Assunzione Di Metaboliti Da Parte Di « Cuscuta Epithymum » Parassita Di « Trifolium Repens »

Abstract

Uptake of metabolites by CUSCUTA. — The distribution of the radioactivity in the filaments of Cuscuta epithymum attached to the host (Trifolium repens) growing in an atmosphere of C¹⁴O₂ indicates that the dodder uptakes from the host solely, or mainly, sucrose. The other radioactive compounds present in the extracts of Cuscuta appear to be derived from the sucrose rather than uptaken from the host.     

Effetti Morfologici,Anatomici Ed Ultrastrutturali Indotti Dai Ritardanti Di Crescita Su Plantule Di Pisum Sativum L. Var. « Gloria Di Quimper » Cultivate in Soluzione Nutritizia

Abstract

The effect of the growth retardants on the structure of Pea seedlings coltured in nutritive solution. – The addition of CCC (2-Chloro-ethyltrimethyl ammonium chloride) and AMO 1618 (4-Hydroxyl-5-isopropyl-2 methyl-phenyl-trimethylammonium chloride. 1-piperidine carboxylate) to Pea seedlings (Pisum sativum L. var. Gloria di Quimper) promotes the usual modifications induced by growth retardants on higher plants. CCC appears less effective than AMO 1618; CCC inhibits growth only at 10²-M. concentration, on the contrary 5×10-⁵M. AMO 1618 inhibits strongly the growth of the seedlings both in the light and in darkness. CCC and AMO 1618 operate similarly as far as the inhibition of expansion growth, the increase of the stem diameter, and the decrease of the apical dominance are concerned. 10-²M. CCC stimulates both the growth of roots and the secondary roots formation, on the contrary 2,5×10-⁴M. AMO 1618 inhibits strongly the growth of the roots. AMO 1618 affects more strongly than CCC the expantion growth of the leaves. Leaves of the AMO 1618 treated plants are greener than the control plants. Plants treated with CCC and AMO 1618 are smaller because these chemicals inhibit the expantion growth of the cells. The increase of the stem diameter induced by CCC and AMO 1618 is due to the stimulation of the mitotic activity of the cambium. AMO and CCC induce a decrease of the size of the vessels and the sieve tubes. In the sieve tubes of the treated plants and slime plugs appear near to the sieve plates many slime bodies. AMO and CCC did not affect the mitotic activity of the apical meristems; in fact the plants grown in the presence of the growth retardants, show a normal primary body. AMO and CCC delay the lignification process. Chloroplasts of this Pisum sativum variety show prolamellary bodies associated to a good lamellar system. Starch granules are always present. Starch was never found in the chloroplasts of the treated plants. The general picture of the effects induced by growth retardants in Pea seedlings show so many modifications that it is very difficult to believe, like some Authors suggest, that all the effects produced by growth retardants are due to the inhibition of gibberellin biosynthesis.     

Osservazioni Sull'attività Cambiale Di Nerium Oleander L.

Abstract

Observation on the cambial activity in «Nerium oleander» L. — The cambial activity of «Nerium oleander» has been observed in three localities in Southern Italy: Bari and Lucera, where the oleander is cultivated, and Policoro, in the bed of the river Sinni, where the oleander is spontaneuos. The wood is of the diffuse-porous type. Growth rings corresponding to distinct periods of growth are not distinguishable, as there are no easily distinguishable types of wood (early, intermediate, and late wood). Only occasionally the uniform wood is interrupted by narrow circular bands of a few layers of radially compressed cells. Differences in the behaviour of the cambium have been observed in the three localities. At Policoro there was a long period of activity from the middle of March until November without interruptions. At Bari the cambium was active from the middle of March until the first days of April; after a pause it was active again from the second half of May until die middle of July and again during the second half of September-October and the first ten days of October. In 1957 a slight activity was noticed also during about twenty days in December. At Lucera the active period as compared with Policoro was still shorter than at Bari; in the spring there was a delay in the resumption of activity, while the summer rest period lasted until the middle of October. The cambium was then active again until the first days of November. Some of the differences in the behaviour of the cambium in the three localities could perhaps be explained by climatic or pedologic factors, such as the rich water table in the case of the plant growing in the Sinni bed. In conclusion «N. oleander» seems to be a species adapted to a sub-tropical climate, without distinct growth rings.     

Rapporti Embrione-Endosperma in Triticum Durum: Velocità Di Utilizzazione,Da Parte Dell'Embrione,Di 3H-Tdr. Proveniente Dall'Endosperma

Abstract

Embryo-endosperm relationship in «Triticum durum» seeds: embryo utilization speed of ³H-Tdr from the endosperm. — The transferring speed of DNA labeled precursor (³H-Tdr) from endosperm to embryo, in Triticum, has been detected by embryo transplantation technique. The results show that the first hour (after transplant) some cells (3%) in root meristem incorporated ³H-Tdr. Labeled cells frequency is increasing between the first and the third hour of experiment, up to 25%; thereafter the percentage keeps constant. The histological location of cells and/or an insufficient availability of ³H-Tdr (from the endosperm) might explain the low labeling index detected in the above experiment.     

Fissazione Dell'Anidride Carbonica Da Parte Di « Cuscuta Epithymum »

Abstract

CO ₂ fixation by CUSCUTA EPITHYMUM. — Seedlings of Cuscuta epithymum or filaments detached from the host (Trifolium repens) fix carbon dioxide by mechanism(s) which are, though to a different extent, stimulated by light. Chromatographic analysis of plant extracts that have assimilated C¹⁴O₂ indicates that, in all cases, the radioactivity is detectable in the areas corresponding to the organic acids and the acidic amino acids. No labelling was associated in appreciable amounts with 3-pho-sphoglycerate and the mono- and diphosphate esters of hexoses and pentoses. Such results are substantiated by the finding that cell-free extracts of seedlings and filaments fix carbon dioxide by carboxylating phosphoenolpyruvic acid. It is concluded that, under the experimental conditions, malic enzyme, pyruvate carboxylase and ribulose-1,5-diphosphate carboxylase have little, if any, significance in the fixation of carbon dioxide by the tested species of Cuscuta.     

Nuovi Dati Sulla Distribuzione Di Isoétes Malinvernianum in Lomellina

Abstract

New data on the distribution of « Isoëtes malinvernianum » in Lomellina. — The Author relates the discovery of many new stations of Isoëtes malinvernianum in Lomellina (Province of Pavia). Many observations carried out in these new localities and in the most part of the already recorded localities near Novara and Vercelli have allowed him to modify some convincements on the habitat of this well known endemism. So he reports that Isoëtes malinvernianum vegetates not only in the waters of « fontanile » but also in waters of the most different sources, that this species is not solitary but accompanied by many species as Callitriche palustris, Fontinalis antipyretica, Sagittaria sagittifolia, Vallisneria spiralis, Potamogeton crispa and few other species more. Isoëtes malinvernianum, besides, is not damaged by dredge works in the canals and is present not only in morainic soils and in the diluvial soils transformated in ferreto but also in the terraced flood named with old terms as « Terrazziano » or « Diluvium recente » and in the diluvial soils of the « Alluvium ». Now at least it is not possible to ascribe plant communities of which Isoëtes malinvernianum makes part to a well defined association.     

Lo Sviluppo Del Sistema Conduttore Di “Ginkgo Biloba” L.

Bupleurum gracile (M. Bieb.) DC. var. rollii Montel. ( ≡ Bupleurum rollii [Montel.] Moraldo) is lectotypified on a herbarium specimen kept in RO, revising the previous typification by S. Snogerup and B. Snogerup. An isolectotypes and 14 syntypes are also selected. Infraspecific variability and comparison with related Eastern species B. asperuloides Heldr. B. uechtritzianum S. Stoyanov and B. marschallianum C. A. Mey plus B. gracile D'Urv. are studied using morphometric and anatomical data. Notes on the ecology and distribution of the Italian endemic taxon are also provided.     

Lo Sviluppo Del Sistema Conduttore Nelle Plantule Di “Opuntia Vulgaris„ Mill.

Aquatic mosses and sediments were monitored along Topolnitsa River Basin (Bulgaria), copper-producing and mining region. Six mosses were applied as biomonitors: Bryum turbinatum, Fontinalis antipyretica, Leptodictyum riparium, Platyhypnidium riparioides, Rhizomnium punctatum and Sciuro-hypnum plumosum. Background levels were determined for both plants and fine fraction of sediments collected from an unpolluted site. Contamination factors (CFs) and metal pollution index at each site were presented. The highest sediment enrichment with toxic elements was found in Zlatishka River. Strong increase above background levels showed all 13 heavy metals and toxic elements in biomonitors from stations at Zlatishka and Pirdopska rivers. The two moss species adopted as biomonitors for the first time – Bryum turbinatum and Rhizomnium punctatum – showed high CFs for several heavy metals and contributed to chemical pollution pattern assessment. The parallel use of mosses and sediments in the monitoring study, as well as the applied statistical tools, led to the conclusion that mosses as higher plants revealed pollution patterns not detected by sediments. Results also showed that in a seriously contaminated aquatic environment, which requires rapid assessment, different moss species can be applied for water-monitoring purposes to present preliminary picture of pollution patterns and to direct further studies.     

新型α-芋螺毒素Di1.1的克隆、合成及功能研究

目的：从中国南海长距芋螺中克隆出新的芋螺毒素序列并用固相方法合成该毒素,测定其折叠后的二硫键配对方式并初步研究其药理学特性。方法：根据芋螺毒素A超家族保守的信号肽序列设计引物,通过3＇-RACE扩增,从芋螺毒腺管中克隆出新的毒素基因;采用Fmoc-固相法合成线性多肽,通过空气氧化折叠获得含二硫键的折叠产物,用两步氧化折叠法测定多肽的二硫键连接方式;用双电极电压钳技术初步研究其药理学特性。结果：发现-种新的α-芋螺毒素Dil．1的cDNA序列,其成熟肽序列为CcVIESCHSNHIDECES;该肽二硫键连接方式以C1-C4、C2-C3为主,以C1-C3、C2-C4连接为辅,对烟碱型乙酰胆碱受体各亚型活性较弱。结论：Dil．1是-种新的α4／7型芋螺毒素,其折叠方式以C1-C4、C2-C3连接为主。     

Studio Del Ritmo Vegetativo Di Olea Europaea L. in Messina Negli Anni 1952–54

Summary

The vegetative growth of the olive tree in Messina is described. The growth period begins at the end of March and prosecutes without interruption as late as November. The secondary wood tissue producted during summer time (from Yuly to August) is abnormal being of a parenchimatoide type. During winter there is a well defined rest period.

The cambium produces secondary wood and bark with an alternate rythm, so that in spring the wood production prevails on the liber and in autumn the opposite condition is realized.

Each phase of production of secondary conducting tissues (wood as well as bark) is followed by a phase of starch storing.

In the stem several false wood rings are produced during one year, while in the young branches each wood ring corresponds to one year.

The longitudinal growth and cork formation on the branches of the year are particularly pronounced during spring (March-May).

Cambium cells swell in a characteristic way before they start dividing and collapse during the resting periods, thickening evidently their walls, so that in winter it is difficult to distinguish a cambial cell from a parenchimatic one.

The behaviour of the vegetative growth of the olive tree in Messina is discussed on the base of the climatic characters of the region.     

