枣缩果病病原子实体的诱导和鉴定

１９９２～１９９６年作者对枣缩果病病原研究认为该病由Ｃｏｎｉｏｔｈｙｒｉｕｍｓｐ．（Ｃ．ｓｐ）、Ａｌｔｅｒｎａｒｉａａｌｔｅｒ－ｎａｔａｆ．ｓｐ．ｔｅｎｕｉｓ和一种半知菌亚门有隔有色丝状菌等多病原引起。经室内外对上述病原菌的子实体诱导，以及越冬后自然病果上子实体的发现，病原菌Ｃ．ｓｐ．经再鉴定为Ｃ．ｏｌｉｖａｃｅｕｍＢｏｎ，另一病原菌半知菌亚门有隔有色丝状菌订名为群生小穴壳菌ＤｏｔｈｉｏｒｅｌａｇｒｅｇａｒｉａＳａｃｃ。至此明确引起枣缩果病的病原为Ｃ．ｏｌｉｖａｃｅｕｍ、Ａｌｔｅｒｎａｒｉａａｌｔｅｒｎａｔａｆ．ｓｐ．ｔｅｎｕｉｓ、Ｄｏｔｈｉｏｒｅｌａｇｒｅｇａｒｉａ和一种细菌（待鉴定）     

临夏地区春蚕豆根腐病发生与为害调查

对甘肃临夏地区的３４０块春蚕豆田根腐病的调查，明确了该区蚕豆根腐病死亡率为１％～９０％，平均为１５．３３％；死亡率小于１０％的地块占调查地块总数５９．７％，大于３０％地块占１７．３５％，随着海拔梯度的增高，蚕豆死亡率逐渐下降。病原真菌主要有腐皮镰刀菌（Ｆｕｓａｒｉｕｍｓｏｌａｎｉ）、燕麦镰刀菌（Ｆ．ａｖｅ－ｎａｃｅｕｍ）、粘帚霉（Ｇｌｉｏｃｌａｄｉｕｍｒｏｓｅｕｍ）和尖孢镰刀菌（Ｆ．ｏｘｙｓｐｏｒｕｍ）     

甘肃省临夏州小麦脚腐病病原鉴定

对甘肃省临夏州小麦脚腐病病原进行了分离鉴定,从3块病田的37株罹病小麦上分离得到56个真菌菌株,分别被鉴定为雪腐镰刀菌[Fusarium nivale(Fr.)Ces.]、燕麦镰刀菌[Fusarium avenaceum(Corda et Fr.)Sacc.]、麦斑点附球霉[Epicoccum triticiP.Henn.]、小壳色单隔孢菌[Diplodiellasp.]、交链孢菌[Alternariaspp.]、芽枝霉[Cladosporiumsp.]、黑孢霉[Nigrosporasp.]。其中,雪腐镰刀菌致病性最强,燕麦镰刀菌致病性中强,麦斑点附球霉致病性弱,其余菌不致病。     

枣铁皮病病原鉴定

 枣铁皮病主要为害大枣果实,可导致果实腐烂和提早落果,据症状特点可分为铁皮型和缩果型2种类型。1993~1995年对河北和河南2省6个不同枣区大枣铁皮病病果进行分离、接种和再分离,证实枣铁皮病病原为:链格孢Alternaria alternata(Fr.) Keissler;实腐茎点霉Phoma destructiva Plowr,壳梭孢属一种真菌Fusicoccum sp.3种病原真菌可以单独或混合侵染。     

小麦黑胚病及其对种子发芽出苗的影响

本试验表明链格孢菌（Ａｌｔｅｒｎａｒｉａｔｅｎｕｉｓ）是引致小麦黑胚病的主要病原菌，占病原分离物９１％。黑胚病虽然对种子的发芽没有明显影响，但显著影响出苗率和幼苗生长力。当前推广的品种中，黑胚率为１１．１％左右，严重的高达４２．８％。     

五味子茎基腐病发生初报

通过对辽宁省多个地区的调查,发现此病害发生普遍,尤其是二年生的五味子茎基腐病发生严重。五味子茎基腐病在5月上旬开始出现,6月初为发生盛期。本文对五味子茎基腐病进行了症状描述,并对不同地点采集的病样分别进行木质部和韧皮部病原物的分离、纯化。对分离得到的菌株按照柯赫氏法则进行致病性测定并对病原菌进行鉴定,结果表明,此病害可由木贼镰刀菌(Fusarium equiseti)、茄腐镰刀菌(F.solani)、尖孢镰刀菌(F.oxysporum)和半裸镰刀菌(F.semitectum)4种镰刀菌属真菌引起。针对此病害的发生特点,提出了相应的防治措施。     

山西壶瓶枣缩果病病原菌分离和鉴定

 2005~2008年山西壶瓶枣缩果病害发生严重,造成了巨大的经济损失。本文利用真菌ITSrDNA和细菌16S rDNA基因的通用引物,分别对分离自山西晋中的罹病壶瓶枣果实表面寄生真菌和细菌基因组DNA进行PCR扩增,将扩增产物进行核苷酸序列测定,在GenBank数据库进行Megablast同源性分析,确定壶瓶枣果实的主要寄生菌是细极链格孢菌(Alternaria alternata)、白囊耙齿菌(Irpex lacteus)、青霉菌(Penicillium expansum)、芽枝孢菌(Cladosporium tenuissimum)4种真菌和枯草芽孢杆菌(Bacillus subtilis)、巨大芽孢杆菌(B.megaterium)、短小芽孢杆菌(B.pumilus)、多粘类芽孢杆菌(Paenibacillus polymyxa)4种细菌。回接试验证明链格孢菌、青霉菌、芽枝孢菌是壶瓶枣果实主要的致病真菌,而所分离的细菌没有致病性。     

胡卢巴灰斑病及其种子带菌的初步检验

经鉴定胡卢巴灰斑病病原菌为尾孢属真菌ＣｅｒｃｏｓｐｏｒａｔｒａｖｅｒｓｉａｎａＳａｃｃ．，该病及病原真菌在国内尚未见报道。文中简要描述了病害症状及病原菌的形态特征。用吸水纸法对发病田播种用的种子及当年病田所产种子进行样品检验，带菌率分别为１５％和４８％。初步认为种子带菌是病害发生的重要初侵染源     

河南省玉米细交链孢菌叶枯病的初步研究

１９９４～１９９５年在河南省新乡、辉县等地玉米上分离到１株交链孢菌ＡｌｔｅｒｎａｒｉａｔｅｎｕｉｓＮｅｅｓ。新乡市郊区玉米生长后期普遍受此菌侵染，主要为害叶片及苞叶，叶鞘亦可发病，玉米发病率为１４％～５３％，严重影响玉米的产量     

枣干腰缩果病症状类型及侵染规律研究

试验明确枣干腰缩果病在田间呈现３种症状类型,即干腰型、干肩型和干蒂型。对上述３种症状的病果分离结果表明其病原种类没有明显差别,都以真菌为主,其中细交链孢菌比例最大。从开花期至采收前,每隔１０ｄ采样分离表明,病菌从花期至收果前均可造成侵染。     

野生酸枣内生细菌筛选、鉴定及其抑菌活性测定

为广泛开发植物内生菌资源,采用组织分离法从野生酸枣的根、茎、叶和果实中进行生防菌的分离和筛选,通过平板对峙法和发酵液法测定了所得菌株对8种植物病原菌的活性,并利用生物学和分子学方法对所得菌株进行了鉴定。结果显示,从野生酸枣的根、茎、叶和果实中共分离得到76株内生细菌;通过对所有菌株进行初筛和复筛,最终得到8株拮抗作用较强的菌株,菌株SZG-23、SZG-1、SZY-13和SZS-3对梨黑斑病菌Alternaria kikuchiana和黄瓜枯萎病菌Fusarium oxysporum f.sp.cucumerinum的抑制作用较强,抑制率均分别高于82.5%和71.1%,其中菌株SZG-23的抑制率最高,达90.3%和72.4%。菌株SZG-23发酵液对8种植物病原菌生长均有一定的抑制作用,其中对梨黑斑病菌和番茄灰霉病菌Bortytis cinerea的抑制作用最好,抑制率分别达92.2%和90.5%。菌株SZG-23的抗利福平突变菌株能在酸枣幼苗中定殖和移动。结合形态观察、生理生化特征及16S r DNA同源性分析将菌株SZG-23鉴定为解淀粉芽胞杆菌Bacillus amyloliquefaciens,16S r DNA序列在Gen Bank中登录号为KF483660。     

Investigation and rapid detection of fungal pathogens causing mulberry sclerotial disease in south-west China

Mulberry sclerotial disease is a destructive disease that afflicts mulberry fruits throughout the world. In recent years, the impact of mulberry sclerotial disease has increased with the development of the mulberry fruit industry. Ciboria carunculoides, C. shiraiana, and Scleromitrula shiraiana are all pathogens causing mulberry sclerotial disease, but the dominant pathogen may be different in different mulberry planting areas. In this study, we investigated the causal agents of mulberry sclerotial disease in Chongqing and Sichuan, the main mulberry planting areas in south-west China. The results showed that C. carunculoides was the dominant pathogen in the investigated areas, and the disease incidence rate on some widely cultivated mulberry varieties exceeded 90%. Based on the differences in internal transcriber spacer sequences of different pathogens, we developed a method using cleaved amplified polymorphic sequences (CAPS) from digestion with the three restriction enzymes HindIII, EcoRI, and MluI for rapid detection of pathogens on mulberry fruits. Use of this method confirmed that the diseased fruits of some mulberry varieties were infected by a mixture of C. carunculoides and S. shiraiana. Long-fruit mulberry, which was considered to be resistant to sclerotial disease in the past, was also infected by C. carunculoides. Diseased fruit infected by C. shiraiana or by S. shiraiana alone were not detected. Our results suggest that C. carunculoides is probably the dominant pathogen causing mulberry sclerotial disease in south-west China. The CAPS method for rapid detection of pathogens could assist diagnosis, epidemiology, and disease monitoring.     

引起乙烯褪绿蜜橘果实腐烂的主要致病真菌分离及鉴定

为明确贮藏过程中乙烯褪绿蜜橘果实腐烂的主要致病真菌,以重庆市北碚产区无核蜜橘为研究材料,利用乙烯利对其果实进行褪绿处理,观察贮藏期间褪绿蜜橘果实的发病症状,确定病害种类,统计发病率;并从发病果实中分离主要致病真菌,采用形态学特征观察和ITS序列分子生物学分析对其进行鉴定。结果表明,乙烯褪绿加剧贮藏蜜橘果实病害的发生。从发病果实中共分离出5株主要致病真菌菌株,分别编号为A、B、C、D、E;结合形态学特征和5株致病真菌的ITS序列分析结果,A、B菌株均被鉴定为胶孢炭疽菌Colletotrichum gloeosporioides,但这2株菌株具有不同的菌落形态及致病特性;C菌株被鉴定为焦腐病菌Lasiodiplodia theobromae;D菌株被鉴定为交链格孢菌Alternaria alternata;E菌株被鉴定为棘孢曲霉Aspergillus aculeatus。A、B菌株引起的果实腐烂占乙烯褪绿蜜橘总腐烂果实的81.96%,是引起贮藏过程中乙烯褪绿蜜橘果实腐烂的主要致病真菌,其次为C菌株,D、E菌株为次要致病真菌。     

Effect of infection by the shot-hole fungus,Wilsonomyces carpophilus,on drop and quality of almond fruit 1

Almond fruits were inoculated with suspensions containing 10³, 10⁴ or 10⁵ conidia per mL of Wilsonomyces carpophilus beginning when fruits emerged from the hypanthium and continuing at approximately weekly intervals until they reached full size and embryo development began. More small than mid-sized fruits fell and abscission ceased when fruits reached maximum size. Abscission of mid-sized fruits generally increased with increasing inoculum concentration, and lesions were most abundant on mid-sized fruits. The kernel quality of infected and healthy fruits were compared in 1994 and 1995. Mid- to full-sized fruits were inoculated one or three times with 10 conidia per mL of W. carpophilus. Kernels from inoculated and non-inoculated fruits did not differ in weight, length, or percentage of kernels covered with gum deposits or incompletely filled.     

Susceptibility of European pear cultivars to Pseudomonas syringae pv. syringae using immature fruit and detached leaf assays

The susceptibility of thirty-three pear cultivars and two pear rootstocks to four virulent strains of Pseudomonas syringae pv. syringae was evaluated by inoculating detached immature fruits and young leaves. The four strains were similarly virulent and did not show cultivar specificity although they were isolated from different pear cultivars and exhibited different biochemical profiles. The most frequently planted pear cultivars, Conference, Abate Fetel, General Leclerc, Williams, D. Comice, El Dorado, Alexandrine, B. Anjou, Passe Crassane and the rootstock OHxF 333 were susceptible to P. syringae pv. syringae. Maximal severity values were obtained on 'Preguystar' leaves (about 90%). The rootstock Winter Nelis was less susceptible. Results with immature fruit and detached leaf assays agreed with field observations on cultivar susceptibility to bacterial blast. However, the detached leaf test gave a more accurate prediction and has the advantages that symptoms develop quickly (48 h), and leaves are available for a longer period of time than fruits. This method is proposed as a rapid and reproducible screening system of cultivar susceptibility to bacterial blast of pear.     

桑椹瘿蚊生物学特性及其化学防控

为探索桑椹瘿蚊Cotarina sp.生物学特性,并进行有效地化学防控,通过调查桑椹瘿蚊的发生期,观察并记录其各部分形态特征,同时统计了乐果对桑椹瘿蚊的防治效果,并采用高效气相层析法测定了成熟桑椹中乐果的残留量。结果表明:桑椹瘿蚊为完全变态昆虫,经历卵、幼虫(休眠体)、蛹、成虫4个阶段,每年3月开始羽化为成虫,成虫不取食桑椹,可存活2~4 d,雌雄成虫傍晚交配,产卵于桑椹小果中,卵经6~7 d孵化为幼虫,幼虫从果柄中心取食桑椹,导致桑果局部畸形(干瘪)、早熟;幼虫经历3个龄期,老熟幼虫弹跳入土,形成休眠体进行越夏越冬,翌年2月化蛹。喷洒乐果乳剂1 000倍稀释液后,桑椹虫害率由83.3%降低到15.0%,被害桑椹虫口密度下降了89.3%;经高效气相色谱法分析,乐果残留量仅为0.75 mg/kg,低于国际标准,表明乐果对桑椹瘿蚊的防治效果较好。     

Dynamics of post‐harvest pathogens Neofabraea spp. and Cadophora spp. in plant residues in Dutch apple and pear orchards

Post‐harvest diseases of apple and pear cause significant losses. Neofabraea spp. and Cadophora spp. infect fruits during the growing season and remain quiescent until disease symptoms occur after several months in storage. Epidemiological knowledge of these diseases is limited. TaqMan PCR assays were developed for quantification of N. alba, N. perennans, C. malorum and C. luteo‐olivacea in environmental samples. Various host tissues, dead weeds and grasses, soil and applied composts were collected in 10 apple and 10 pear orchards in May 2012. Neofabraea alba was detected in 73% of samples from apple orchards and 48% from pear orchards. Neofabraea perennans was present in a few samples. Cadophora luteo‐olivacea was detected in 99% of samples from apple orchards and 93% from pear orchards, whilst C. malorum was not detected in any sample. In apple orchards, highest concentrations of N. alba were found in apple leaf litter, cankers and mummies, and of C. luteo‐olivacea in apple leaf litter, mummies and dead weeds. In pear orchards, N. alba and C. luteo‐olivacea were found in highest concentrations in pear leaf litter and in dead weeds. Substrate colonization varied considerably between orchards. The temporal dynamics of pathogens was followed in four apple orchards and four pear orchards. In apple orchards the colonization by pathogens decreased from April until August and increased from September until December. This pattern was less pronounced in pear. Knowledge on population dynamics is essential for the development of preventative measures to reduce risks of fruit infections during the growing season.     

Fruit rot of sweet pepper caused by <Emphasis Type="Italic">Stemphylium lycopersici</Emphasis> in Japan

A severe rot of postharvest fruits of sweet pepper, a variety of Capsicum annuum, was found in Kagawa Prefecture in southwestern Japan in August 1999. A fungus, isolated repeatedly from the diseased fruits and identified as Stemphylium lycopersici, was demonstrated to be pathogenic to fruits of sweet pepper. The disease was new to Japan, and the fungus was added to the pathogens causing fruit rot of C. annuum.     

Bacteria from four phylogroups of the Pseudomonas syringae complex can cause bacterial canker of apricot

Pseudomonas syringae is described as a species complex, containing P. syringae-related species classified into 13 phylogroups and 23 clades. Pseudomonas syringae is one of the main pathogens of fruit trees, affecting nut trees, hazelnut and kiwi, pome and stone fruits. Bacterial canker of apricots is an important disease in regions of production with cold winters and conducive soils. This work characterizes the bacteria able to induce canker in apricots isolated in different French orchards. Bacteria from four phylogroups were able to induce canker. The pathogenicity to apricot was not linked to the pathogenicity to the three herbaceous species and cherry fruits tested, and was not always related to hypersensitive reaction on tobacco and ice nucleation activity. Bacteria pathogenic to apricot belong to phylogroups 01, 02, 03 and 07. The bacteria of phylogroups 01a and 07a (Pseudomonas viridiflava) characterized in this work have not previously been described as pathogenic to apricot.