摘要:

New cytological data on the genus«Muscari» and «Leópoldia». —Leopoldia holzmanniHeldr. andMuscari szovitzianumBaker have been cytologically studied. The species are diploids: 2n= 18. The caryotype structures are: 1.Leopoldia holzmanni:z= 2n= 18:4L+6M+8S (as the other species previously investigated). 2.Muscari szovitzianum:z= 2n= 18:2Ls+2L+8M+6S. InLeopoldia holzmannias in other species of the genus, we have noted heterozygosity in one chromosome pair. The taxonomical disjunction between genusLeopoldiaandMuscariis further confirmed.

ISSN:0017-0070    

DOI:10.1080/11263506909426492

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Isolation of Cytokinins from«Rhizobium leguminosarum»Frank.— Three substances with cytokinin activity have been isolated from liquid cultures ofRh. leguminosarumby fractionation on Dowex 50W X4 H+column, butanol extraction, silver precipitation, chloroform extraction and finally by paper chromatography. The Rf-values and the U.V. absorption maxima of one of these substances were similar to those of isopentenyl adenine, a potent cytokinin synthetized by several bacteria responsible, asRhizobium, for profound morphological alterations of the tissues of higher plants. The other two substances are not comparable to any of the as yet known natural cytokinins. It is suggested that these substances, produced byRhizobium, are responsible for tissue proliferation during nodule formation.

ISSN:0017-0070    

DOI:10.1080/11263506909426493

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The vegetation of«fontanili»in Lomellina.— Some observations on « fontanili » vegetation are reported. It is known that in « fontanili » it is possible to distinguish a « testa », artificially excavated, where Springs gush, and a canal called « asta » or « cavo di fontanile » or « fontanile » as well. Observations repeated after a few years have allowed us to ascertain that in the abandoned « teste », where springs do not gush very actively, vegetation changes remarkably and from an aspect dominated byApium nodiflorum, Veronica anagallis-aquatica, Myosotis palustris, Nasturtium officinaleand a few other species passes first to populations ofLemna minor, in surface, and ofCeratophyllum demersumand after some years more to an aspect dominated by species of theGlicerieto-SparganionasGlyceria fluitansandSparganium ramosumand of thePolygono-BidentetumasPolygonum hydropiperandBidens cernua.Along the « aste » two aspects may be observed. One is that of the floating vegetation expecially represented byCallitriche palustrisand byHelodea canadensis, Potamogeton crispa, P. densa, Myriophyllum spicatumand a few other species. This type of vegetation is to be ascribed toPotameto-VallisnerielumBr.-Bl. 1931. The other one is again an aspect similar to that of the active « teste ». It is quite possible to remark this type of vegetation with phytosociological method and a summary list of twenty remarks is given:Apium(orHelosciadum) nodiflorum, Class of presence V;Callitriche palustris, V;Nasturtium officinale, V;Veronica anagallis-aquatica, V;Myosotis palustris, V;Phalaris arundinacea, V; and, less represented, (Class I),Lemna minor, Glyceria fluitansandMentha aquatica.This type of vegetation is to ascribe to theHelosciadetumBr.-Bl. 1931.

ISSN:0017-0070    

DOI:10.1080/11263506909426494

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

New or rare microfungi of Italy, isolated from coastal forest soil of Tuscany.«Humicola parvispora»n. sp. and « Gonytrichum macrocladum»(Sacc.) Hugh. v.«terricola».n. var.— Two molds, aHumicolaand aGonytrichumspecies, isolated from coastal soils of Tuscany, are described. The history of the genusHumicolais shortly reviewed; regarding its generic features, some characters described for more recent species (possible absence of fialides, aleuriospore catenulation, chlamydospore formation) are considered and connexions with similar genera are discussed together with the possibility of utilising physiological and/or ecological characters. The present strains is mainly characterized by the presence on hyaline hyphae of small, brown or dark-brown, smooth, globose or subglobose (μ 4,2-6-8,4), pyriform or broadly clavate (μ 3,6-4,8-6,6 × 5,4-8,8-12) aleuriospores, single or in small aggregations, together with the presence of chlamydospores or toruloid/chlamydosporioid bodies. A new species is proposed:H. parvispora, About the strain ofGonytrichum, its fundamental features, as well as its morpho-metrical characters, allow to consider it asG. macrocladum(Sacc.) Hughes. However, some other characters have been evidenced which do not agree with those already described for this species. Simple conidiophores ofBisporomyces-type are present; conidia production at apex of conidiophores as well as of lateral phialides occurs in pairs, one conidium is but slightly successive to the other, like inBisporomyces lignicolaMangenot. There was no possibility to evidence a double opening at apex of phialides, as described by Swart, but only an imperceptible joint of young conidium with phialide, until it is out of collarette. Phialides of second order on proliferating first order phialides have been observed, even rarely and under particular conditions. Sometimes the main axis shows a sort of ‘bifurcation’ that is here interpreted as something like a direct branching. All these features, together with the occurrence of the fungus in soil, seem to indicate the presence of a subspecific taxon ofGonytrichum macrocladum(Sacc.) Hughes. It is therefore proposed to establish the new varietyterricola.

ISSN:0017-0070    

DOI:10.1080/11263506909426495

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

New data on the ecology and distribution of « Althenia filiformis » Petit in Puglia (Italy). — Althenia filiformisPetit subsp.filiformis(Potamogetonaceae), has been discovered, during some researches along the Southern Italian shores, in some salt pools of the Apulian coast, south of Manfredonia. The pools in whichAltheniahas been discovered are the remaining parts of pools wider in the past and now partly reclaimed. At the same time it has been ascertained thatAltheniais not detectable in the Salpi lake, station where it was first found (RABENHORST1849–50). This fact is probably due to the partial reclamation of the lake and to its transformation into salters (Saline Margherita di Savoia).

ISSN:0017-0070    

DOI:10.1080/11263506909426496

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

On the behaviour of immature embryos and endosperms of«Triticum » seeds.— The author has analysed, by embryo-transplantation tecnique: 1) the behaviour of after-ripe embryos transplanted on immature endosperms ofTriticum, and 2) the behaviour of immature embryos transplanted on after-ripe endosperms. The results confirm the « inhibition state » of immature embryos, as revealed by germination values but show that their growth is affected positively by after-ripe endosperm. The immature endosperm induces an inhibitory effect on germination and growth of after-ripe embryos. This fact is explained on the basis of some « food deficiency » and the possible presence of inhibitors in immature endosperm.

ISSN:0017-0070    

DOI:10.1080/11263506909426497

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The essential oils of « Satureja variegata»Host(«S. montana » auct. plur., non L.) growing on the Karst near Trieste.— The present paper deals with the analysis of the essential oils ofSatureja variegataHost, a species analogous toSatureja montanaL., growing on the Karst (near Trieste, Italy). The components were found by coupling gas-chromatography and infrared spectoscopic analysis of the essential oil extracted by steam distillation. The samples were gathered from two zones of different vegetation in order to determine the possible variations due to the environmental conditions. Furthermore the seasonal variations of the essential oil is typical of the species, whilst the quantitative composition appears to have only small variations. The yield as percentage of the essential oil extracted (referred to the dried weight of the sample) is highly affected by the environmental conditions.

ISSN:0017-0070    

DOI:10.1080/11263506909426498

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue

ISSN:0017-0070    

DOI:10.1080/11263506909426491

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor