Genotypes of mustard (B. juncea) were evaluated for concurrent changes in leaf water potential (Ψ), leaf osmotic potential (π), leaf turgor potential (P) and leaf relative water content (RWC) during moisture stress at reproductive stage of growth. The slope 'b' in the regression between Ψ and π varied from 0.43 to 0.97 and was positively correlated with P and RWC. The genotypes with 'b' around 0.7 were able to maintain P of about 0.5 MPa at Ψ of - 2.5 MPa and thus such value of 'b' seems to provide enough degree of tolerance against drought.

Growth and ionic relations were studied in six triticale cultivars of different geographical origins grown in a greenhouse in nutrient solution with or without the addition of 100 mM NaCl. In 21 d old plants of all the six cultivars growth was little affected in the salt treatment, whereas in the subsequent three harvests during vegetative phase (after 31, 38 and 45 d), growth reduction effects of salinity were progressively pronounced. Generally, shoots of all the six cultivars accumulated relatively more K+ as compared to Na+ or Cl-. Differential accumulation of K+, Na+ and Cl- by various cultivars was coupled with variable rates of Na+ and Cl- transport from root to shoot which were - to some extent- related to cultivar differences in growth in saline root media. Chloride content of shoots of the six cultivars was negatively correlated with the relative growth reduction due to salinity at the four harvests.

All the concentrations (25-150 mgl-¹) of the phytohormones kinetin, IAA (indol-3-ylacetic acid) and GA₃ (gibberellic acid) increased the activity of DCPIP (2,6 dichlorophenolindophenol)-Hill reaction, chlorophyll and protein contents over the control data in leaves ofSechium edule Sw. on Darjeeling hill of the Eastern Himalayas; while ethrel (2-chloroethylphosphonic acid) treatments decreased these parameters in the hilly species. The most effective concentrations in increasing these parameters were 50 mg 1-¹ of kinetin, 50 mg 1-¹ of IAA and 100 mg 1-¹ of GA₃; whereas 50 mg 1-¹ of ethrel was most effective in decreasing these parameters during the induction of senescence in the hilly vegetable crop. The increase in these parameters was greatest with kinetin, followed by IAA and least with GA₃ in the hilly plant species studied.

The effect of the glucoainolate sinigrin applied at concentrations from 5×10^-6 to 5 × 10^-3 g cm^-3 on the infectivity of two isolates of turnip mosaic virus (TuMV) was studied. A statistically highly significant linear correlation relationship was found between the concentration of sinigrin added to the sap prepared from infectious plants ofPetunia hybrida hort. Vilm. cv. Lavina and the infectivity of the virus, expressed in the number of local necrotic lesions onNicotiana tabacum L. cv. Samsun leaves. Sinigrin caused a statistically significant decrease in the virus infectivity already at a concentration of 5 × 10^-5 g cm^-3. This virocidal effect of sinigrin was not dependent on the virus isolate applied and was not influenced by the host plantsP. hybrida andNicotiana glutinosa L. A statistically highly significant decrease in the virus infectivity was also caused by sinigrin applied at a concentration of 5 × 10^-3 g cm^-3 in the sap from infectiousSinapis alba L. andBrassica nigra (L.) Koch plants, in which case its enzymic degradation to allyl isothiocyanate was observed. When these plants were homogenized in 0.5 M phosphate buffer pH 8.5, no statistically significant decrease in the infectivity of the virus was observed. Purified virus preparations in 0.5 M phosphate buffer pH 7.5 were not affected by sinigrin applied at the concentration of 5 × 10^-3 g cm^-3. The significance of the content of glucosinolates in the pathophysiology of theBrassicaceae and in their resistance to viruses and other pathogens is discussed.

Recurrent application (17 administrations in 38 days) of 14 pesticides (Karathane FN 57, Fundazol 50 WP, Dithane M 45, Topsin M 70 WP, Perozin 75 B, Fademorf EK 20, Novozir MN 80, Metation E 50, Pirimor DP, Decemtion EK 20, Zeazin 50 DP, Fatex EK 80, maleic hydrazide and Ethrel) did not increase (with the exception of maleic hydrazide) the frequency of somatic mutations in a heterozygous chlorophyll mutant ofNicotiana tabacumL. var.xanthi n. c. None of the four tested pesticides (Fademorf EK 20, Decemtion EK 20, maleic hydrazide and Ethrel) were transformed in tobacco plants to a stable mutagenic or promutagenic product active in theSalmonella (Ames) mutagenicity assay.

White light suppressed the stem growth and promoted leaf expansion. With increased irradiance the light effect was enhanced. The morphogenetic effects induced by light and by dwarf-mutation are similar. However, the nature of phenotyplc and genotyplc dwarfism is different. In the dwarf mutants the auxin level is not changed in contrast to the GA, ABA and QGC contents. Under high irradiance which depressed the stem growth, auxin and GA-levels were lowered while the content of QGC and of growth-inhibitor non-identical with ABA increased, but the level of ABA was not affected. The sensitivity of various pea forms to the light and to exogenous phytohormones (GA and IAA) is different. The plants with the shortest stems were more sensitive to light and GA. Data on the stem growth and rhizogenesis induced by light and by GA are presented. The metabolism of 2-¹⁴C-PCA (precursor of QGC) in tall and dwarf forms is different. The possible role of phytohormones and some phenolic compounds in the regulation of growth and morphogenesis of phenotyplc and genotyplc dwarf forms is discussed.

Primary explants from the inflorescence stem of tobacco and primary explants from the stem of vegetative plants, cultivatedin vitro under the same conditions, display different morphogenetic ability. The former give rise mostly to floral buds, whereas the latter exclusively to vegetative ones. Histological and histochemical analyses of both original andin vitro cultivated explants were made. They showed differences in chlorophyll content and alcohol dehydrogenase (AD) activity of the original explants reflecting their different metabolic status. Bud primordia were initiated in the superficial meristematic layer derived from epidermal tissues. Floral or prefloral apices were characterized by a strong AD activity in all cells of the meristem, while in vegetative apices AD activity was restricted to their uppermost parts. A high rate of procambium differentiation connected with leaf primordia formation was typical of vegetative buds. A higher concentration of glucose (5 %) enhanced cell division in explants, which is also correlated with a higher AD activity. The significance of vascular tissues for differentiation of vegetative buds is discussed.

The caryotype (2n = 24) of crownvetch (Coronilla varia L.) and the conditions of successful cultivation of tissue cultures derived from it were determined. The Murashige-Skoog cultivation medium with the addition of indol-3-ylacetic acid (1 mg 1¹), 1-naphthaleneacetic acid (0.1 mg 1¹), or coconut milk (20 %) was found to be the most suitable. A complex of cardenolide-like substances identical in its composition with that found in leaves of intact crownvetch plants was detected by means of thin layer chromatography in the extracts of these explant cultures up to the seventh subculture. These findings are also in agreement with the results of our earlier experiments in which strong pharmacological effects of cardenolides obtained from tissue cultures of this plant were demonstrated. Further investigations must be devoted to the optimalization of cultivation conditions of crownvetch cultures with the aim of their utilization as anin vitro source of cardioactive substances.

The mature nodules ofPhaseolus aureus Roxb. var.mungo possessed, in comparison with young and old nodules, higher activities of nitrogenase (N_2ase), and indol-3-ylacetic acid (IAA) metabolic enzymes like IAA oxidase, methylene oxindole reductase and peroxidase; higher levels of IAA-like, gibberellic acid-like (GA), and cytokinin-like (CK) substances and tryptophan, and lower level of phenol. The abscisic acid-like (ABA) substance level was higher in the old nodules.
The N_2ase activity in the mature nodules changed parallelly with IAA and OK. butoppositely with GA and ABA. The changes in tryptophan level, IAA oxidizing enzymes, and phenol metabolism controlled the IAA level in the nodules.
The nodules developed similarly throughout the year, but they had variable hormone levels in different seasons. This indicated that the formation and growth of the nodules was controlled not only by the nodular hormones.

