Study of electrophoretic variability in Epipactis helleborine (L.) Crantz,E. palustris (L.) Crantz and E. microphylla (Ehrh.) Swartz (fam. Orchidaceae)

Allozymic variation in seven enzymes coded by eight loci was studied in seven populations of terrestrial Epipactis orchids, including four populations of E. helleborine, one population of E. palustris and two of E. microphylla, from Latium (Central Italy).Heterozygosity estimates reveal that E. helleborine (EH) is the most variable species (HET=0.233; P=0.59; A=1.8), followed by E. palustris (EP) (HET=0.085; P=0.29; A=1.3) while E. microphylla (EM) is monomorphic for all the loci examined.It is suggested that the two EM populations examined, with a total lack of genetic variability, could originate from the same genetically impoverished ancestral population. Also the low variability amount of EP can be ascribed to genetic drift, probably due to a founder event.Nei's identity coefficients were also calculated. These show a high similarity in EH (=0.987) and EM (=1.000) populations. Average identity value between EP and EM is 0.289, between EP and EH is 0.336 and between EM and EH is 0.784. These data reveal that E. palustris presents a remarkable genetic, besides geographical and ecological, differentiation.     

诸葛菜茎叶中黄酮类化合物的研究

诸葛菜茎叶乙醇提取物用Ｍｇ＋ＨＣｌ,Ｚｎ＋ＨＣｌ,１％ＦｅＣｌ３－乙醇液,１％ＮａＯＨ进行显色反应,呈现黄酮类化合物性质特征颜色。又以槲皮素,山柰酚,异鼠李素为对照品,采用ＨＰＬＣ法分析测定了其茎叶中黄酮醇的含量。结果表明干品中总黄酮含量（以甙元计）为０．５６８％。     

THE EFFECT OF BORON DEFICIENCY ON CALLOSE FORMATION AND 14C TRANSLOCATION IN BEAN (PHASEOLUS VULGARIS L.) AND COTTON (GOSSYPIUM HIRSUTUM L.)

Callose accumulated in the tissues of boron deficient bean and cotton plants, the extent and distribution of which depended on the species. Sieve plates in the phloem of boron deficient bean were characterized by heavy plugs of callose, while the sieve plates of boron deficient cotton were essentially unaffected. Translocation of ¹⁴C was, however, drastically reduced in both plants. It is suggested that callose deposition in boron deficient plants is a secondary effect of cellular damage.     

Experimentell erzeugte Bastarde zwischenDryopteris Filix-mas (L.) Schott undD. paleacea (Sw.) C. Chr.

Ohne ZusammenfassungMit 14 Textabbildungen.     

1072. Breynia vitis-idaea (Burm.f.) C.E.C.Fisch: Phyllanthaceae

Breynia vitis-idaea (Burm.f.) C.E.C.Fisch. is illustrated and its remarkable mutualism with a seed-parasitic moth pollinator is described. The species is cultivated in the glasshouse of Koishikawa Botanical Garden together with its specific moth pollinator, which helps the plant to produce showy red fruits throughout the year.     

STRUCTURE AND DEVELOPMENT OF THE SECRETORY CELLS AND DUCT SYSTEM IN MACROCYSTIS PYRIFERA (L.) C. A. AGARDH1

Sporophytes of Macrocystis pyrifera (L.) C. A. Agardh of various stages of growth were studied by light microscopy to determine the initiation and ontogeny of secretory cells and the accompanying duct system. Secretory cells are initiated by asymmetric, periclinal divisions of meristoderm cells; subsequent mitoses increase the number of secretory cells associated with each duct. Duct formation occurs by schizogeny of anticlinal cell walls adjacent to the site of secretory cell initiation. Differences in distribution and structure of the duct system occur in various parts of the sporophyte. The duct system does not have openings directly to the sporophyte surface. Histochemical techniques showed that the duct contents are mostly sulfated polysaccharides with perhaps some lipid.     

Carlina×bakariensis E.Mayer,hybr. nov. (=C. fiumensis Simk.×C. corymbosa L.)

Zusammenfassung Die chorologischen und morphologisch-taxonomischen Verhältnisse vonCarlina frigida Boiss. etHeldr.,C. fiumensis Simk.,C. graeca Heldr. etSart, undC. corymbosa L. im adriatischen Küstengebiet von Jugoslawien werden näher besprochen.Aus dem Gebiet des Quarnero wird der erste sichere Bastard innerhalb der GattungCarlina L.,C.×bakariensis (=C. fiumensis Sime.×C. corymbosa L.), beschrieben.     

Inhibition Of Thioredoxin Reductase (E.C. 1.6.4.5.) By Antitumor Quinones

Thioredoxin reductase (TR) is a widely distributed flavoenzyme that provides reduced thioredoxin, a dithiol hydrogen donor for protein disulfide reduction and for the reduction of ribonucleotides to deoxy-ribonucleotides, the first unique step of DNA synthesis. Antitumor quinones were found to exhibit time-and concentration-dependent inhibition of purified rdt liver TR that requires the presence of NADPH. Diaziquone initially shows competitive inhibition of the enzyme with 5,5′-dithiobis 2-nitrobenzoic acid as substrate with a K, of 7.5 SμM. which becomes non-competitive after I hour incubation with NADPH with a K, of 0.5 μM. Doxoruhicin shows non-competitive inhibition both initially and after 1 hr incubation with NADPH, with K_i values of 10μM and 0.5μM. respectively. Electron spin resonance spectroscopy showed the formation of semiquinone free radicals by TR incubated under anaerobic conditions with doxorubicin or diaziquone and NADPH. Redox cycling and formation of oxygen radicals does not play a major role in the inhibition of TR by antitumor quinones as shown by the minor effect on inhibition of removing O₂, and the lack of effect of superoxide dismutase and catalase. Diaziquone causes time- and concentration-dependent inhibition of TR activity in intact A204 human rhabdomyosarcoma cells that is associated with growth inhibition. The results suggest that inhihition of TR by antitumor quinones could contribute to their growth inhibitory properties     

ECOPHYSIOLOGICAL RESPONSES OF CERASTODERMA EDULE (L.) AND C. GLAUCUM(BRUGUIERE) TO DIFFERENT SALINITY REGIMES AND EXPOSURE TO AIR

The estuarine bivalve Cerastoderma edule and the lagoonal C.glaucum were exposed in the laboratory to different salinityregimes and the effects in the osmotic concentration of themantle cavity liquid, extrapallial fluid and haemolymph determined.The behavioural responses of the two cockles to changing salinityand exposure to air were investigated by monitoring valve movements. Both C. edule and C. glaucum are euryhaline osmo-conformerswhen exposed to different environmental salinities, but differencesare seen in their behavioural responses to sudden exposure tolow salinity and cyclic changes in salinity. C. glaucum postponedthe effect of sudden exposure to low salinity by complete valveclosure whilst C. edule partially closed its valves and intermittentlygaped during the same period. During exposure to a sinusoidalfluctuating salinity regime, C. edule responded first to thefalling salinity by retracting siphons and partially closingvalves. In contrast, C. glaucum responded more slowly to fallingsalinity than did C. edule. C. glaucum closed valves faster,accompanied by erratic adductions. During an acclimation period in a continuous automatic tidalsystem, C. edule and C. glaucum were entrained to the tidalrhythm of immersion and exposure to air and demonstrated differentresponses of valve gaping and adductions. This rhythm was lostupon continuous submergence indicating the rhythm is exogenouslyinduced. The two cockles gaped during exposure to air at lowtide, suggesting that both can respire in air, contrary to previousreports. The different physiological and behavioural responses of C.edule and C. glaucum to changing salinity and exposure to airwere found to be a reflection of their respective environments.C. edule is adapted to daily changes and stresses in its estuarinehabitat whilst C. glaucum is subjected to seasonal changes. (Received 19 September 1985;