ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05081.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYExpanding lesions resulted when conidia ofPhoma betaeFrank, mixed with rye pollen, were inoculated on to sugarbeet leaves by a standard technique. Conidia without pollen generally caused non‐expanding necrotic spots; these could be made to spread later by covering them with pollen or orange juice, but not with water.Germ‐tube growth was quicker on water agar than on sugarbeet leaves. Pollen extract stimulated germ‐tube growth on leaves 10 h after inoculation and resulted in the production of knots of hyphae overlying areas where intercellular hyphae could be discerned and where expanding lesions developed.Some inorganic salts mimicked the stimulatory effect of pollen on germtube growth on agar slides, but only a mixture of hexose sugars with boric acid reproduced the effect of pollen on both numbers and size of expanding lesions caused byP. betaeon sugarbeet leaves, and numbers of expanding lesions caused byBotrytis cinereaPers. ex Fr. on bean l

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05082.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYChlamydospores in tissue near the bases of plants and in attached soil particles were the main form of inoculum ofCentrospora acerina(Hartig) Newhall found on celery plants prepared for storage. Most of these spores remained ungerminated for several weeks but subsequently formed germtubes, terminal appressoria and infection‐pegs, which usually penetrated the plant surface through either the intact cuticle or damaged areas. For several weeks after the beginning of storage the plants were highly resistant to infection. During this time, appressoria failed to penetrate the intact cuticle and, if the fungus entered through damaged areas, hyphal growth in tissue was suppressed. Infection was often found to be associated with abrasion or splitting of the cuticle in commercially stored plants and, in experiments, deliberate damage enhanced the probability of infection. The development of the disease was much slower at 2 d̀C than at 15 d

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05083.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYBenomyl (methyl‐I‐(butyl carbamoyl)‐2‐benzimidazole carbamate) at 2.5 to 100 ppm completely inhibited the growth invitroofCephalosporium maydisSamra, Sabet&Hingorani, the causal fungus of late‐wilt of maize. In pot experiments, late‐wilt was controlled by applications equivalent to 10 ppm benomyl/unit wt dry soil at sowing but not by applications 30 days after sowing or by seed treatments (dusts and dips). A fungitoxic substance was detected in benomyl‐treated soil, planted with maize, 120–150 days after treatment and for 150–180 days in unplanted soil. Sap expressed from maize grown in benomyl‐treated soil was also fungitoxic, especially that from the roots and distal parts of the leaf blades.In the field, soil applications of benomyl to 10 kg/feddan (4200 m2) failed to control late‐wilt. Tests indicated little fungitoxicity in the sap of maize plants

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05084.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYThe symptoms and virus content of isogenic tomato genotypes differing by three tobacco mosaic virus (TMV) resistance factors,Tm‐I, Tm‐2andTm‐22, were studied in relation to various isolates of TMV and four strains were identified. The common strain induced no symptoms on plants with any of the factors for resistance, one strain caused symptoms onTm‐Iplants, one onTm‐2plants and one on bothTm‐IandTm‐2plants and also onTm‐I Tm‐2plants. No strain induced symptoms onTm‐22plants.The gene,Tm‐I, was found to be dominant or incompletely dominant for preventing symptom development but was recessive or intermediate for limiting virus multiplication of the common strain. BothTm‐2andTm‐22were dominant for a hypersensitive response to the common strain. Virus multiplication was temperature‐dependent. The background or varietal genotype did not affect virus multiplication.A systemic necrosis ofTm‐22plants occurred only when heterozygousTm‐22was not protected by other factors against specific strains of TMV.The complexity of the host genotype, pathogen genotype and environment interactions are outlined and the exploitation of the resistance facto

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05085.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYUsing a micro‐container inoculation technique, an English strain of raspberry ringspot virus (RRV) was transmitted byLongidorus caespiticolaHooper,L. leptocephalusHooper andXiphinema diversicaudatum(Micol.) to petunia test plants. RRV persisted in starvedX. diversicaudatumfor at least 10 days. From a mixed infection of RRV and a typical strain of arabis mosaic virus (AMV), batches of fiftyX. diversicaudatumtransmitted both viruses, but AMV the more readily, whereas batches of twenty‐fiveL. caespiticolatransmitted both viruses with equal facil

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05086.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYMicroprecipitin tests demonstrated a distant serological relationship between intact virus particles of BCMV and BYMV. Antiserum titres of 2048–4096 and 16–128 (reciprocals of dilution end‐points) were found for homologous and heterologous antigens, respectively. Cross‐reactivity, however, was not obtained in agar immunodiffusion tests when the antigens, in purified preparations or crude infective sap, were treated with pyrrolidine or when the reactants were placed in agar gels containing sodium dodecyl sulphate. Only homologous antigens produced a precipitin line; homologous antiserum titre was 16.In comparative immunodiffusion trials, single‐radial‐diffusion tests (antiserum incorporated in agar) were much more sensitive than double‐diffusion tests for detecting low virus concentrations.Analyses of virus proteins by polyacrylamide‐gel electrophoresis demonstrated that coat protein of each virus was composed of a single polypeptide chain with a molecular

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05087.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYBy delaying harvest of fruit bunches of the oil palmElaeis guineensisJacq., an increase in their oil content can be obtained, but this is accompanied by increased harvesting costs and lower oil quality, as the number of detached fruit increases. Treatment of ripening bunches with auxins, gibberellic acid, or ethephon retards fruit abscission, and harvest can be delayed by up to 5 days without increase in the number of detached fruit. Indications are that oil yield might increase by more than 5% during this period, without change in harvesting costs or oil quality.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05088.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

SUMMARYSelf‐rooted tomatoes ‘Ailsa Craig’ and ‘Kingley Cross’, and scions of ‘Ailsa Craig’ grafted on to different rootstocks, were grown in soil infested with different numbers ofHeterodera rostochiensis(Mainly pathotype A). Three rootstocks (RS4, RSKN, ISKVF) tolerated damage from nematode populations of up to 125 eggs/g soil, but nematodes increased up to x45 on them. Two nematode‐resistant F1hybrid rootstocks, B6633(exLycopersicon pimpinellifoliumB6173) and B6015(exL. hirsutumvar.glabratumB6013), tolerated up to 125 eggs/g soil; nematode populations declined as much as 80% under B6633, and increased little under B6015. On the self‐rooted ‘Ailsa Craig’ and ‘Kingley Cross' the numbers of nematodes increased markedly (maximum increase x40), and greatly affected growth and yield so that initial populations greater than 62 eggs/g s

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05089.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb05090.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY