摘要:

AbstractStachyose, raffinose and sucrose have been tentatively identified in ungerminated Scots pine seeds with paper chromatography and TLC. After the onset of the germination process even glucose and fructose were detected. No free galactose has been found. The occurrence and distribution of starch has been investigated with histochemical technique. The same substances have been quantitatively studied during the first 24 hours of the germination in light and darkness. This was done with an enzymatic technique alone or in combination with TLC. The evidence of a light influence on the transformations of starch, glucose and fructose has been discussed in relation to the phytochrome mechanism.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07397.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractSoluble ribonucleic acid of baker's yeast was fractionated by countercurrent distribution and assayed for both cytokinin activity, using tobacco pith callus tissue, and for certain specific amino‐acid acceptor activities.Two groups of fractions showed cytokinin activity, one of which corresponds to serine and tyrosine transfer ribonucleic acids which are known to contain isopentenyl adenine, while the other corresponds lo undetermined species of ribonucleic acid

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07398.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractSoluble ribonucleic acid of brewer's yeast was fractionated by countercurrent distribution and assayed for certain amino‐acid acceptor activities, as well as for cytokinin activity, using both tobacco pith callus tissue and Scorzonera crown‐gall tissue.An undetermined fraction of ribonucleic acid, rich in cytokinin and similar to one previously reported for baker's yeast, was observed. Two species of cytokinins, probably different from isopentenyl adenine, were detected in other ribonucleic acid fractions by comparing their activities on the two tissues used in growth tests. They do not seem to be located in any of the specific amino‐acid accepting transfer ribonucleic acids determined in this

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07399.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractBesides the standard rod (R) and far‐red (FK) irradiations, a graded series of different R/FR ratios were tested as 10 min terminal exposures at the end of the daily 8‐hour photoperiod of white fluorescent light. Water filtered incandescent light of 3780 lux during 10 min caused A rather weak hut reproducible effect. A superposition to the water layer of different filter combinations shifting the initial transmittance more towards the FR region, and thus gradually lowering the R/FB ratio, resulted in a parallel increase in orthotropic growth and a decrease in chlorophyll content. Our data show growth similarities with the results of other authors on light grown seedlings of higher plants. Rather high levels of the PFRform of phytochrome seem to he required to maintain horizontal growth and optimal chlorophyll content inMarchantiatha

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07400.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractRoots which are turned from their normal direction to directions at various angles with the plumb line develop the largest geotropic curvatures during a subsequent klinostat rotation period when the stimulation angle is well above the horizontal. In experiments with roots ofLepidium sativumL., the optimum is located at 120 to 140° when the stimulation time is between 2 and 15 min. If this fact is to be explained by the movements of amyloplasts in the root cap cells, one would expect roots which bad been kept inverted before the stimulation (so that the moveable amyloplasts are accumulated in the opposite end of the cells) to show an optimum angle well below 90°. — Pre‐inversion of the roots did suppress the curvatures produced by stimulation at angles larger than 90° when measured after 10 to 30 min of klinostat rotation. This suppression may be taken as a support for the starch statolith hypothesis, since the amyloplasts in pre‐inverted roots placed at angles exceeding 90° have a restricted opportunity to slide along the cell walls compared to non‐inverted roots placed at the same angles. In pre‐inverted roots measured after a period of klinostat rotation, however, no optimum was found at angles below 90°. When the stimulation time was 3.75 min, the response curves were nearly symmetrical about 90°. Stimulation for 15 min, on the other hand, resulted in curvatures which were much larger (although suppressed in comparison with non‐inverted roots) when the stimulation angle was 165° than when it was 15°. During the 15 min stimulation period itself, however, pre‐inverted roots curved 0.3° when stimulated at 15, but only 3.4° at 165°. This small difference was very highly significant and is in agreement with the starch statolith hypothesis insofar as the amyloplasts in pre‐inverted roots placed at 15° have the greatest opportunity to slide along the cell walls. The lack of further development (and the actual decrease) of their curvatures during the subsequent klinostat rotation must then be due to other, depressing, factors, summarily designated as tonic. At angles above 90°, the tonic factors are either absent or even enhancing. Tbe tonic effects cannot be expla

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07401.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractGrowth effect of auxin‐amino acid‐conjugates in some test tissues.— Three different amino acid conjugates of the auxin naphthalene‐1‐acetic acid (NAA)‐naphthaleue‐1‐acetyl‐L‐aspartic acid, naphlhalene‐1‐acetyl‐D‐aspartic acid, and naphthalene‐1‐acetyl‐L‐glutamic acid — have been prepared and tested for growth stimulation in tobacco callus tissues, sunflower hypocotyls, and wheat coleoptiles. All conjugates show less auxin activities than NAA. The ratios of concentrations for more or less the same growth stimulation are 1:25 to 1:100 and less. Each test tissue grows the least on the D‐aspartic acid conjugate. These results lend to the conclusion that growth stimulation by these conjugates has lo be an indirect one, probably due to their hydrolysis generating free auxins. It is unknown whether the hydrolysis

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07402.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractIndole, α‐ and β‐naphtol are synergistic with auxins in enhancing root production of cuttings ofPhaseolus vulgaris.To find an explanation for this synergism the activity was compared with that of phenolic compounds which are known to be:a. inhibitors of the IAA oxidase system,b. cofactors of the conversion of tryptophane to IAA.Both processes appeared to occur in the bean cuttings (as estimated by root production), but none of the phenols bad an activity equally strong as the “synergists”.It is suggested that indole as well as α‐ and β‐naphtol act as other injurious substances in “just sublethal” d

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07403.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractPairs of nutsedge plants connected by rhizomes were planted, each in a separate pan, without cutting the rhizomes. One plant within each pair was treated with 5.7 kg of dicamba per hectare seven days later. Ten days after treatment, the treated plants and those plants attached to them by rhizomes were harvested separately and analyzed by gas chromatography. The attached plants were found to contain 6 per cent as much dicamba as did the directly treated plants. The suspected metabolites, 3,6‐dicblorosalicylic acid, 3,6‐dicblorogentisic acid and 5‐HO‐dicamba, were not d

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07404.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractUnequal two shoot systems of tall and dwarf varieties ofPisum sativumL. ev, Improved Pilot and Meteor, respectively, were used in experiments where manipulative treatments involving the removal of one or other or both of the shoot apices were carried out. These were combined with GA treatments. Twenty four hours after treatment,14CO2was applied to the lowest expanded leaf on the larger shoot, and the distribution of radioactivity was determined after a further 24 hours. Removal ot the apex of the larger shoot reduced the level of translocation from the treated leaf, the effect being enhanced by the additional removal of the other apex. This (Heel was more marked in the tall than in the dwarf variety.In untreated control plants of both varieties there was very little transfer ot labelled material from the larger (dominant) shoot to the smaller (weaker) shoot. This pattern was not affected by the removal of the apex from the weaker shoot. In Improved Pilot, removal of the apex from the stronger shoot led to considerable transfer of radioactive material to the weaker shoot, GA treatment having little effect. However, in Meteor, transfer of radioactivity from the stronger to the weaker shoot. after removal of the apex from the stronger shoot, only occurred after the application of GA. Removal of both shoot apices again resulted in low levels of transfer of labelled material to the weaker shoot in both varieties.These results are consistent with the hypothesis that there is competition between the two shoots for photosynthates produced by the leaves and that treatments reducing the competitive ability of one shoot, reduce the level of nutrients received by that shoot and can result in transfer of materials from it to the other shoot. Continuation of such a situation will result in increased inequality and perhaps ultimately in the death of the weaker shoot.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07405.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractChlorella pyrenoidosahas been cultivated in radiation of wavelengths between 690–975 nm for several months. Absorption spectra and action spectra of photo‐synthesis have been determined for far red and “white” light brown cultures,In vivospectrophotometric analyses and action spectra showed that fur red growth Chlorella adapted to the extreme light conditions by an increase both in absorption and photosynthesis above 700 nm. It is proposed that som of thein vivonormal chlorophyll a forms were converted to a far red absorbing chlorophyll a form, giving the far red exposed suspension an increased photosynthetic activity between 700–740 nm. The analyses of far red grown Chlorella have also shown an increased photosynthesis in the blue part of the spectrum, presumably due to a decrease in photosynthetically inactive carotenoid content. By culturing Chlorella in a “white” light gradient between 0.5 × 104and 3.7 × 104erg cm−2s−1, it has been demonstrated that light intensity did not influence pigment ratios between 500–750 nm. In the blue part, however, high light levels caused increased absorption because of increased carotenoid content. Some ecological aspects of this far red effect hav

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1969.tb07406.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY