摘要:

The new speciesPsathyrostachys stoloniformisnative to China is described. The karyotype was investigated by C‐, N‐, and Ag‐banding. The new species has 2n = 2x = 14, including 8 metacentric and 6 SAT‐chromosomes with minute satellites, distributed either on 3 or on 4 chromosome pairs. The C‐banding pattern comprises from one to six conspicuous and from zero to three very small bands per chromosome. Often two bands placed close together appear as one large band. The karyotype suggests thatP. stoloniformisis closely related toP. juncea.N‐banding produced very weak or no bands. Meiotic analyses of interspecific hybrids revealed a high chiasma frequency indicating thatP. stoloniformishas the same basic genome (N) asP. huashanica, and

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00535.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The micromorphology of the seeds of species ofOrnithogalumgenus found in North Africa is studied by SEM. Each species is characterized by a specific ornamentation which gives a high systematic value to this character. The ornamentation of the seed undergoes deep modifications during dessiccation. The supraspecific grouping based on this character do not correspond with the traditional classification of the genus. The phyletic value of this character is discussed.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00536.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The phylogeny of the Gerbera‐complex (Compositae, tribe Mutisieae, subtribe Mutisiinae) is discussed with the use of cladistics. 14 OTUs are accepted, viz. 1.Trichoclines. str., 2.Lulia, 3.Trichocline spathulata (“Amblysperma”), 4.Gerbera hieracioides, 5. Chaptalia, 6.Leibnitzia, 7.Uechtritzia, 8.Perdicium, 9.Gerberasect.Gerbera, 10.Gerberasect.Parva, 11.Gerberasect.Lasiopus, 12.Gerberasect.Piloselloides, 13.Gerberasect.Pseudoseris, and 14.Gerberasect.Isanthus.The work is mainly based on SEM‐studies. The paper discusses the phylogenetic and taxonomic implications of the presented consensus‐tree. It is proposed to rank theGerbera‐complexas a single,

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00537.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00538.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Taxonomy and nomenclature of sixNerviliaspecies occurring in the Flora Zambesiaca area are revised. Lectotypes or neotypes are selected for all relevant taxa from Africa. The new speciesN. gassneriis described and the new combinationN. kotschyivar.purpuratais made. One widespread African species previously mostly known under the namesN. humilisandN. reniformisis shown to be conspecific with the widespread Asian and Australien speciesN. crociformis.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00539.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00540.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The micropyle and the integuments of sugar beet(Beta vulgaris)ovules have been investigated by light and electron microscopy during differentiation and maturation of the ovule. The micropyle itself is formed by the inner integument which is surrounded by the outer integument at its base. The micropyle containts a fibrillar PAS+ substance and is often covered by a thin sheet or hymen. Both integuments are cuticle‐covered thin sheets, each 2‐few cell layers in thickness. In the outer integument an increase in starch accumulation occurs during ovule maturation and probably functions as nutrient storage for embryo development. The inner epidermis of the inner integument differentiates as the most conspicuous cell layer of the beet ovule. During growth and maturation of the ovule a system of small perinuclear vacuoles containing dense material increases steadily in these cells. At maturity this system fills up more than half of each cell and very dense material has accumulated in each vacuole. This vacuole content is highly refractive and contains tannins and/or polyphen

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00541.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

An ultrastructural investigation of the entire transmitting tract inTrimezia fosteriana(Iridaceae) was undertaken. The transmitting tissue is secretory but transfer cells do not occur at any level. With exception for the stigma papillae, the cells are covered with large amounts of secretory products. The papillae have a thick and ridged cuticle. The cuticle in the rest of the transmitting tract is thin and detached from the cell wall by the secretory products. It is more or less ruptured in the secretory parts of the stigma and ovary. In the stylar canal the major part of the cuticle is continuous and covers the secretory products. The occurence of a large amount of vesicles in the stigma transmitting tissue cells is interpreted as a result of high dictyosome activity. An electron opaque material is produced in the dictyosomes and appears in vesicles and vacuoles but also between the plasma membrane and the cell walls in the stigma. A small amount of such material is present in the cell walls. Corresponding material is also present in the style and the ovary but declines basipetally. Plastids with strongly electron opaque plastoglobules are present at all levels in the transmitting tract.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00542.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The outer epidermal walls of 65 species incorporated in 14 genera of the tribe Stapelieae were investigated by light and electron microscopy (TEM, SEM). The species, all of them stem succulents preferring the semi‐arid regions of the Palae‐otropics, possess an outer epidermal wall, which is relatively simple in structure. The whole plant body is covered by a massive wax layer, in addition some species bear wax crystals. A cutin layer follows beneath, reticulate over its whole expanse and not divided into a cuticle proper and cutinized layers. A cellulose layer, which often exhibits enclosed cutinbodies, delimits the wall against the plasmale

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00543.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb00544.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY