摘要:

rDNA restriction pattern in two different biotypes ofOrnithogalum montanum(with 11 Q-bands and 2 B chromosomes and with neither Q-bands nor B-chromosomes) was examined by Southern blot hybridization of Eco RI, Bam HI and Sac I) digests of nuclear DNA using32P rRNAs.

ISSN:0017-0070    

DOI:10.1080/11263508909430252

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Acrospongium ralfsioidesSchiffner andRalfsia expansa(J. Agardh) J. Agardh are recorded from the Alboran Sea.A. ralfsioidesis a rare species known only from the original description whileR. expansa, a pantropical species, is recorded for the first time in the Mediterranean. The vegetative habit and the reproductive structures of these two crustose brown algae are described together with some data on their ecology.

ISSN:0017-0070    

DOI:10.1080/11263508909430253

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The life cycle ofScrippsiella precariaMontresor & Zingone was studied using a clonal culture. At 25[ddot]C and 100 μE/m2/s a maximum growth rate (kmax) of 0.53 div./d was calculated. Vegetative reproduction takes place through ecdysis. The naked protoplast emerges from a non motile cell characterized by a thin emphiesma. In some cases, cell division occurs after the loss of the parental amphiesma. In other cases, the division process is nearly complete when the two daughter cells are freed. In standard culture conditions, resting cyst formation was observed toward the end of the log growth phase. Cysts developed within a non-motile form, similar to the one preceding ecdysis. Attempts to observe conjugation and zygote formation were unsuccessful. Smaller, less pigmented cells were observed attached in the sulcal region. In all experiments conducted so far these cells, which we supposed to be gametes in analogy with other dinoflagellates, were not seen to fuse. The characteristics of the life cycle ofS. precariaare compared with those of other dinoflagellates.

ISSN:0017-0070    

DOI:10.1080/11263508909430254

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Optical and SEM observation on the thallus ofLunularia cruciatashow the presence of a hyaline parenchyma consisting of polyedric, slightly elongated cells with secondary wall thickenings mostly parallel. After removal of cytoplasmic content by mean of Triton-X-100, SEM observations show that the walls of the reticulate cells constituting the hyaline parenchyma have, between wall thickenings, large primary pit fields with numerous plasmodesmata derived pores on the unthickened areas of the walls. By contrast, the parenchymatous cells constituting the nerve have plasmodesmata derived pores grouped in small sparse fields, especially on the transverse of oblique walls. The authors suggest that the reticulate cells play a role in water holding capacity and lateral distribution, by symplastic and apoplastic conduction, of solutions carried by the midrib. A possible uniform pattern for water transport and distribution in all Marchantiales showing a similar histological organization of thallus is also hypothesized.

ISSN:0017-0070    

DOI:10.1080/11263508909430255

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263508909430256

出版商:Taylor & Francis Group    

年代:1989

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:10.1080/11263508909430251

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor