ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06425.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe amount of protein produced per m2by plants cultivated in soil in a greenhouse at three levels of fertilizer application, forc. 10 weeks, was estimated by Kjeldahl analysis of the TCA‐insoluble fraction of freeze‐dried material. The quantity of protein extractable for production of leaf protein concentrates was determined by Kjeldahl analysis of non‐dried but frozen material after disintegration with a meat mincer and an Ultra‐Turrax homogenizer, hydraulic pressing and filtration, and protein precipitation by heat (in two steps) or by TCA. The precipitability was also studied by Folin‐Ciocalteu determination of protein. The quality of each protein concentrate was studied by determining nitrogen content (Kjeldahl), digestibility by pepsin and by pepsin + pancreatin, nutritive value inTetrahymenatests, and lysine and methionine content (analysed microbiologically). Twenty‐nine species and varieties were investigated. Large differences between species were found in all the properties studied. Protein extractability varied between 5 and 80%, while the extractable protein produced per m2ranged between 1 and 140 g. The highest digestibility was two to three times greater than the lowest one. In the most digestible species (Amaranthus caudatus), 82% of the N of the chloroplastic protein concentrate was digested by pepsin + pancreatin. TheTetrahymenavalue generally ranged between 40 and 98, whereas casein gave values of about 75. The lysine content always exceeded the FAO minimum. The methionine content of most species varied between 2.0 and 2.2% of the hydrolyzed protein.Amaranthus caudatusand the Chenopodiaceae investigated were the most suitable species for large‐scale production of leaf protein concentrates for human consumption because they gave high yield of extractable protein and high‐quality prote

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06426.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe basis of differences in yield between six sugar‐beet varieties was studied by measuring the changes in their leaf areas and dry weights throughout the season. Initially, dry‐matter production was determined by the rate at which leaf area developed, but this effect did not persist to final harvest. Varieties that maintained the largest net‐assimilation rates in September produced largest sugar yields. Characteristically, these varieties showed the smallest losses in lamina dry weight through leaf senescence late in the season, and put the largest proportion of their photosynthate into root produ

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06427.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYPotato plants infected withVerticillium albo‐atrum, whether they showed disease symptoms or not, invariably had a lower leaf water content than healthy plants. This water content fell throughout the growing season as the disease progressed and showed greater diurnal fluctuations than in healthy plants. Wilting appeared in diseased plants when a water saturation deficit ofc. 20% was attained, but in healthy plants occurred at marginally lower deficits. The acropetal development of wilting symptoms was reflected in the gradient of water deficits along the main axis of the plant.Deficits of 10–28%, which commonly occurred in infected plants grown both in pots and in the field, would suggest that these plants are experiencing internal water stress throughout much of the season, and consequently may have reduced rates of photosynthe

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06428.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYTomato seedlings, grown in the glasshouse, were sprayed with solutions of 3,5‐dichlorophenoxyacetic acid as sodium salt at 2 times 10‐5, 4 times 10‐5and 10‐4M. The treated plants became dark‐green, dwarfed, and compact. After 6–7 weeks normal growth was resumed. Measurements and analytical data on treated and control plants ar

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06429.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYTreatments that produced different rates of growth in attached tobacco leaves and leaf discs, also affected the growth of powdery mildew on them.Topping (removal of flower head) increased the resistance of upper leaves, and attached leaves of topped and intact plants were more susceptible than leaf discs from them incubated on water.Hyphal growth increased on leaf discs incubated on water at increasing light intensities, as did dry and fresh mass of healthy discs. On kinetin, dry and fresh mass also increased with light intensity but hyphal growth decreased slightly. Discs incubated at all light intensities on kinetin had less hyphal growth than those on water at the lowest intensity (<50 lx).Floating leaf discs on chloramphenicol at 500 μ/ml restricted fungal growth but not quite as much as kinetin (10 μ/ml); kinetin inhibited the fungus in the presence of chloramphenicol. Actinomycin D (2.μ5 μ/ml) and puromycin (5.0 μml) had little effect on the fu

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06430.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYIn N. IrelandDiaporthe perniciosaMarch is a common inhabitant of the dead wood of Bramley's Seedling apple trees, and its pycnospores, extruded throughout the growing season, are responsible for fruit infections which result in stalk‐end rots during storage.Pycnidia were produced in culture only after exposure to light, near‐UV radiation being particularly favourable. The carbon source in the medium influenced pycnidia production: high yields were obtained where mannitol was used. Onlya‐spores germinated under the conditions tested, giving optimum germination at 25 d̀C. in a water film. No germination occurred at less than 98% R.H. Germ tubes and hyphae developed appressoria after germination on artificial surfaces but on apple skin most spores produced only a protuberance from which penetration hyphae developed directly. The cuticle and epidermal cells of apples of all ages were penetrated within a few days of inoculation. Intact surfaces and lenticels were penetrated equally. Susceptibility to further rotting increased with age of the fruit. Apples loaded with spores early in the season rotted later than similar apples loaded just before picking. Polygalacturonase was detected in sap expressed from rotted apples of various ages, the level of activity being correlated with the susceptibility of the

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06431.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYCephalosporium maydisinfects young maize plants easily, but as plants age fewer are infected and none after approx. 50 days from sowing. The mesocotyl and seminal, fibrous and adventitious roots are attacked, especially when there is damage or much inoculum. Most penetration occurs where roots are elongating and emerge from the mesocotyl or from fibrous roots. At first the fungus grows superficially on roots, producing hyphae with short, brown, thick‐walled, and swollen cells. After penetrating, the fungus spreads towards the xylem, where it grows slowly at first but after 5 weeks grows faster upwards.C. acremoniumcauses black‐bundle disease of maize. It seems to infect plants growing in unfavourable conditions but the details remain uncertain. The percentage of plants infected was not related to the amount of inoculum and the fungus may not be a primary parasite. The sterile culture filtrate of the fungus produces vascular discoloration and wilt of maize seedli

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06432.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe competitive saprophytic ability (CSA) ofCephalasporium maydiswas smaller at 30 d̀C when measured by the agar‐plate modification than by the original Cambridge method. The agar‐plate method suggested thatC. maydiswas a less competitive saprophyte thanC. acremoniumalthough both were low in CSA.C. acremoniumgrows and sporulates well on organic and synthetic media.C. maydisgrows faster but is more exacting nutritionally and is less able to decompose cellulose or maize straw thanC. acremonium. Neither fungus produced pectolytic culture filtrates and both were susceptible to antibiotics produced by soil micro‐organisms.C. maydissurvived on maize straw much longer thanC. acremonium. In field soilsC. maydiscolonized and survived in supplemented wheat bran poorly and not below the top 20 cm o

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06433.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe relationship between relative survival ability and the number of genes for virulence in two strains ofPuccinia graminis triticiwas investigated using a differential variety to determine the proportion of each race in the mixture. The strain with the widest host range (21 Anz‐2,3,7) became predominant after a number of uredial generations, regardless of its proportion in the original inoculum mixture. However, despite the higher relative survival ability of strain 21 Anz‐2,3,7, strain 21 Anz‐2,7 persisted atc. 1% frequency after four successive uredial generations. The longer the period between successive inoculations, the more rapidly strain 21 Anz‐2,3,7 became predominant in the mixture. The variety on which the mixture was cultured did not influence the relative survival ability of the two

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb06434.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY