13 strains of imperfect fungi have been studied in Lyon according to a biochemical criteria or growth of the studied species in a minimum but nitrogenous medium containing carbon elements. The inoculation is achieved by Api System ensemencement. The germination of the spores showing the carbon assimilation involves the appearance of a trouble. The intensity of this growth is coded by + or -.
The table of the characteristics for the various strains is studied thanks to a taxonomic method based on a relation of proximity by the Euclidean distance. Every strain is represented mathematically by a point in the characteristics-space. The strains are gathered into classes with regard to their proximity, every class being characterized by its centre of gravity. The similar characteristics are studied thanks to a classification tree or dendrogram.
The programme has regrouped the two species pathogenic fungi on the one hand and the ten strains taken in the atmosphere on the other hand, the telluric one having to be set apart.

The area ofPlectranthus fructicosus leaves of different origin and cultivation (seedlings, vegetatively propagated plants from growth chambers with different climates, isolated rooted leaves) fitted in average the equationA=L B k. The coefficientk, however, varies during the ontogenesis of the leaves and the plant according to changes in leaf shape from 0.865 to 0.642.

The development of temporary water stress during the day-light hours, characterized by a decrease of the values of the water potential (ϕ_w) and increase of the values of water saturation deficit (ΔW_sat) was found not only in the leaves of intact kale plants but also in cut leaves with their petioles immersed in water. These results indicate that the leaf resistance to water transport could not be supposed as negligible. The same decrease of ϕ _w was accompanied with the higher increase of ΔW_sat in cut leaves than in leavesin situ.

InBidens bipinnata, a common composite inhabiting mostly gravelly or rocky habitats, two cypsele types are found within a single capitulum. These dimorphic cypsele types differ in their dormancy periods. Evolutionary implications of this differential intracapitular cypsele dormancy are discussed.

A new method of sap flow rate determination in stems of adult trees is described in which mass flow (the transpiration flux in the present case) is estimated from a heat-transfer measurement. The device used includes a couple of thermometers in a differential connection and plate electrodes, through which a controlled heat input flows into a denned studied segment of the xylem. The present method was tested first with a laboratory simulating system, then with the stem of a living adult treePrunus avium L. The data are registered continually and automatically; continuous measurement of sap flow rate of long duration with a greater number of trees is thus made possible.

The successive staining alcian blue/aluminium lake of nuclear fast red was proved a useful tool for studies on plant root tip. A simple and reliable procedure is given resulting in blue cell walls, almost colourless cytoplasm and red nuclei. Attempts were made to apply spectrophotometry and paper chromatography to overcome the confusions in manufacturers' labelling of the dye and to check the lake formation.

In field experiments, the competition among plants of two distinct wheat genotypes in binary mixtures, and among three genotypes being grown in adjacent rows was investigated. The competition greatly affected the over-ground dry weight, weight of stem and grain per plant. This effect was undercompensatory, the depression in poor competitor was higher than the enhancement of strong competitor for all these characteristics. From final components of grain yield per plant, the number of fertile stems and number of grains per ear were more affected than weight per grain. More expressively than weight of grain on the main-stem ear, the weight of grain per average secondary ear-bearing stem was affected by competition in binary mixture. The enhancement in standard height-a strongly competitive genotype- reached in binary mixture about 10% for this last characteristic in comparison with the value from the pure stand. Some morphological characteristics of plants being in relation with competition for grain yield per plant are discussed in these experiments.

The flowering ofSalvia splendensSellow under noninductive short days is promoted by exogenous application of estrogen fraction isolated from flowering sage plants, gibberellin GA₄₊₇ and to some extend N⁶-benzyladenine and estradiol. The most active is the combination of GA₄₊₇ with estrogen fraction. No synergistic action of GA₄₊₇ with N⁶-benzyladenine estradiol was found.

Groundnut (Arachis hypogaea L.) plants were grown for 55 days in dilute nutrient solution at varying concentration of potassium. Data are recorded for the rate of uptake of potassium, magnesium and growth response. Over the concentration range studied, the rate of absorption of potassium followed Michaelis-Menten kinetics with a Michaelis constant (K_m) of 0.06×10^-3M. Identical response curves were observed for either total growth or total uptake. Maximum yield was obtained at a concentration of about 200 μM potassium. Increasing concentrations of potassium depressed the uptake of magnesium.

Growth regulators, indole-3-acetic acid (IAA), gibberellic acid (GA₃), and kinetin (KIN), were used in different concentrations to stimulate the initiation and further development of the fruiting bodies of the fungusLentinus tigrinus. Vegetative mycelium of the fungus was cultivated on cellulose cylinders soaked with a synthetic nutrient solution or with a 3% malt extract. When the mycelium covered the surface of the cylinders, further cultivation was carried out in graduated concentrations of the growth regulators mentioned above. The number of developed fruiting bodies showed that the optimum IAA and GA₃ concentrations were in both media 300 p.p.m. The optimum concentration of kinetin was 400 p.p.m.
The individual growth regulators influenced characteristically also the shape of the fruiting bodies and changed in them the natural level of endogenous growth regulators. The addition of IAA into the medium raised the level of endogenous auxins in the cap. The presence of gibberellic acid and of kinetic in the medium resulted in an increase in the level of these regulators in the fruiting bodies.

Tartaric acid is synthesized on light in the leaves ofTamarindus indica L. and is translocated to the flowers during flowering seasons. The translocation of this acid to fruits keeps peace with their growth rate. The decline of the tartaric acid content per unit fresh weight in mature fruits is not due to their utilization or conversion, but largely due to the setting up of the seeds which are devoid of any tartaric acid. Tartaric acid content in both the leaves and fruits show variation in different seasons, while malic acid does not show any change excepting a small increase in March.

The study deals with the distribution of non-specific esterase in germinating pollen grains ofPortulaca grandiflora. Intense activity of the enzyme is seen in small granules distributed homogeneously in pollen grains stigma hairs and throughout the length of pollen tubes. Further the walls of pollen grains also demonstrate intense activity. The functional significance of the enzyme in these locales has been discussed.

Leaf angles, frequency distribution of leaf area inclinations, leaf area index, amount of intercepted radiation, biological, vegetative and grain yields and grain yield proportion of biological yield were determined in maize stands of two population densities, 55 555 plants ha^-1 (S₁), and 80 000 plants ha^-1 (S₂). Also the effect of the artificial change of leaf angle upon these indices was studied. We classified normal maize stand (N) as the interstage between a planophile and a plagiophile type of canopy, that with artificially changed leaf angle (V) as an erectophile type of canopy. The relative interception of the incoming radiation in the variantsV S₁ andV S₂ was lower than in the variantsN S₁ andN S₂. The variantsV in comparison with variants N increased grain yield and biological yield.

The interaction between exogenous 2-chloroethylphosphonic acid (Ethrel, CEPA) and auxin (both native and synthetic-IAA) was studied on pea and bean seedlings, potato tubers, and processed flax plants. After the addition of ethrel the inhibiting effect of IAA was decreased in all objects and it was found that the concentration of the growth of the regulators played an important role. The growth response of a part of flax hypocotyl, as induced by exogenous auxin produced in the cotyledon, was reversed by ethrel, too. The application of ethrel on the epicotyl apex in beans resulted in the lost of apical dominance of epicotyl and in the growth of lateral buds together with the epicotyl. When stimulating the growth, ethrel reverses the inhibitions through the decrease in the auxin content (from an inhibiting, supraoptimum level to an optimum one which already stimulates growth). In objects with a low content of endogenous auxin the ethrel induced the decrease in the auxin content and shows an inhibiting effect on growth.

Lactate as well as ethanol is formed in seeds of soybean, maize, pea, bean, lentil and broad-bean in the course of germination during the so-called natural anaerobiosis. After 0 to 30 h of germination a concentration peak of lactate appears. Maximum in ethanol content is found after 40 h. The amount of ethanol is higher big more than one order of magnitude as compared to the amount of lactate. Both products of anaerobiosis occur in germinating seeds irrespective of the type of reserve substances.
In contrast to alcohol dehydrogenase lactate dehydrogenase (EC 1. 1. 1. 27) is present in the dry seeds too. Its activity decreases during the first 12 h of germination. It is in this stage that its substrate, lactate, is usually present at a maximal concentration. During the later stages of germination the amount of lactate decreases and enzyme activity rises. There exists a reciprocal relationship between enzyme activity and substrate concentration. In the case of alcohol dehydrogenases (EC 1. 1. 1. 1) the maximum concentration of ethanol precedes the peak of enzyme activity.

The nucleic acid (NA) fractions were analyzed in cotyledons and apical buds ofChenopodium rubrum plants by means of acrylamide electrophoresis at the end of the dark period of a different number of photoperiodic cycles or after transfer of the plants to light for 4 h subsequent to the termination of the dark period. The plants were labelled with³²P three hours prior to sampling. The uptake of³²P into the cotyledons was higher in light than in darkness in all cases, however, it was not in correlation with³²P incorporation into the NA fractions. After one dark period lasting 8 or 16 h NA synthesis in light did not increase in comparison with darkness. After two or more photoperiodic cycles NA synthesis was higher in light than in darkness irrespective of whether the dark period lasted 8 or 16 h. NA synthesis was distinctly highest after two inductive cycles lasting 16 h. In buds NA synthesis was slightly shifted in favour of ribosomal RNA as compared with cotyledons. In the cotyledons the increase in light was mainly duo to a raise of rRNA synthesis whereas in the buds synthesis of sRNA and DNA increased, as well.

An increase in the number of amino acids inAmaranthus viridis plants infected with pigweed mosaic virus was found.

Using starch gel electrophoresis, a group of anodic isoperoxidases which is revealed byo-dianisidine (not by guaïcol) in the soluble fraction of roots proteins from lentil, pea, sugarbeet and maize is never found in corresponding extracts from stems. These root specific peroxidases do not show IAA-oxidase activity as revealed byp-dimethylaminocinnamaldehyde on the gels. They could not serve as a rhizogenesis index since they do not appear from the early beginning of root growth.

The technique of trees production from the undifferentiated poplar callus tissue is described. The best root formation was observed on the modifiedWolter andSkoog medium when NAA in concentration 0.2 to 0.4 mg l^-1 was used as an auxin and cytokinins were omitted. The induction of leafy shoots from the undifferentiated callus was the most effective on the modifiedLinsmaier andSkoog medium in the absence of auxin and with 0.15 to 0.70 mg l^-1 of BAP. The best development of roots at the basal end of excised shoots was achieved when shoots were transferred into the sterile mixture of perlit and sand (3: l, v/v) containing a modifiedWolter andSkoog medium.

Excised stamens ofLilium regale were grownin vitro. From the cut end of the filament a callus is produced and from it several buds and plantlets arise.

Oscillation movements of primary roots of pea seedlings were investigated after low- and high-energy irradiation (10^-2 and 10⁶ W m^-2) which was applied continuously and in pulses at intervals of 3 and 30 min. Oscillation amplitudes of control roots grown in darkness were lower (1 mm) than those of irradiated ones recorded in our previous experiments. The elongation rate of roots grown under scattered and low-energy irradiation as well as their mean oscillation amplitude (2.6 mm) and frequency (8 h) correspond to the standard values recorded in previous experiments. The same effects on root growth and oscillations had scattered electronic flash irradiation.
Side-irradiation did not influence the oscillation movements of growing roots. Their frequency and oscillation amplitudes were not changed. Their longitudal axis was, however, deflected 2.75° from the vertical one due to the negative phototropic response of the root.
The growth oscillations may be, according to present results, interpreted as consequences of tropic growth controlling system. External factors, like irradiation, may influence oscillation parameters,i.e. their amplitudes and after application of side-irradiation also the direction of longitudinal axis of oscillation spirals. The resultant trajectory is composed from movements which resulted from geotropic and phototropic responses of the roots.

Ribonuclease (RNAse) activity was investigated in cotyledons ofChenopodium rubrum plants subjected to various conditions of illumination (photoperiodic induction, continuous light, induction cancelled by interrupting the dark period by a light-break). At the end of the dark period of the single inductive cycles RNAse activity of induced plants was inferior to that of plants grown in continuous light. At the end of the first two cycles the activity was lowest after the interruption of the dark period by light. The investigation of the enzyme in 6h intervals showed rhythmic changes in activity to occur in induced plants. Enzyme activity followed a pattern opposed to this of nucleic acid (NA) synthesis in the cotyledons. In plants from continuous light the enzyme activity did not show any rhythm and in plants having obtained a light-break during the inductive period the rhythm was less distinct than in the induced ones. The period length of the endogenous rhythm of NA synthesis in the cotyledons is about half as long as this of flowering and the peaks of flowering coincide with the throughs of NA synthesis.

The effect of the removal of cotyledons on the growth of etiolated pea plants and on the changes in diamine oxidase activity were followed. Plants with removed cotyledons showed higher diamine oxidase activity both in the shoots and in the roots when expressed per fresh weight unit. Higher diamine oxidase activity can be found also in the remaining cotyledon when one of the two cotyledons is removed (when expressed per fresh weight unit and per cotyledon).
The plants belonging to those experimental variants in which a higher diamine oxidase activity was established (plants without cotyledons) had simultaneously a high content of its substrates. These plants at the same time contained in the shoots and in the roots smaller amounts of potassium. On the other hand, these findings cannot be applied when comparing individual organs (shoots and roots), as higher diamine oxidase activity can be found in the shoots than in the roots, but the content of its substrates is in the shoots lower.
These data indicate that the relationship between the activity of diamine oxidase and the content of its substrates is probably rather complicated. In the connection with the fact that a high diamine oxidase activity can occur in the plant simultaneously with a high content of its substrates, it is possible to assume that (a) changes in the pattern of substrates may occur after the removing of the cotyledons, (b) the synthesis of diamine oxidase may be induced owing to a higher accumulation of substrates, (c) the enzyme may be spacially separated from the substrates in the cells.

Ascorbic acid (AA) turnover, and levels of RNA and protein were determined during germination ofCicer arietinum cv. Chafa under-(i) normal watering; (ii) water stress of six days; and (iii) revival upto next stage of seedling growth after water stress. Water stress lowered significantly AA, ascorbigen, ascorbic acid-macromolecule complex, RNA and protein content in embryo axis while a reverse trend was seen after revival. In the cotyledon, AA, RNA and protein contents were higher during water stress. However on revival only AA and protein contents decreased, whereas the RNA content showed further enhancement. It is suggested that increased synthesis of AA in the cotyledon during water stress may trigger enhanced synthesis of RNA and consequently of enzymic proteins, thus bringing about rapid mobilization of reserve materials during revival.

It has been shown that intensive elongation of wheat coleoptile sections is correlated with indoleacetic acid-1-¹⁴C metabolism. In tissues actively growing the disappearance of indoleacetic acid-1-¹⁴C and formation of conjugates and metabolites (indoleacetamide, indoleacetyl-β-D-glucose, indoleacetyl aspartic acid) is twice as high as in sections where growth has been stopped by physical constraint (plaster) or in tissue which did not elongate by an unknown reason.

Results of the investigation of four isolates of the sour cherry necrotic ringspot virus are presented in this paper. The isolates used caused characteristic symptoms on woody indicators "Bing", "Montmorency", F 12/1, and on peach seedlings. The virus was transmitted mechanically to some herbaceous species:Antirrhinum majus, Cucumis sativus, Cucurbita maxima, Chenopodium quinoa Crotalaria juncea, Momordica balsamina, Petunia hybrida andLeonorus sibiricus. The attempts to transmit the virus mechanically to further 23 herbaceous species were unsuccessful. The thermal inactivation point of the virus lies between 46 and 58°C and the dilution end-point between 10^-1 and 10^-2. The virus is stable in vitro at room temperature for more than one day. Individual virus isolates gave a positive immunological reaction with the Fulton's "G" antiserum.