Di Alcuni Caratteri Differenziali Nelle Plantule di “ Cuscuta Epithymum „ Mürr. e di “ Cuscuta Pentagona „ Eng.

Endophytes are micro-organisms that colonize the internal tissues of plants without inducing signs of negative effects and that can provide benefits to plant health and yield. In the present work, the culturable bacterial endophyte community, colonizing vegetative organs of grapevine, was isolated from surface-sterilized plant tissues and characterized by molecular methods. From roots, shoots and leaves of Vitis vinifera “Glera”, located in six different vineyards throughout the Conegliano-Valdobbiadene DOCG area (Veneto, Italy), 381 culturable strains were successfully isolated; amplified ribosomal DNA restriction analysis and nucleotide sequencing showed that approximately 30% of the endophyte community belonged to the genus Bacillus, which was the most represented; other genera such as Staphylococcus, Microbacterium, Paenibacillus, Curtobacterium, Stenotrophomonas, Variovorax, Micrococcus and Agrococcus were identified. Endophyte community composition within each vine was different in respect to other endophyte populations living in grapevine plants coming from different vineyards; moreover, the bacterial composition changed depending on the season of sampling. The above data highlight the great diversity of culturable bacterial species inhabiting Glera grapevines and open the way for a characterization and selection of strains that could potentially be used to improve the vineyard management for plant growth and yield, plant responses to stresses, biocontrol and biofertilization.     

An Efficient Route to Novel 4,5‐Di‐ and 2,4,5‐Tri Substituted Imidazoles from Imidazo[1,5‐a]‐1,3,5‐triazine (5,8‐Diaza‐7,9‐dideazapurine) Derivatives

Two new types of imidazole derivatives: N‐(2‐R¹‐5‐R²‐1H‐imidazol‐4‐yl) thioureas 7a–g and N‐(2‐R¹‐5‐R²‐1H‐imidazol‐4‐yl) formamides 8b,c,g were obtained in high yields by the hydrolytic degradation of 6‐R¹‐8‐R²‐2‐thioxo‐2,3‐dihydroimidazo[1,5‐a]‐1,3,5‐triazin‐4(1H)‐ones 5a–g and 6‐R¹‐8‐R²‐imidazo[1,5‐a]‐1,3,5‐triazin‐4(3H)‐ones 6b,c,d, respectively. The tautomeric preferences of the new imidazoles were determined.     

Molecular markers reveal a strong genetic differentiation between two European relic tree species: Zelkova abelicea (Lam.) Boissier and Z. sicula Di Pasquale, Garfì & Quézel (Ulmaceae)

Chloroplast (trnL) and ribosomal (ITS2)sequences and chloroplast DNA (PCR-RFLP andSSR) markers were analysed in two relicUlmaceae tree species: Zelkova abelicea,from Crete, and Z. sicula, from Sicily.The analysis of the plastidial trnLintron and of ITS2 ribosomal sequences revealedtheir divergence from the related speciesZ. carpinifolia, widespread in the Caucasianregion; one base substitution in the trnLintron was detected between the twoMediterranean species, thus suggesting theirrecent separation. Molecular markers(plastidial PCR-RFLP and SSR) showed an evidentgenetic differentiation between Z. siculaand Z. abelicea, the two species beingcharacterised by different haplotypes. Nowithin population variation was detected usingdifferent chloroplast markers inZ. abelicea and Z. sicula. Paleobotanicaldata proved that the genus Zelkova wasabundant and widespread in central Italy untilit became extinct in the continental part ofEurope during last glaciation events andsurvived only in two Mediterranean islands. Thesegregation of the two Mediterranean relicspecies might have occurred as a consequence ofthe strong reduction of their distribution andthe following geographic isolation. Geneticdrift may have determined the drastic reductionof within stand diversity as observed in othersmall, peripheral and geographically isolatedplant populations. The priorities forconservation programs are discussed in thelight of the different genetic resourcesrepresented by the two taxa.