摘要:

By different chemical, spectral and chromatographic procedures seven carotenoids, two carotenes (α- and β-carotene) and five free xanthophylls (violaxanthin, lutein, antheraxanthin, zeaxanthin and neoxanthin) have been isolated and identified in green apple leaves. In autumn senescing leaves, besides the above seven carotenoids, the occurrence of at least seven xanthophyll esters has also been proved. Four esters, violaxanthin mono- and diester and lutein mono- and diester, (≥90% of total esters) and a minor component, neoxanthin triester, have been identified. Another minor component is most probably a monoester of antheraxanthin; the seventh, present in traces, has not been identified.

ISSN:0017-0070    

DOI:10.1080/11263508209428055

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Presence of Rhodymenia delicatula P.J.L. Dangeard in the Mediterranean. - The presence ofRhodymenia delicatulaP.J.L. Dangeard (Rhodophyta, Rhodymeniales) in the southern Thyrrhenian sea is reported. Both cystocarpic and tetrasporic individuals have been collected. Anatomical features of the reproductive structures, as well as the position of these on the thallus allowed the identification of this species formerly known for the Atlantic coasts of Morocco and British Isles.

ISSN:0017-0070    

DOI:10.1080/11263508209428056

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

It has been studied long term effects of copper upon physiological processes and growth ofChlorella saccharophila(Krüger) Migula andCyanidium caldariumGeitler, two algae which have the optimum of pH at 6,3 and 1,5 respectively. The algae differed markedly in their resistance to the copper. Infact, growth ofChlorella saccharophilashowed a lag time in presence of sublethal copper concentrations (0,25-1 mg/l). By contrast,Cyanidium caldariumwas about 4000 fold more tolerant to the metal. In both algae photosynthesis was more sensitive to applied copper than was respiration.

ISSN:0017-0070    

DOI:10.1080/11263508209428057

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A method for silybin, silydianin and silychristin (as well as taxifolin) visualization under long wave UV on silica gel TLC plates devoid of fluorescent indicator is described.

ISSN:0017-0070    

DOI:10.1080/11263508209428058

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Acetylene reduction by detached nodules ofAlnus cordata, A. glutinosaandColletia paradoxawas tested with respect to the effect of temperature on nitrogenase activity. Nodules were incubated at temperatures from 5°C to 45°C, exposed to C2H2generally for 1 hr, and sampled for C2H4. The maximum of activity occurred in all three species tested at about 25°C. The C2H2reduction rapidly declined at temperatures above the optimum and stopped at 40°C forA. glutinosaand 45°C forA. cordataandColletia paradoxa. Nodules of.A. cordatasubjected to 5°C recovered nitrogenase activity within 1 hr when the temperature was raised to 25°C, whereas loss of activity was irreversible at 45°C.A. cordatanodules tested in different seasons of the year showed similar activities in April and October with a slightly lower rate in August and a very much lower activity in January.

ISSN:0017-0070    

DOI:10.1080/11263508209428059

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Antrodia onychoides(Egel.)Ryv., new to Italy and very rare species in Europe. II. - The paper is concerned with the first Italian collection ofA. onychoides, a resupinate polypore. From the literature, this is the fourth European finding ofAntrodia onychoidesand follows the first collection, occurred in 1913 near Oslo, in Norway, the second in France and the third in Finland.

ISSN:0017-0070    

DOI:10.1080/11263508209428060

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The present paper examines some biological and ultrastructural aspects of fertilization and early development of the embryo inCytinus hypocistis, a parasitic plant belonging to theRafflesiaceae. The probable functions of a mucilaginous substance contained in the ovary and embedding the numerous pollen tubes coming from the style are discussed.

ISSN:0017-0070    

DOI:10.1080/11263508209428061

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Viability and germinability tests were carried out on the pollen ofCrocus sativusL., a sterile triploid commonly known as saffron. Pollen taken from dehiscent anthers was examined by means of vital staining and cytochemical techniques in order to detect its viability; germinationin vitrowas evaluated. From the results obtained it is evident that saffron pollen is viable at a high percentage (65%) but germinates at a very low percentage. Moreoverin vitrogermination is very slow, and is accompained by numerous morphological anomalies. The low germination of the pollen is due to the triploidy ofC. sativus.

ISSN:0017-0070    

DOI:10.1080/11263508209428062

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Ecological, plant geographical and morphological considerations on the genus Anthriscus Pers. - Analysis of the ecological, plant geographical and morphological characteristics of the genusAnthriscushas shown that his diffusion on broad geographical areas stays in connection with the transition of the single entities from the natural habitats to those semi-natural and synantropic. This passage is accompanied by a lowering of the inferior altitudinal limit of the distribution of the single species. In this genus has been observed a reduction series regarding the duration of the life cycle (from perennial herbs to biennal and annuals) and the size of the vegetative and reproductive apparatus.

ISSN:0017-0070    

DOI:10.1080/11263508209428063

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The composition of the stigmatic exudate of Citrus limon(L.)Burm. - Biochemical analyses of the stigmatic exudate ofCitrus limon(L.) Burm. have revealed the presence of lipids, polysaccharides, proteins, phenols, free aminoacids and alkaloids. The role of stigma secretion is discussed in relation to pollen activation and recognition and the pollen tube growth.

ISSN:0017-0070    

DOI:10.1080/11263508209428064

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor