亚麻品系9801-1对白粉病的抗性遗传分析

 The genetics of resistance against powdery mildew in flax was analyzed. The F₁ plants from reciprocal cross of resistant materials 9801-1 and three susceptible cultivars ILONA, VENUS and DIANE were resistant to powdery mildew. The ratio of resistant and susceptible plants in F₂ generation fitted the excepted 3 to 1. It was postulated that 9801-1 carded a single dominant and resistant gene.     

黄瓜-酸黄瓜渐渗系霜霉病抗性及感病前后几种酶活性的变化

 Using resistant and susceptible cultivars as controls, the resistant evaluation to Pseudoperonospora cubensis was carried out in 12 introgression lines from wide cross between cucumber(Cucumis sativus L.) and sour cucumber(Cucumis hystrix Chakr.). Three enzyme activities including POD, SOD and PAL were analyzed before and 7 d after inoculation, and the POD isozyme was detected by polyacrylamide electrophoresis. The inoculation results showed that, of the 12 accessions, 3 were identified as high resistant, 5 were moderately resistant and 4 were moderately susceptible to downy mildew. The enzyme activities of POD, SOD and PAL were greatly increased in resistant accessions after inoculation. PAL enzyme activities showed close correlation with disease rating before or after inoculation, which implicated that PAL enzyme activity might be used to estimate the resistance to downy mildew. POD isozyme electrophoresis showed that the number and intensity for the bands of resistant lines were significantly increased more than those of susceptible lines after inoculation.     

大麦条纹花叶病毒中国株三基因盒(TGB)序列对比分析

 The tripe gene block (TGB)genes of Barley stripe mosaic virus China strain (BSMV-CH)were amplified from cDNA of BSMV-CH RNAβ (GenBank accession No:AY789694)by PCR with special primer pairs, and cloned into pMD18-T vector for sequencing. Analysis of the sequences showed that the full length of BSMV-CH TGB1, TGB2 and TGB3 were 1 539, 396 and 468 bp, with deduced 512, 131 and 155 amino acids, respectively. BSMV-CH TGB1 shared 94.1%-95.4% nucleotide identities and 91.0%-94.5% amino acid identities with that of other BSMV strains, BSMV-CH TGB2 shared 96.5%-97.2% nucleotide identities and 98.5%-99.2% amino acid identities with that of other BSMV strains, and BSMV-CH TGB3 shared 95.7%-96.6% nucleotide identities and 94.2%-96.8% amino acid identities with that of other BSMV strains. Phylogenetic tree based on the amino acid of Hordeiviruses TGB genes showed that BSMV-CH was relatively closed to CV17 in genetic relationship. Therefore, BSMV-CH was deduced to be a recombined strain of CV17 and CV42.     

小麦-滨麦易位系M8657-1抗条锈病基因遗传分析和分子标记

 M8657-1, one of the wheat translocation lines derived from Leymus mollis Trin. Hara, is possessed of effective resistance at all stages to Su-ll and other dominant races of Puccinia striiformis f. sp. tritici in China. Seedlings of the parents, F₁, and F₂ progeny derived from the cross of M8657-1 (resistant) Mingxian169 (susceptible) were inoculated with Su-ll in greenhouse to identify and map the probable new stripe rust resistance gene. The results suggested that the stripe rust resistance in M8657-1 was conferred by a pair of recessive genes. Simple sequence repeat (SSR) technique was used to detect molecular marker associated with the resistance gene:208 pairs of wheat SSR primers were used to screen the two parents, as well as resistant and susceptible bulks and then three SSR markers were selected for genotyping the F₂ population. The geue, temporarily designated as YrLml, was found to be located on the chromosome 7DL and flanked by three SSR markers GDM67, WMC150 and WMC671, with the genetic distance of 5.0, 9.7 and 11.8cM, respectively.     

亚麻品系9801-1抗白粉病基因的RAPD标记

 F2 populations were obtained from the cross between 9801-1 and DIANE.Bulked segregate and RAPD analyses were employed to identify molecules linked to the resistance to powdery mildew.OPP02 amplified about 792 bp polymorphic band in all individuals from 9801-1 and resistant bulk,but absent in all individuals from DIANE and susceptible bulk.By further analysis in F2 segregating population,the polymorphic band was found to be cosegregated with the resistant gene possibly.The fragment was sequenced,     

草莓轻型黄边病毒3'末端序列多态性研究

 The 930 bp segment in 3' terminal region of Strawberry mild yellow edge virus(SMYEV) genome was amplified by 3' rapid amplification of cDNA ends(RACE).Ten Chinese isolates were sequenced,and 7 of them were the same.Nucleotide and amino acid identities and phylogenesis were analyzed between Chinese isolates and 24 isolates from other regions of the world.Sequence analysis of the 878 nt stretch within 3' terminal region of SMYEV genome showed that nucleotide acid identities ranged from 79.5% to 100%,deduced amino acid sequences of coat protein gene identity were 86.4% to 100%.Phylogenetic analysis showed that all isolates of SMYEV fell into four clades.To a certain extent,the clades were related with the geological distribution of SMYEV.Chinese isolates SY01 and SY04 lay in the same clade with European and American isolates,but formed a small separate branch.Isolates SY03 and SY02,derived from Fragaria×ananassa cv.Changhong-2 and F.pentaphylla respectively,had a far relationship with other isolates and fell into one clade.They were likely to be the special isolates that existed only in China.     

普通小麦-华山新麦草易位系H9020-1-6-8-3抗条锈病基因的遗传分析和SSR标记

 It have proved that wheat translocation line H9020-1-6-8-3 derived from Psathyrostachys huashanica Keng is an important resistant resource to stripe rust.To confirm the existence of resistant genes,it was crossed with susceptible cultivar MingXian 169 as male and female parent,respectively.Seedlings of parents and F₂ progeny were tested for resistance to selected CY29 of races of Puccinia striiformis f.sp.tritici from China.H9020-1-6-8-3 had one dominant resistant gene which temporarily named YrHs,whatever it was male or female parent.By using BSA method,two markers,Xgwm261 and Xgwm455 located on 2DL were found.The distance to YrHs were 4.3 and 5.8 cM respectively.The result could be used in molecular-assisted breeding.     

陕西省小麦赤霉病菌对多菌灵敏感性研究

 The mycelium growth rate method was used to test the sensitivity to carbendazim (MBC) at distinctive concentrations in 136 isolates of Fusarium graminearum from 19 counties of 6 districts in Shaanxi Province in 2008. The distinctive MBC concentration was 4 mg / L for testing of resistance and sensitivity. The results showed that average 50% effective concentration (EC50 ) of 136 tested sensitive isolates were (0. 908 6 ± 0. 062 3) mg / L. All the isolates were sensitive to MBC. The fungicide of MBC could be continually applied wheat production in Shaanxi.     

拮抗链霉菌B28 的分类鉴定及其生防作用研究

 An antagonistic Streptomyces strain B28, isolated from the soil collected in Tianmu mountain of Zhejiang Province, was identified as Streptomyces diastatochromogenes by morphological , physiological & biochemical characteristics and 16S rDNA sequence alignment. Antagonistic study indicated that its secondary metabolite toyocamycin had an antifungal activity on the mycelial growth of seven species of plant pathogenic fungi. The results showed that toyocamycin possessed marked inhibitory activity against Rhizoctonia solani and the EC50 value was 0. 58 μg / mL. The effective of toyocamycin against Botrytis cinerea and Fusarium oxysporum f. sp. cucumerinum was much higher than that against Colletotrichum gloeosporioides, the EC50 value of
toyocamycin in inhibiting B. cinerea, F. oxysporum and C. gloeosporioides were 13. 65 μg / mL, 12. 33 μg / mL, and 30. 15 μg / mL respectively.     

胶孢炭疽菌及两种疫霉菌对苯酰菌胺的敏感性与

选择对多菌灵、乙霉威和苯酰菌胺具有不同敏感性的胶孢炭疽菌Colletotrichum gloeosporioides、辣椒疫霉菌Phytophthora capsici及恶疫霉菌P. cactorum,分析其β-微管蛋白氨基酸突变与敏感性的关系。结果表明,胶孢炭疽菌对苯酰菌胺、多菌灵和乙霉威的敏感性与β-微管蛋白198位或200位氨基酸突变有关：对多菌灵敏感,对苯酰菌胺和乙霉威不敏感的胶孢炭疽菌β-微管蛋白氨基酸198位为谷氨酸（E）,200位为苯丙氨酸（F）;对多菌灵已产生抗性而对苯酰菌胺和乙霉威不敏感的菌株,其氨基酸200位由苯丙氨酸（F）突变为了酪氨酸（Y）;对多菌灵高抗,对苯酰菌胺和乙霉威敏感的菌株其氨基酸198位由谷氨酸（E）突变为了丙氨酸（A）。辣椒疫霉菌和恶疫霉菌对苯酰菌胺敏感,对多菌灵和乙霉威均不敏感。检测疫霉菌菌株β-微管蛋白未发现氨基酸突变,但发现其β-微管蛋白氨基酸在196~200位与胶孢炭疽菌差异较大,这可能是导致苯酰菌胺仅对疫霉菌有抑制效果的原因。     

胶孢炭疽菌及两种疫霉菌对苯酰菌胺的敏感性与β-微管蛋白氨基酸突变的相关性分析

选择对多菌灵、乙霉威和苯酰菌胺具有不同敏感性的胶孢炭疽菌 Colletotrichum gloeosporioides、辣椒疫霉菌 Phytophthora capsici 及恶疫霉菌 P.cactorum,采用菌丝生长速率抑制法及氨基酸序列比对法分析了其 β-微管蛋白氨基酸突变与敏感性的关系。结果表明,胶孢炭疽菌对苯酰菌胺、多菌灵和乙霉威的敏感性与 β-微管蛋白198位或200位氨基酸突变有关:对多菌灵敏感、对苯酰菌胺和乙霉威不敏感的胶孢炭疽菌 β-微管蛋白氨基酸198位为谷氨酸(E),200位为苯丙氨酸(F);对多菌灵已产生抗性而对苯酰菌胺和乙霉威不敏感的菌株,其 β-微管蛋白氨基酸200位由苯丙氨酸(F)突变为了酪氨酸(Y);对多菌灵高抗、对苯酰菌胺和乙霉威敏感的菌株其 β-微管蛋白氨基酸198位由谷氨酸(E)突变为了丙氨酸(A)。辣椒疫霉菌和恶疫霉菌对苯酰菌胺敏感,对多菌灵和乙霉威均不敏感。检测疫霉菌菌株 β-微管蛋白未发现氨基酸突变,但发现其 β-微管蛋白氨基酸在196~200位与胶孢炭疽菌差异较大,这可能是导致苯酰菌胺仅对疫霉菌有抑制效果的原因。     

辽宁省葡萄炭疽菌鉴定及对多菌灵敏感性研究

葡萄炭疽病已成为辽宁省葡萄生产上的重要病害。经对辽宁省主要葡萄产区24个葡萄炭疽菌株进行病原菌鉴定和采用生长速率法测定了葡萄炭疽菌对多菌灵的敏感性后,结果表明：引起辽宁省不同地区葡萄炭疽病的病原均为胶孢炭疽菌［Colletotrichum gloeosporioides (Penz.) Sacc.］。该病菌对多菌灵的敏感性测定值EC50的范围是0.267 8~2.731 2 μg/mL,平均值1.144 9 μg/mL。根据计算出的供试菌株的抗性系数和敏感性频率分布图所示,大部分菌株的抗药性表现为中抗水平,仅有1个菌株抗性较高,而不同敏感性频率分布呈不规则的正态分布,存在敏感性下降的风险。     

Identification of a novel point mutation in the <Emphasis Type="Italic">β</Emphasis>-tubulin gene of <Emphasis Type="Italic">Botrytis cinerea</Emphasis> and detection of benzimidazole resistance by a diagnostic PCR-RFLP assay

The molecular basis of resistance to benzimidazole fungicides with laboratory and field mutant isolates of Botrytis cinerea was investigated. After chemical mutagenesis with N-methyl-N-nitrosogouanidine (NMNG) two different benzimidazole-resistant phenotypes were isolated on media containing carbendazim or a mixture of carbendazim and diethofencarb. The mutant isolates from the fungicide-mixture-containing medium were moderately resistant to carbendazim with wild-type tolerance to diethofencarb while mutant isolates from carbendazim-containing medium were highly resistant to carbendazim but sensitive to diethofencarb. The studied field isolates were highly resistant to benzimidazoles and sensitive to diethofencarb. Study of fitness characteristics of benzimidazole highly-resistant isolates showed that the resistance mutation(s) had no apparent effect on fitness-determining parameters. Contrary to this, the moderately benzimidazole-resistant strains, with no increased diethofencarb sensitivity, had a significant reduction in certain ecological fitness-determining characteristics. Analysis of the sequence of the β-tubulin gene revealed two amino acid replacements in the highly benzimidazole-resistant mutants compared to that of the wild-type parent strain. One was the glutamic acid (GAG) to alanine (GCG) change at position 198 (E198A), identified in both laboratory and field highly benzimidazole-resistant isolates, a mutation previously implicated in benzimidazole resistance. The second was a novel benzimidazole resistance mutation of glutamic acid (GAG) to glycine (GGG) substitution at the same position 198 (E198G), identified in a highly benzimidazole-resistant laboratory mutant strain. Molecular analysis of the moderately benzimidazole-resistant strains revealed no mutations at the β-tubulin gene. A novel diagnostic PCR-RFLP assay utilising a BsaI restriction site present in the benzimidazole-sensitive (E198) but absent in both resistant genotypes (E198G and E198A) was developed for the detection of both amino acid replacements at the β-tubulin gene.     

Characterization and pathogenicity of Colletotrichum species associated with anthracnose on chilli (Capsicum spp.) in Thailand

Fungal isolates from chilli ( Capsicum spp.) fruits in Thailand that showed typical anthracnose symptoms were identified as Colletotrichum acutatum , C . capsici and C . gloeosporioides . Phylogenetic analyses from DNA sequence data of ITS rDNA and β-tubulin ( tub 2) gene regions revealed three major clusters representing these three species. Among the morphological characters examined, colony growth rate and conidium shape in culture were directly correlated with the phylogenetic groupings. Comparison with isolates of C . gloeosporioides from mango and C . acutatum from strawberry showed that host was not important for phylogenetic grouping. Pathogenicity tests validated that all three species isolated from chilli were causal agents for chilli anthracnose when inoculated onto fruits of the susceptible Thai elite cultivar Capsicum annuum cv. Bangchang. Cross-infection potential was shown by C . acutatum isolates originating from strawberry, which produced anthracnose on Bangchang. Interestingly, only C . acutatum isolates from chilli were able to infect and produce anthracnose on PBC 932, a resistant genotype of Capsicum chinense . This result has important implications for Thai chilli breeding programmes in which PBC 932 is being hybridized with Bangchang to incorporate anthracnose resistance into chilli cultivars.     

Characterisation of benzimidazole resistance of Cercospora beticola in Serbia using PCR-based detection of resistance-associated mutations of the β-tubulin gene

A survey to detect and characterise benzimidazole resistance within populations of Cercospora beticola in Serbia was performed. From 52 field isolates collected from sugar beet and beet root, only eight were found to be benzimidazole-sensitive based on the inhibition of mycelial growth by discriminatory concentrations of carbendazim and thiophanate-methyl. Sensitivity tests revealed the presence of three resistant phenotypes among the tested isolates: high-resistance (HR), low-resistance (LR) and moderate-resistance (MR). The benzimidazole resistant isolates were characterised based on the DNA sequence of the β-tubulin gene and temperature sensitivity. The HR isolates showed no temperature sensitivity regardless of carbendazim concentration, whereas the LR and MR isolates were sensitive at lower temperatures. Analysis of the β-tubulin gene sequence revealed two amino acid replacements in the benzimidazole-resistant isolates of C. beticola. One was a glutamic acid to alanine change at position 198 (codon GAG to GCG) that was identified in HR isolates; this mutation has previously been reported to be associated with the development of benzimidazole resistance in C. beticola. The second replacement was a novel point mutation of phenylalanine (TTC) to tyrosine (TAC) at position 167, identified in low and moderate benzimidazole-resistant isolates, sharing a single LR/MR β-tubulin genotype. A diagnostic PCR-RFLP assay utilising a BsaI restriction site present in the benzimidazole sensitive and LR/MR genotypes but absent in the HR genotype was developed for the routine detection of high resistance. A mutation-specific PCR assay was developed for the diagnosis of LR/MR genotype based on a mutation from T to A at codon 167, which is unique to this genotype.     

樱桃采后灰霉病菌对甲基硫菌灵、乙霉威和腐霉利的抗性

本文采用单孢分离法对四川汉源和山东烟台等地采集的樱桃果实进行了采后灰霉病的病原菌分离和鉴定;采用区分剂量法分别测定了菌株对苯并咪唑类杀菌剂甲基硫菌灵、乙霉威和二甲酰亚胺类杀菌剂腐霉利的敏感性,并进一步分析了抗药性菌株的分子机制。结果表明,分离得到的54株樱桃采后灰霉病菌均为灰葡萄孢Botrytis cinerea,对甲基硫菌灵的总抗性频率高达79.6%,其中甲基硫菌灵抗性-乙霉威敏感 (BEN R1) 菌株频率为 25.9%;甲基硫菌灵-乙霉威双重抗性菌株 (BEN R2) 频率为53.7%;检测到腐霉利抗性菌株 (DCF R) 9 株,频率为16.7%。甲基硫菌灵抗性菌株在β-tubulin基因上的突变共有2种类型: BEN R1抗性菌株中,第198位密码子发生点突变 (GAG→GCG),编码氨基酸由Glu (E)突变成缬氨酸Ala (A);在BEN R2抗性菌株中,第198位密码子发生点突变 (GAG→GTG),编码氨基酸由Glu (E)突变成缬氨酸Val (V)。DCF R菌株在BcOS1的第365位密码子由ATC突变成AAC或AGC,导致编码的氨基酸由异亮氨酸Ile (I)突变成天冬酰胺Asn (N)或丝氨酸Ser (S)。本研究表明樱桃采后灰霉病菌对甲基硫菌灵和腐霉利存在不同程度抗性,应在加强抗药性监测的同时与其他类型杀菌剂交替使用,延缓抗药性发展。     

海南省芒果可可球二孢对多菌灵的敏感性及菌株适合度研究

针对中国海南地区芒果蒂腐病致病菌可可球二孢对多菌灵的抗性水平及菌株的适合度进行了研究。采用区分剂量法,测定了2016年从海南省芒果园采集、分离的90株可可球二孢对多菌灵的敏感性,并对抗性及敏感菌株在菌丝生长、致病力、渗透压及相对渗率等方面进行了比较。结果表明:海南地区芒果可可球二孢对多菌灵的抗性频率为65.56%,且以高抗菌株为主（8个中抗菌株,51个高抗菌株）;该病菌对芒果危害甚大,其中具强致病力的菌株达65株,占72.22%。高抗菌株的菌丝生长优于敏感菌株,存在极显著差异（P0.01）;抗性菌株的致病力与敏感菌株无显著差异;敏感菌株的相对渗率高于抗性菌株,表明敏感菌株细胞膜的透性较高,胞内电解质渗出较多。研究表明,海南地区芒果可可球二孢对多菌灵的抗性水平较高,且抗性菌株适合度高于敏感菌株,易形成优势群体。     

Molecular characterization of benzimidazole-resistant B. cinerea field isolates with reduced or enhanced sensitivity to zoxamide and diethofencarb

Sensitivity profiles of Botrytis cinerea field isolates to zoxamide and the molecular basis of the resistance mechanism involved in cross-resistance relationships between benzamides, benzimidazoles and N-phenylcarbamates were investigated. B. cinerea isolates collected from southern, central and northern Greece were characterized based on their sensitivity to zoxamide, the benzimidazole carbendazim and the N-phenylcarbamate diethofencarb. Isolates exhibiting baseline sensitivity to carbendazim and zoxamide but no sensitivity to diethofencarb were considered wild type (S phenotype) and accounted for 44% of the total strains sampled. Thirty-three percent of the isolates had increased sensitivity (HS phenotype) to zoxamide and diethofencarb and were highly resistant to carbendazim compared to S isolates. Eight percent of the sample was highly resistant (HR phenotype) to all anti-tubulin agents studied. The rest of the isolates were moderately resistant to zoxamide (MR phenotype) and equally sensitive to benzimidazoles and N-phenylcarbamates compared to isolates of the S phenotype. Fungitoxicity tests with botrycides belonging to other chemical classes revealed no cross-resistance relationships between zoxamide and the phenylpyrrole fludioxonil, the dicarboximide iprodione, the hydroxyanilide fenhexamid, the anilinopyrimidine cyprodinil, the carboxamide boscalid and the strobilurin-type fungicide pyraclostrobin. Study of fitness characteristics did not show any significant difference between zoxamide resistant and sensitive isolates with respect to the parameters tested. PCR-RFLP analysis of a part of the β-tubulin gene sequence detected mutations in position 198 for both HS and HR zoxamide-sensitivity phenotypes. DNA sequence analysis of the B. cinerea β-tubulin gene revealed two previously described benzimidazole-resistance-conferring mutations. The first one was the glutamic acid (GAG) to alanine (GCG) change at position 198 (E198A), which was identified in all HS isolates. The second mutation (E198K) was a GAG-to-AAG substitution resulting in the replacement of glutamic acid with lysine present in all B. cinerea isolates highly resistant to all three anti-tubulin classes of fungicides. A number of mutations in other positions of the β-tubulin gene were detected in the moderately zoxamide-resistance phenotype.     

大麦云纹斑病菌中抗多菌灵乙霉威株系及其抗药性对致病性作用的分子分析

 田间抗性监测发现了大麦云纹斑病菌新型的抗性菌株,这类菌株对苯并咪唑类(多菌灵)、Phenylcarbamate(乙霉威)及三唑类(三唑醇)表现多重抗性,先前发现的多菌灵抗药性菌株均是在β-维管蛋白基因的198位点出现等位基因的突变,而新发现的菌株则仅在200位点(TTC)由苯并氨酸转变成赖氨酸(TAC)而导致对3种药剂的抗性。温室试验证明,这类菌株的致病性和野生敏感菌的致病性几乎一致,说明大麦云纹斑病菌对杀菌剂抗药性的发展与致病性之间没有相关性。