摘要:

AbstractThe effect of different concentrations ofAzotobacter chroococcumexudates on microfungi isolated from Soybean phylloplane was studiedin vitroandin vivo. It has been found that the growth of some fungi was stimulated or suppressed whereas others showed fluctuations or remained unaffected depending upon the age of the plant, growth stage of the leaf, concentration of the exudates, method used to harvest fungi, and environmental conditions. Nutrient competition or production of biologically active substances like GA may be responsible for retarding the growth of fungi.

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00696.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractAn attenuated strain (L11A) of tobacco mosaic virus (TMV) induces no remarkable symptoms on tomato plants (Gotoand Nemoto1971) and has been used to protect tomato against virulent strains of TMV (Oshima1981), A temperature sensitive strain (Ls1) of TMV was isolated and found to have a malfunction of virus movement from cell to cell (NISHI‐GUCHIet al.1978, 1980). Those two strains are derived from a wild virulent strain (L). Coat proteins of them were compared with one another and with that of Dahlemense (D) strain of TMV, in order to see whether coat protein was associated with their respective characters.The coat proteins of the four strains behaved similar in both SDS‐polyacrylamide gel and 8 M urea polyacrylamide gel electrophoresis, suggesting that they are similar in molecular weight and charging effect in the gels. There was no significant difference in chromatographic pattern of tryptic peptides among the four strains. Amino acid compositions of tryptic peptides revealed that three strains, L11A, Ls1 and L, were identical to one another and that they differed from D slightly. These results suggest that coat protein is related neither to virus attenuation of L11A nor to the malfunction of

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00697.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractOut of 53 isolates Of Fusaria wheat, maize and barley 6 belonging o F. avena‐ceum produced citrin‐like compo

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00698.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe young multinucleate oogonium inAlbugois double‐walled with an outer layer exhibiting a negative staining reaction for insoluble polysaccharides and an inner layer which is strongly PAS‐positive. The oogonial nuclei exhibit an unusual staining behaviour with aniline blue showing an outer dark blue sheath of proteins surrounding a central hyaline nuclear core.Various histochemical localizations were performed for tracing the chronological sequence of development of the wall layers of the oospore. The first wall of the fertilized oospore was laid at the interphase of the periplasm and the ooplasm. Subsequent wall layers were formed both on the inner and outer side of the first oosporic wall. The second oosporic wall was formed just internal to the first one and exhibited faint PAS positivity. The third wall of the oospore was formed external to the first one and the PAS‐negative material for this was apparently contributed by the periplasm. This wall layer at later stages acquired a ridged appearance and these ridges in a mature oospore appear as distinct “pegs”. The last wall to be formed is the innermost one and it completely surrounds the central ooplasm. This wall layer is callosic

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00699.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe microinoculation procedure (inoculated are 0.02—0.05 mm2was carried out using the very thin tip of a stretched Pasteur pipette. It was dipped in a 500 μg/ml suspension of purified TMV, brought into contact with the upper epidermis of the leaf which had been dusted With an abrasive and rotated twice without actually pricking the leaf tissue. Five minutes later, the excess abrasive and virus were removed by rinsing the leaves under water. The procedure was applied to several tobacco‐TMV combinations. It induced the formation of single local lesions with over 90% efficiency on hypersensitively reacting hosts. Comparable efficiencies were obtained with systemically reacting hosts, as evidenced by a radiochemical procedure coupled with indirect ELISA (KONATE and FRITIG 1983). It was found that residual virus originating from the inoculum was negligible and could casily be distinguished form newly synthesized virus, even shortly after the microinoculation. This makes it possible to measure the rates of virus cell‐to‐cell spread and of virus multiplication at various times after inoculation and at various distances form the points of virus entry. These approadies can be extended to the comparison between differently reacting hosts and to the study of interference between different viruses or different virus

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00700.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractMycelia ofHyphochytrium catenoidesapplied to soil artifically or naturally infested withPhytophthora megaspermavar. sojae was effective in affording a high degree of protection of soybean plants against root rot in greenhouse tests. Seedling emergence, plant height and root diseases were restored to values near those of plants grown in soil without the pathogen, and root disease severity was greatly reduced, though never eliminated. Control was similar whether soil was treated withH. catenoides, then folded for 7 days before seeding, or if the flooding and prior incubation periods were eliminated. Abundant inoculum ofH. catenoideswas produced in a semi‐solid medium containing tryptone, glucose and yeast extract in which the colonies remained suspended. The inoculum, applied to vermiculite and stored in the laboratory, survived well: colony counts after 25 weeks were 63% of those present initiall

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00701.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractCallose formation in barley mutants, lines and varieties with different genes for resistance to powdery mildew in seven different loci was compared. Only barley with resistance genes in theml‐olocus showed so carly a callose formation passing off at such a high rate that it prevented fungal penetration.Ml‐(La)resistant varieties and near‐isogenic lines in‘Manchuria’with resistance genes in five other loci showed only a tendency to a larger callose formation than their susceptible counterparts after inoculation with avirulent as well as virulent powdery mildew.The callose formation inml‐oresistant barley was independent of the powdery mildew culture applied. This supports the hypothesis set forth as to why theml‐omutants are resistant against all known cultures or races of barley powdery mildew, and why this resistance may be more durable than other powdery mildew resistances. Further, this is the first case where the effect of callose refers to the action of a specific gene.Six susceptible Japanese varieties formed very large appositions but they were initiated as late as in other susceptible varieties, and their colour was plaer than in other barleys.NineHordeumspecies fell in one group with small appositions and another with appositions of the most common size in barley. Wheat reacts strongly with deep coloured appositions, rye with haloes with a somewhat diffuse margin, and oats large, central spots (papillae) nearly wit

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00702.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractBacterial antagonist B8 produced an inhibition zone with each of fourPhytophthora cactorumisolates on corn meal agar (CMA) plates. Infections with threeP. cactorumisolates were significantly reduced when the soil was simultaneously inoculated with B8. Growth ofP. cactorumwas completely inhibited on CMA amended with 40–100 per cent 10 fold concentrated B8 extract. Percent oospore germination ofP. cactorumwas significantly reduced when B8 was present in suspension for 9, 12 and 15 days from inoculation. Survival of oospores was significantly reduced at 60 and 90 mm depths in soil. Bacterial antagonist B8 significantly reduced the population of viableP. cactorumoospores in the top 30 mm of soil where oospores generally surviv

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00703.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe content of phenolic compounds as well as the activity of polyphenoloxidase and peroxidase in the red raspberry callus tissue afterD. applanatainfection were investigated. Two red raspberry cultivars: Latham — relatively resistant and M. Promise — susceptible were used.In the M. Promise cultivar the amount of phenols, especially o‐diphenols, decreased after infection and stayed more or less on the same level in Latham cultivar. The activity of polyphenoloxidase increased in both of the investigated cultivars, however in the tissue of Latham cultivar this rise was more pronounced than in the M. Promise one. The changes in peroxidase activity after infection were inconsiderable.The relation between the changes observed after infection in the phenolic metabolism and the differentiated susceptibility of callus tissue toD. applanataof the investigated cultivars was discussed.The obtained results explain partially the browning of infected callus tissue of one of the investigated cultivar i.e. M. Promise which had already been observed in the earlier investiga

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00704.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe presence of rod‐shaped viruses in German hops has been known for a long time and Hop Mosaic Virus (HMV) and Hop Latent Virus (HLV) were proved to be present by serological techniques. When another CARLA‐Virus, the American Hop Latent Virus was detected in England an extensive survey was carried out in the German hop growing regions and among wild hops. No natural occurrence of the virus could be detected. Only recently introduced plants of the American clone USDA 21055 in an isolated breeding garden were infected. Spread of the virus to German seedlings could not be detec

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00705.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY