Karyotypes ofAllium fistulosum, A. altaicum andA. cepa cv. Karmen are described and protein patterns of their seeds determined by immunoelectrophoresis are compared. Esterase isoenzymes were evaluated by polyacrylamide gel electrophoresis and isoelectrofocusing. Karyological and chemotaxonomical analysis confirmed thatA. fistulosum andA. altaicum are closely related and both species are taxonomieally distant fromA. cepa cv. Karmen.

Needle primordia were isolated from embryonic shoot expiants of 88 year oldPicea abies (Norway spruce) in order to develop a method for micropropagation using adult mother trees. The isolation of needle primordia in combination with frequent subculture, stimulated the formation of peripheral meristematic tissue in expiants cultured on a modified Murashige & Skoog medium supplemented with cytokinin. Transfer of isolated needle primordia with peripheral meristematic tissue to medium without growth regulators, and with a reduced ratio of NH+4/ NO-3, resulted in the formation of adventitious buds.

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.

Petunia hybrida plants were inoculated with differentAgrobacterium rhizogenes andA. tumefaciens strains and developed tumors were further cultivatedin vitro. Transformed flowering plants differentiated from tumors induced byA. rhizogenes strains 8196 and TRIOL Transformed but non-rooted plants developed also from tumors incited byA. tumefaciens T37. Cultures of roots transformed byA. rhizogenes strain 15834 did not show increased incidence of chromosomal aberrations in anaphases in comparison with untransformecl control. Permanent growth of isolated untransformedPetunia roots was not induced by addition of IAA into the medium.

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.

With the aim to reduce the period of flowering and of fruit maturation, we investigated the effect of auxins on flower formation. For these experiments we used young decapitated plants with two plagiotropic branches. Both the auxins, indol-3-ylacetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D), retarded flower formation in coffee, the latter one being more effective. The effects of 2,4-D if applied on only one of the two plagiotropic branches can be observed only in this treated one. Furthermore, the auxins seem to act in coffee plant directly by affecting flower formation and not indirectly by inducing endogenous ethylene production.

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.

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.

Manipulations of production systems in rubber tree which were intended to improve sucrose translocation in tapped bark resulted in an increase of latex sucrose and of latex production and reduced the incidence of nonyielding laticiferous tissue. This was achieved by shortening the tapping cut from full to half spiral, by changing the descending direction into an ascending mode of tapping or by annual change-over of tapping panel allowing for a longer time the regeneration of bark removed above the location of the cut. The increase of latex yield did not result in a significant decrease in the growth of trees over a period of three years.
Clonal differences in nonyielding bark appeared to be related to differences in sucrose depletion by tapping. In clone PB 235 which exhibited low latex sucrose, a reduction of tapping frequency resulted in an increase in sucrose level and in a decrease of bark "dryness" tending to an increase in total yield.
The tapping manipulations examined did not affect latex flow characteristics such as the plugging index of latex vessels and the bursting index of lutoids. The results stress the importance of photosynthate allocation for the physiology of laticiferous system productivity and indicate the possibilities of improving assimilate economy in rubber trees.

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.

The carbon balances of whole, 21-d old French bean plants (Phaseolus vulgaris L.) grown in standard nutrient solution (1K) and its modifications without (OK) or surplus (2K) potassium were calculated from the daily photosynthetic carbon inputs of individual leaves, and the daily respiratory carbon losses by individual leaves, stalks and petioles, and roots. Under the three K concentrations, maximum net photosynthetic rates (P_n) were found in the 2nd or in the 3rd trifoliate leaves, maximum respiratory rates (R_d) in the youngest, 4th trifoliate leaves; the P_n/R_d ratio decreased with leaf age. In all leaves of 2K plants, leaf dry masses and thicknesses, P_n, P_n/P_d ratios, and stomatal and intracellular conductances were lower than in OK and IK plants. Daily whole-plant net carbon gain was highest in IK plants, whereas in OK and 2K plants it was 98.0 and 81.3 % of IK, respectively. Similar values were found in the parameters of growth analysis, namely in net assimilation rates and relative growth rates.
No differences were found in water potential (Ψ _w ) or water saturation deficit (W_sat) in the OK, 1K and 2K plants sufficiently supplied with water or during wilting and resaturation. The decrease in Ψ_w to -0.97 MPa was associated with a 19.9 %, 31.4 % and 23.4 % decrease in P_n of OK, 1K and 2K plants, respectively, but no effect on R_d was found. In the three variants, the short-time effect of mild water stress was fully reversible.