This paper describes the successful selection of plant cell var ants with differing secondary substance productions by means of an adsorbent filter method. The method allows a simultaneous screening of up to 100 small cell aggregates per Petri dish within short time.

The herbicide terbutryn induced up to 11.3 % chromosomal abnormalities in cells undergoing meiosis inVicia faba. The mean number of pods/plant and the mean number of seeds/pod were considerably reduced, but the average seed dry mass was not or was only slightly affected by this herbicide. In C₂ plants chromosomal abnormalities were observed in few but significant numbers of cells.

Uptake and loss of irorganic phosphate was determined in sweet potato slices 'aged' in the presence or absence of gibberellic acid. Concentrations of uptake medium were varied from 0.1 to 1.2 mM. Slices, aged in gibberellic acid, took up considerably less phosphate, at all concentrations than control, whereas efflux from GA₃ treated discs was greater than control. Whether treated or untreated, kinetics proved to be biphasic hyperbolas. The results suggested an alteration in membrane permeability induced by gibberellic acid.

Kanamycin resistance gene was introduced into tobacco and Atropa belladonna cells by binary vectors, based on Agrobacterium, by means of inoculation of seedlings. The plasmid pGA472, which carries chimaeric kanamycin resistance gene expressed in plants was introduced by transformation into A. tumefaciens Bo542, harbouring pTiBo542 plasmid and A. rhizogenes 8196, carrying pRi8196 plasmids and the resulting two strains were used as binary vectors. Tobacco tumors induced by A. tumefaciens Bo542(pGA472) grew as undifferentiated, kanamycin resistant tissues. Those induced by A. rhizogenes 8196(pGA472) differentiated into transformed plants. When cultivated in vitro on 200 μg ml^-1 kanamycin medium, they showed yellow green sectoring, which was not selected out during vegetative propagation. Atropa belladonna tissues transformed by both A. tumefaciens Bo542(pGA472) and A. rhizogenes 8196(pGA472) differentiated plants which grew well on 200 μg ml^-1 kanamycin as green, non-sectoring plants; sensitive cells obviously did not divide at all. Selection of Atropa belladonna transformed tissues on kanamycin medium is much more efficient than selection of transformed tobacco tissues with introduced kanamycin resistance gene.

High irradiance during treatment of mung bean cuttings favours root formation in response to supplied auxin, whether the latter is IAA or IBA. On the other hand it is inhibitory towards root formation in the absence of supplied auxin. Light promotes the uptake of¹⁴C-IAA into cuttings and its upward movement into the leaves. When¹⁴C-IAA is applied to leaves of cuttings high irradiance favours movement of radioactivity into the epicotyl and hypocotyl. This movement is also enhanced by concomitant supply of IBA to the base of the cuttings. The irradiance under which stock plants are raised also affects the extent of root formation on cuttings. When cuttings are held in darkness without a supply of exogenous auxin they root best if prepared from seedlings raised under high irradiance. However, transport of¹⁴C-IAA out of leaves of cuttings is favoured when cuttings are prepared from seedlings grown under low irradiance. These observations are discussed in relation to auxin transport, photodestruction and, possibly, metabolism.

Relationships among storage proteins in seeds from cultivars and primitive accessions of the four economically most important species ofPhaseolus - P. vulgaris, P. coccineus, P. acutifolius andP. lunatus - were studied.
Analysis of SDS-polyacrylamide gel electrophoretic patterns of storage seed proteins revealed common characteristics in the major groups of polypeptides forP. vulgaris, P. coccineus andP. acutifolius, while clear differences existed between thesePhaseolus species and P.lunatus.

An auxin binding protein fraction prepared by means of affinity chromatography on 2-OH-3,5-diiodobenzoic acid-Sepharose and gel filtration was used as antigen. The obtained rabbit antisera contained antibodies against the auxin, binding protein (ABP) and several contaminating proteins (nonABP). The nonABP could be separated on an appropriate affinity matrix omitting the TIBA analogue. After their immobilization on Sepharose antibodies directed towards contaminating, the proteins were isolated and immobilized, too. This IgGanti nonABP-Sepharose retains almost all contaminating proteins present in the specific eluates of the auxin affinity matrix. In a final affinity chromatography step on IgG-Sepharose a highly purified ABP could be eluted. This ABP was immobilized on Sepharose for the separation of monospecific antibodies against ABP (IgGanti abp). Using these antibodies the ABP could be localized within the outer epidermal cells of the coleoptile by immunofluorescence microscopy. From the inhibition of auxin induced elongation of coleoptile tissue by IgGanti abp it is concluded that the ABP is localized at the plasmalemma of the epidermal cells and that the ABP is involved in auxin action as a true hormone receptor.

Ultrastructural changes following increasing periods of water stress induced by means of polyethylene glycol 4000 (from 5 min to 18 h) were investigated in young epidermal cells of the primary roots ofZea mays. The sensitivity of the individual cell components to water stress was considered according to the time sequence in which their alterations appeared.
Endoplasmic reticulum (ER) and mitochondria proved to be the most sensitive cell components, their structure changing after 5 min of water stress. By 8 h of stress, the condensation of nuclear chromatin in some cells was apparent, preceding polyribosome degradation but not all the other changes of the stressed cells. Similar types of structural alterations appeared slightly earlier in the more differentiated epidermal cells. The rapid changes in the structure of ER and mitochondria coincided with the rapid decrease of water potential of the root tips and the immediate cessation of the root growth.

Distant hybridization of several species of the genusAllium was performed. It was found that disharmony of the time of flowering of the parents may be overcome by storage of pollen ofA. fistulosum at 40 % humidity and 0 °C. Protein patterns of parents and F₁ hybrids were compared using immunoelectrophoresis, esterase isoenzymes were evaluated by electrophoresis in polyacrylamide gel and isoelectrofocusing. Parents and relevant hybrids differ from each other. Certain differences were found between reciprocal hybrids.

The effect of CCC treatment on the GA and IAA contents of the hypocotyls of green and etiolated bean plants and on their distribution was studied. In the treated plants the GA content of the hypocotyls was higher than that of the control. On the application of CCC the distribution of the hormone content within the organ altered: in the basal part of the hypocotyls of the treated plants the hormone content increased. In the hypocotyls of the treated plants the IAA content was less than in the controls and it was accumulated in the basal part. The ethylene production of the aplcal and basal parts of the hypocotyls proved to be correlated with their IAA content.

Phenolic compounds l,2,3-trihydroxy-5-methoxyxanthone, l-hydroxy-3,5,6,7, 8-pentamethoxyxanthone, and l,8-dihydroxy-2,3,4,6-tetramethoxyxanthone predominate in the callus tissue ofCentaurium erythraea, their content increasing with culture age. By contrast, the contents of the derivatives of cinnamic, chlorogenic, and ferulic acids decrease or do not change. In the cell suspension culture ofC. erythraea a larger amount of xanthones is synthesized than in the callus from which the suspension culture was derived. The content of phenolic acids is lower in the suspension culture than in the callus, but a larger number of low-molecular-mass phenolic substances occurs in the suspension culture than in the callus tissue.

Electrophoretic separations of soluble proteins extracted from crown-gall tumors, normal calli, and leavesof Nicotiana plumbaginifolia were performed in order to detect pathogenic changes caused byAgrobacterium tumefaciens transformation. These analyses showed the appearance of new low-molecular polypeptides both in crown-gall tumors and in normal calli. The SDS-polyacrylamide gel electrophoresis as well as the gel electrophoresis in non-denaturing conditions were used to characterize their properties. At least some of them corresponded to the pathogenesis-related proteins reported inN. tabacum. Isoenzyme patterns of peroxidases and esterases also revealed a higher number and a deeper staining density of isoenzyrnes in crown-gall clones and normal calli compared with leaves, thus indicating an increased activity of enzymes in thesein vitro cultivated tissues.