摘要:

AbstractLectins of cotton were isolated from either resistant or susceptible seed cultivars. In agar‐gel double diffusion tests, positive reactions took place between lectins of cotton cultivars and the antisera of their corresponding wilt Fusaria. The number of precipitin bands correlated with the degree of susceptibility of the tested cultivars. On the other hand, no visible reaction was detected when these antisera were subjected to react with either the resistant host or nonhost lectin

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00946.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractCowpea mosaic virus was one of the viruses isolated fromCrotalaria junceashowing mosaic, distortion and puckering symptoms. The virus induced local necrotic lesions inCanavalia ensiformis, Cassia occidentalis, Nicotiana debneyi, N. occidentalis, N. repandaandN. sylvestrisand some cultivars ofPhaseolus vulgaris4–6 days after inoculation. It induced local chlorotic spots, which later became necrotic, as well as systemic chlorotic spots, vein chlorosis, distortionand puckering inChenopodium amaranticolor.Sap from systemically infected cowpea cv. ‘C20‐55’was infective after dilution to 10−5but not 10−6, after 10 min at 65°C but not 70°C, or after 4 days, but not 5 days, at a room temperature of 15–25°C. Infectious virus was recovered from fresh reproductive tissues of infected cowpea cvs ‘C20‐55’and ‘Ife Brown’ plants

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00947.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA disease ofPandanus conoideuswhich causes leaf necrosis and fruit rot is reported from Morobe Province of Papua New Guinea. Biochemical, physiological and pathogenicity tests show the causal organism to be a strain ofErwinia carotovorasubsp.carotovora.The disease is common onP. conoideusand also affects leaves but not fruit ofP. julianettii, another pandanus widely grown in the area.

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00948.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractCherry blossoms inoculated with a rifampicin‐resistant strain ofPseudomonas syringaepv.morsprunorumdied or gave rise to fruits containing necrotic spots at or near the blossom ends. Scanning electron microscopy of developing fruits indicated that the pathogen had invaded the entire pericarp, including the endocarp. Bacteria also spread to the fruit stalk and, to a lesser extent, to the spurs. Mesocarp cells below the lesion collapsed. Infected fruit, stalks, and spurs contained, respectively,ca.109, 107, and 102colony forming units ofP. syringaepv.morsprunorumas determined by a dilution plate method on an agar medium supplemented with 50 μg/ml rifampicin. This is the first report of systemic spread ofP. syringaefrom blossoms to developing fruit of a deciduous cr

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00949.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIn the Heidelberg area of southwestern Germany declining trees ofAlnus glutinosa(L.) Gaertn. andPopulus tremulaL. as well as stunting shrubs ofCrataegus monogynaJacq. were observed. In all 3 species mycoplasmalike organisms, which appear to be the causal agents of the disorders, were detected by fluorescence and electron microscopy. The diseases of alder and aspen seem to be lethal while the hawthorn apparently is less affected.

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00950.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractSclerotinia sclerotiorumsurvived in infected seeds of white beans as dormant mycelium in testa and cotyledons. The rate of survival averaged 85 to 89% and did not change appreciably over a 3‐year period. When the infected bean seeds were sown in soil or sand, 88 to 100% failed to germinate. The seeds that failed to germinate, depending on the severity of seed infection, were rotted byS. sclerotiorum.In place of each seed, 3 to 6 sclerotia were formed. A low percentage of these sclerotia germinated carpogenically with or without preconditioning, (2.5 and 11.5% respectively). Myceliogenic germination of sclerotia with and without preconditioning was 35.5% and 70.5% on water agar and 81.0% and 93.0% on glucose agar, respectively. Both, preconditioning and nonpreconditioned sclerotia which were scattered on soil surface could germinate myceliogenically and infect bean leaves by contact. It is therefore, concluded that dormant mycelia in the infected seeds play an important role notonly in dissemination of the fungus but also in epidemiology of the diseas

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00951.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe severe strain of potato spindle tuber viroid (s‐PSTV) as well as chrysanthemum stunt (CSV) and cucumber pale fruit (CPFV) viroids were found to be transmitted through seed and pollen of the tomato cvs. Rutgers and Najwcześniejszy. Plants pollinated with a pollen infected with any of these three viroids became systematically infected. Plant, fruit and seed symptoms of viroid infection were noted on sap‐ and pollen‐inoculated plants and the yield of these plants was reduced.Tomato cv. Rutgers plants grown from infected seeds were symptomless although all three viroids were detected in these plants by bioassay and by electrophoresis on 5% polyacrylamide gel.When DNA complementary to s‐PSTV RNA was used for a direct viroid detection in seed samples by spot hybridization technique it hybridized not only with s‐PSTV RNA but also with CSV RNA as well as wit

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00952.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractPotato leaf roll virus (PLRV) was detected by enzyme‐linked immunosorbent assay (ELISA) when intact sprout, stem or leaf tissue disks were substituted for leaf or tuber extracts as test samples. Absorbance (A405) values increased with increasing number of disks per plate well. Readings with sprout disks were significantly higher than those with disks cut from other plant tissues or with tuber sap. A405values obtained by using 7 or 5 sprout disks per well were near the maximum oneobtained with leaf sap. PLRV was slightly more efficiently detected by ELISA in light sprout disks than in etiolated sprout ones. When ten out of 34 healthy tubers were replaced by PLRV‐infected ones in the tuber indexing test, the diseased samples werereliably detected with 5 etiolated sprout disks per well. The sprout disk sampling technique should be useful for qualitative evaluation of PLRV infection in sprouted potato tubers without necessity to wound them and using sprouts not long enough for macerat

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00953.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIntercellular fluid (IF) extracted from the apoplastic leaf spaces ofPetuniacontained up to 6 new soluble proteins, called d proteins (d0to d5). Characterisation of the d proteins has shown that they can be divided into groups and show a genetic variability similar to the PR(b) proteins fromNicotiana.d protein patterns fromPetuniainterspecific hybrids clearly show that the determinant for the d proteins in sexually transmitted as is the case for b proteins inNicotiana.d‐protein induction in TMV‐SM1infectedPetunialeaves is discussed in relation to the resistance to infection shown by cultivars and hybrids ofPetu

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00954.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractSix different inoculation methods have been tested to determinePseudocercosporella herpo‐trichoidesresistance of wheat using small seed‐samples. The observed differentiation among hosts corresponds to that known from the literature:‘Diplomat’ and ‘Caribo’ are susceptible whereas ‘VPM1’, ‘Rendezvous’ and ‘Roazon’ carry resistance transferred fromAegilops ventricosa.The modified method of Frauensteinand Roskothen(1979) seems to be most efficient: it is timesaving, easy to use and only small seed‐samples are necessary. Such resistance testing can be used in early generatio

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1988.tb00955.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY