Fertilizer induced improvement of growth and yield of wheat (Triticum aestivum L. cv. Kalyan Sona), under salinity stress, was associated with an increase in the concentrations of nitrogen, phosphorus and potassium and a decrease in the level of chloride in the tissue. The concentration of chloride in grains was also reduced under high fertility as compared to low fertility condition. Results reveal that under both normal and saline conditions, nutritional improvement leads to higher chlorophyll concentration and increased efficiency of enzymes like nitrate reductase, ATPase, alkaline pyrophosphatase and amylase in the leaves. This imparts importance to fertilizer application under saline conditions.

Barium chloride at 0.1 mM concentration inhibited elongation of mungbean (Phaseolus aureus) roots more strongly than elongation of hypocotyls. Root growth was completely inhibited at 80 mM and there was no germination at 100 mM. Respiration rates which were directly proportional to seedling vigour declined at varying degrees at the growth-inhibitory concentrations of BaCl₂. Barium retarded senescence in isolated leaf discs ofCephalandra indica by maintaining the chlorophyll level in darkness. The carotenes were similarly protected from degradation by Ba in darkness whereas xanthophylls were retained both in darkness and light. Ba also protected anthocyanin pigments in the staminode discs ofCanna indica flowers and reduced to a variable extent the leakage of betacyanin pigment fromBeta vulgaris root discs caused by various membrane active chemicals. Applied either alone or in combination with IAA, Ba inhibited cell enlargement in wheat (Triticum aestivum) coleoptile sections. Barium-induced inhibition of lettuce (Lactuca sativa) hypocotyl elongation was largely overcome by GA₃.

The effect of high concentrations of the simplest polyphenols on extension growth of maize (Zea mays L.) shoot ooleoptile segments, lettuce (Lactuca sativa L.) roots, and on radish (Raphanus sativus L.) seed germination, was studied. Quinone formation in the process of plant incubation in polyphenol solutions was proved. The data obtained are presumably explained by the important part that is played by the quinoid products of phenol oxidation in the ability ofo- andp-biatomic phenols to inhibit growth.

Chlorflurenol (morphactin) EMD 7301 W (60, 120 and 240 mg I^-1) when applied at five to seven leaf and 10-12 leaf stage induced hermaphrodite flowers in the inflorescences ofRicinus communis. The hermaphrodite flowers were mostly apical in position unlike the apical female flower in the control. With an increase in the time gap between sowing and emergence of the inflorescence there was a reduction of the female structures in the hermaphrodite flowers. The last formed inflorescences had an apical male flower in place of a female. The largest number of inflorescences with an apical male or hermaphrodite flower were produced with 60 mg 1^-1 applied at five to seven leaf stage. The hermaphrodite flowers failed to set fruits.

Preparations of total DNA isolated from algal cells ofChlamydomonas geitleri were characterized by routine methods (UV-spectra, thermal denaturation, sedimentation analysis, centrifugation in CsCl density gradients). In this way, the fundamental physicochemical characteristics, undetermined for this alga up to now, have been attained.
The comparison of the characteristics of the preparations of DNA showed that during isolation it was more convenient to prefer procedures that use the lysis of cells. A mechanical disintegration may sometimes lead to the degradation of the macromolecules of DNA.
The ascertained characteristics of DNA in the alga under study are compared here with the corresponding values of DNA known for the most widely studied volvocal algaChlamydomonas reinhardii as well as for other species of green algae. The greatest difference between the two species comparcd was in the contents of bases G + C. The determined values inChlamydomonas geitleri from 43.4 to 45.4 mol.% are much lower than the values known inChlamydomonas reinhardii (about 65.5 mol.%) or those published for some volvocal algae (60 to 68 mol.%).

The adaptation of Marmur's method, suitable for DNA isolation from plant cell culture, is described.

The effect of nystatin on the fresh-water algaHydrodictyon reticulatum was studied by estimating the electrical resistance of both the membranes and the intracellular fluid. The outflow of potassium ions into the external medium, occurring after addition of nystatin, was determined by flame photometry.
Values of ohmic resistance of membranes treated with nystatin ranged from 0.33 to 1.51 kΩcm², the control values being 8.03-16.73 kΩcm². Values of the resistance of intracellular fluid in nystatin-treated cells lay in the range of 3.21-7.13 kΩcm, those of control cells being 1.10 to 1.91 kΩcm.
The concentration of potassium ions in the external medium increased from 1.35 mM to 4.3 mM after addition of nystatin.

The effects of different osmotic stresses (from 0 to -8× 10⁵ Pa) obtained with NaC or polyethylene glycol 6000 solutions on the germination of flax, sesame and onion seeds were investigated. The effect of presoaking with gibberellic acid (GA³) on the germination of the above mentioned seeds was also studied.
It was found that the rate of seed germination and the final germination percentages as well as the amount of water absorbed by the seeds were considerably lowered with the rise of osmotic stress levels whatever the stress agent used, more considerable reduction was obtained under polyethylene glycol 6000 than under NaCl.
Presoaking with gibberellic acid increased the rate and the final germination percentage of osmotically stressed flax and sesame seeds, while those of stressed onion seeds were slightly retarded.

Chloramphenicol has been found to inhibit nitrate reductase activity in black-gram leaves. It inhibitsin vivo nitrate reductase activity up to 50-67%, and the catalytic property of the enzyme up to a maximum of 70-98%. Modulators, such as KNO₃, NADH and HCO₃ could not protect enzyme inhibition by chloramphenicol. It is suggested that the chloramphenicol inhibition is mainly through its effect on the catalytic process of the enzyme.

The radial transport of organic nitrogen compounds was studied in maize seedling roots in relation to the metabolism of uniformly labelled¹⁴C-amino acids (alanine, arginine, dicarboxylic amino acids and their amides) in the cortex zone. Most active metabolism accompanying transport to the stele was observed for¹⁴C-glutamic acid of "primary" amino acids and for¹⁴C-glutamine of "reserve" nitrogen sources. The transport of¹⁴C-asparagine and¹⁴C-arginine to the conducting bundles is accompanied by weak metabolism. A distinguishing feature of nitrogen metabolism in the stele is intensive decarboxylation of glutamic acid, formed in the course of radial transport and metabolism, to gamma-amino butyric acid. This process is assisted by a highly active glutamate decarboxylase present in the conducting bundles.

The nutational movements performed by the leaves of the "Sensitive plant",Mimosa pudica L., result from periodical turgor variations taking place in the parenchymatous cells of specialized motor organs. The trajectories in the three kinds of leaf motor organs usually show irregular elliptical paths with a period ranging from 10 to 60 min. The morphological analogy of these turgor movements is discussed in relation to nutational movements observed in growing organs.

Starch formation was studied by means of plant anatomy in segments of maize and pea leaves, deprived of starch, floating overnight in the dark (1) on solutions of various saccharides, (2) on sucrose solutions containing auxin-type growth regulators and (3) on suorose solutions with antibiotios (proteosynthesis inhibitors). A comparison was made of mesophyll tissues of the two species used, of spongy and palisade parenchyma in pea leaves and-especially-of mesophyll and vascular bundle sheath in the leaves of maize. Although the effects of the given treatments were striking, the response of the particular tissues was considerably uniform. If the given sugar appeared as utilizable for starch formation, it was effective equally in all tissues under study. It was not possible to distinguishin situ the different ways of staroh synthesis by means of the application of growth substanoes. No striking differences in the effect of antibiotics upon staroh formation were seen in-normally-starch containing and starch lacking tissues.

The plant growth regulator 2-ohloroethylphosphonic acid inhibited the elongation of growth inPhaseolus aureus seedlings. In comparison to the control, the polyphenol oxidase and peroxidase activity of treated seedlings was low up to 24 and 48 h of germination, respectively and that of phenylalanine ammonia-lyase and tyrosine ammonia-lyase was slightly less at 120 h and that of α- and β-glucosidases were less at 48 and 72 h, respectively. At other stages of germination, it greatly stimulated the activities of these enzymes.

The reversal of the cytogenetic effects of 5-fluordeoxyuridine, which are the gradual decrease of the mitotic index and the induction of chromosomal fragments was followed after addition of different concentrations of thymidine. Thymidine in the concentration 10⁴ M reversed both the effects of FUdR completely. The concentration of thymidine 10⁵ M partly reversed both the decrease of the mitotic index and the induction of chromosomal fragments. Uridine also caused some decrease of the cytogenetic effects of 5-fluordeoxyuridine.

FUdR 10^-4 M was applied together with [³H] TdR on the growing barley embryos cultivated in the nutrient solution. Samples were fixed 1-4 h after the onset of the treatment and microautoradiograms were prepared. All the mitoses were unlabelled, while more than 150 autoradiographic grains were found above labelled interphase nuclei; no cells that terminated S phase at the onset of the treatment passed through entire G₂ and reached mitosis during the 4 h duration of the treatment. Chromosomal fragments in anaphases appeared the first hour after the onset of the treatment. Their frequency increased from the first to the second hour and remained almost constant from the second to the fourth hour. FUdR induces chromosomal fragments in barley root meristems also in G₂ phase of the mitotic cycle.

Fifteen soybean cultivars were evaluated in two water supply conditions, inducing or not a drought stress. Main canopy traits were measured several times during the reproductive period and, at maturity date, the yield components were estimated. Using principal components analysis, the main physiological functions involved in soybean drought tolerance are described: leaf cells enlargement and assimilates transport. These processes could be a good basis on which to define new selection criteria for soybean drought tolerance.

Four soybean cultivars differing in storage potential were subjected to accelerated aging for different periods (2, 4, 6 and 8 days) and tested for germinability and beta-amylase activity. Aging caused a considerable and continuous increase in enzyme activity in both cotyledons and axes of all the four cultivars.

Two isolectins were isolated from the albumin fraction ofArtocarpus integrifolia L. seeds, by precipitation with ammonium sulfate, and DEAE-cellulose and SP-Sephadex C-50 chromatography. The isolectins, when passed through Sephadex G-100 at pH 7.4, had a molecular mass of 43 000 and when subjected to SDS electrophoresis in the presence of β-mercaptoethanol consisted of two subunits with molecular mass of 11 250 and 15 000. When they were tested with human erythrocytes of all the groups of the ABO system there was no blood specificity. The isolectins formed interference arcs by Ouchterlony double diffusion in agarose gel.