摘要:

The presence of Euphorbia hyberna L. subsp. insularis (Boiss.) Briq. in the Ligurian Apennines. — The author studies the geographical distribution and the ecology ofEuphorbia hybernaL. subsp.insularis(Boiss.) Briq. in the Ligurian Apennines, where the plant occurs in several stations which are localized in two distinct areas: in the group of Mt. Dente (province of Genoa) and near the Capanne di Marcarolo (province of Alessandria).Euphorbia insularisis recorded only in Liguria, the Apuane Alps (Tuscany), Corsica and Sardinia. The climatic, edaphic, topographic and biotic characteristics of the stations in which the plant is found in Liguria are pointed out. It grows in different environmental conditions, but occurs only in localities with northerly or north easterly exposure, at altitudes between 700 and 950 m; it attains the best development in open places, like grassland and glades, where it grows profusely. On the whole,Euphorbia insularisrequires a climate characterized by a strong oceanicity, i.e. by moderate temperatures, a high amount of rainfall, and a notable atmospheric humidity throughout the year. However, the plant shows no particular edaphic requirements, and its occurrence on the serpentine soils is only due to the low competition in the plant-communities of these stations. The author emphasizes the remarkable phytogeographic interest ofEuphorbia insularis, which probably represents a tertiary atlantic relict and has survived in the Ligurian Apennines owing to peculiar geo-climatic conditions.

ISSN:0017-0070    

DOI:10.1080/11263507209426544

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A study of Sternbergia lutea Ker-Gawl lipidsoluble pigments during some phases of its biological cycle. — In the present paper we have examined the pigments ofSternbergia luteaand their variations during some particular phases of its biological cycle in order to obtain useful information on their probable function in the plant. Therefore, we have analyzed the pigments of the leaves, floral scape, tepals and anthers. The results obtained show thatSternbergia luteais characterized by the same pigment composition as that of the other higher plants. In addition to this, three further carotenoids have been observed (mainly in the tepals and anthers). Chromatographic and spectrophotometric properties of these new pigments indicate their relationship with carotene isomers that have already been examined. During the phases of vegetative cycle ofSternbergia luteachlorophylls and carotenoids increase concomitantly with the growth of the plant. Carotenes reach a significant maximum value only in anthers. In the course of the necrosis (that obviously occurs in different stages for the various organs) is observed a higher decrease of chlorophylls (in the green tissues) and of the carotenes (in the anthers) while lutein and violaxanthin increase greatly (in the tepals).

ISSN:0017-0070    

DOI:10.1080/11263507209426545

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A comparison has been made between the Quinacrine fluorescence bands and the bands obtained with a denaturating-reannealing-Giemsa technique inVicia faba. The results show that some of the bands, particularly on the M and, proximally, on the S chromosomes are visible with both techniques. A complex pattern of bands on the S chromosomes is revealed with the Giemsa technique. Both the similarities and the differences between the banding patterns obtained with the two methods inVicia fabamay indicate various degrees of DNA repetitiousness and other physico-chemical properties in the chromosome segments involved.

ISSN:0017-0070    

DOI:10.1080/11263507209426546

出版商:Taylor & Francis Group    

年代:1972

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:10.1080/11263507209426543

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor