesion length of approximately 15 cm. Isolates of R. zeae produced lesions approximately 12 cm long, while those of AG-4, AG-5, AG-1-IB and AG-K were progressively shorter. On potato dextrose agar (PDA; pH 6.4), the minimum temperature for mycelial growth of R. zeae isolates was 14–18°C, the maximum 38–40°C and optimum 30°C. Isolates of R. zeae did not grow on PDA (28°C) at pH 2.0, the optimum for growth being pH 6.4.     

Characteristics and pathogenicity of isolates of Rhizoctonia spp. associated with damping-off of sugar beet

Rhizoctonia solani and R. cerealis were isolated from diseased sugar-beet seedlings in Ireland. Isolates of R. solani were assigned to anastomosis groups AG-2, AG-4, AG-5 and an unidentified group that did not anastomose with recognized tester isolates. Cultures of AG-2 were similar to those of AG-5 on oatmeal agar (OA) and potato-dextrose-marmite agar (PDMA). Cultures of AG-4, the unidentified group and R. cerealis were morphologically distinct from one another, AG-2 and AG-5. The optimum temperature for growth of AG-2 was 225 C, with optimum growth of AG-4, AG-5 and the unidentified group at 275-C. R. cerealis grew slower than all groups of R. solani, with optimum growth at 225°C. Hyphae of R. cerealis were significantly narrower than those of the groups of R. solani studied. In glasshouse pathogenicity tests, some AG-2 and all AG-4, AG-5 and isolates from the unidentified group caused damping-off of beet seedlings. In controlled environments of 10-25°C, an AG-2 isolate was the most aggressive at 10 C whilst AG-4, AG-5 and the unidentified group caused most disease at or above 15°C. R. cerealis was also pathogenic to beet seedlings, causing damping-off at 10 and 15 C.     

烟草靶斑病菌菌丝融合群及ITS序列分析

 烟草靶斑病是2006年我国新报道发生的一种叶部病害^［1］,其病原的无性世代为立枯丝核菌(Rhizoctonia solani Kühn),有性世代为瓜亡革菌(Thanatephorus cucumeris (Frank)Donk)。该病菌主要危害叶部形成病斑,对烟草的产量和品质影响显著,目前该病害主要分布在辽宁省丹东和铁岭地区,并呈现出迅速蔓延趋势。烟草靶斑病最早由巴西报道,此后,哥斯达黎加、美国、南非和津巴布韦也相继发生^［2,3］。     

Differentiation of Three Homogeneous Groups of Rhizoctonia solani Anastomosis Group 4 by Analysis of Fatty Acids

ABSTRACT Profiles of fatty acids from 70 isolates of Rhizoctonia solani anastomosis group (AG)-4 clustered into three groups, corresponding to homogeneous group (HG)-I, HG-II, and a newly described HG-III. Isolates from Georgia peanuts exhibiting limb rot were characterized as gas chromatography (GC) subgroup 1 (GC-1) and contained HG-I isolates. Isolates from diseased soybean hypocotyls grown in North Dakota and sugar beet seedlings, taproots, and tare soil in Minnesota and North Dakota were characterized as GC subgroup 2 (GC-2) and contained predominantly HG-II isolates but also included three distinct isolates based on fatty acid methyl ester (FAME) analysis and morphological features. Selected isolates from North Carolina cucumbers clustered into three distinct groups that corresponded to HG-I, HG-II, and the newly described HG-III. Distinct isolates from the soybean and sugar beet populations clustered with HG-III. Fatty acid profiles of AG-4 were compared with FAME library profiles of AG-1, AG-2 type 2, and AG-3, which were developed in previous studies and were sufficiently different that they could be used to support speciation of this group from R. solani. It is suggested that binomial R. practicola may be appropriate for the portion of AG-4 identified as HG-II.