摘要:

Effect of lycorine on the growth and pigment formation in some marine algae. In this investigation the effect of lycorine on the growth and pigment synobasis in some red and green algae has been dettermined. It has been observed that lycorine inhibits mainly the growth of algae and, to some extent, their pigment content. Moreover, the different permeability of the apical segment to the alkaloid determines various inhibitory effects. Lycorine 2 × 10−5M prevents the growth of red algae at about the same rate as in green algae. It is particularly interesting to observe that the concentration 10−7M does not influence the growth ofPterocladiawhile inhibiting its pigment formation. Phycoerythrin has shown a sensitivity to lycorine higher than those of chlorophylls and carotenoids. It is established that carotenoid protect the cells of algae and higher plants, from lethal photoxidation. So, the inhibition of carotenoids formation is suggested as the primary effect of lycorine which is responsible for the highest reduction of phycoerythrin and also of the growth.

ISSN:0017-0070    

DOI:10.1080/11263507409426343

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Floristic notes and geographical distribution of some rare Rhodophyta (Kallymeniaceae and Sebdeniaceae) of the western Mediterranean. Callophyllis laciniata, Kallymenia requieniiandKallymenia lacerata (Kallymeniaceae)andSebdenia rodrigueziana (Sebdeniaceae)are recorded for the first time in the bay of Naples. For each species systematic and distribution data are also given.

ISSN:0017-0070    

DOI:10.1080/11263507409426344

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Cytotaxonomic notes on the genus Biarum Schott (Araceae) in Italy. Morphological and caryological observations on sicilian and italian specimens ofBiarum tenuifolium(L.) Schott could not prove its taxonomic separability from B.cupanianumPaglia. In our opinion the latter is to be considered as a synonym of the former. The chromosome number ofB. tenuifoliumis very variable (2n= 16, 20, 26); the chromosomes show eu- and heterochromatic regions. A sardinian plant usually assigned toBiarum boveiBlume needs further studies in order to verify its taxonomic identity.

ISSN:0017-0070    

DOI:10.1080/11263507409426345

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

No effect of weak magnetic fields on seedlings growth of Triticum. No effect of multiple intensities of -4, -1, 0, 1, 4, 6 times the geomagnetic field on the growth ofTriticumseedlings, measured as length, fresh and dry weight, has been found. The experiments were carried out in darkness at 20°C, according to an experimental design including 2196 seedlings placed within the 6 fields with 2 orientations of the embryos (North- and South-wards) and two replicates at the same time. All treatments have been repeated 6 times in 6 different locations. In spite of the statistical significance of the weak magnetic fields «effects» on plants, found from previous researchers, it is very probable that these «effects» are only casual; the results are contradictory, particularly those on the directional «effects»; often the total number of plants and of replicates (sometimes only one) is very low and the environmental conditions are not controlled. Care must be taken in interpreting the results of the probability tests: in analyzing weak effects on these materials the tests have a limited strength and this may produce pseudoeffects, i.e. «probabilistic elaboration effects». The tests easily lose their meaning when they are notstrictlyused according to the theorical conditions, which may not be easily realized. At high intensities no definite responses curves to the intensity and to the direction of the magnetic vector are available. Teratological, pathological, inhibiting as promoting effects on plants growth and development have been recorded. The strong magnetic fields action shows some analogies with that of the ionizing radiations, for their aspecific, casual and disorganizing effects on the physiological processes.

ISSN:0017-0070    

DOI:10.1080/11263507409426346

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Chamaecytisus hirsutus and C. supinus: a preliminary report. – Chamaecytisus hirsutus(L.) Link andC. supinus(L.) Link have been described as twostrictly related species, which differ mainly in the form of inflorescence:C. hirsutushas lateral flowers,C. supinushas terminal flowers. Besides, most Floras provide a set of additional differential characters that should permit to di-C. hirsutusandC. supinus.

ISSN:0017-0070    

DOI:10.1080/11263507409426347

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Karyotype analysis of Iris gramineaL. The karyotype ofI. gramineaL. shows 2n= 34 chromosomes of the following morphology (LEVAN, FREDGA, SANDBERG, 1964):a) 2 metacentric «m» pairs (1, 2) with a secondary constriction on each arm;b) 1 metacentric «m» pair (3) with one secondary constriction on the long arm;c) 2 pairs (4, 5) one «M», and the other «m», both pairs have a terminal secondary constriction;d) 2 submetacentric «sm» pairs (6, 7) with a big satellite on the short arm;e) 1 submetacentric «sm» pair (8) without secondary constrictions;f) 2 metacentric «m» pairs (9–10) with a terminal secondary constriction on the long arm;g) 7 submetacentric «sm» pairs (11, 12, 13, 14, 15, 16, 17), which slightly differ in size, without secondary constrictions. The lenght of the chromosomes varies between 2,5 and 0,9μm.

ISSN:0017-0070    

DOI:10.1080/11263507409426348

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Embryological, systematic and ecological observations on Allium parciflorum Viv. The morphological observations and the comparison with some allied species have shown a good taxonomic isolation ofAllium parciflorum: this has suggested to ascribe it to a new section.

ISSN:0017-0070    

DOI:10.1080/11263507409426349

出版商:Taylor & Francis Group    

年代:1974

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:10.1080/11263507409426342

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor