摘要:

SUMMARYFactor analysis is introduced into autecological research as a helpful method in order to interpret the results of investigations in which a lot of variables per individual, population, or species must be determined one or several times during the period of growth. Growth patterns of different individuals, populations, or species can simply be compared with each other. This is illustrated in two examples with reference toChamaenerion angustifolium, and related to the distinction of ecotypes.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00882.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYOperation of the pollination mechanisms ofPedicularis palustrisL. by nectar and pollen foraging bumblebees (BombusLatr.) was studied. It was found that pollination could be achieved in two ways:by normal collectors, viz. long‐tongued bumblebees;by nectar thieves, viz. short‐tongued bumblebees.Normal collectors (Bombus muscorumL.,B. pascuorum floralisGmel. andB. hortorumL.) introduced their head and tongue into the 12 mm corolla tube to secure nectar, while stigma and style swept the forager's head and thorax. Nectar thieves (Bombus jonellusKirby, B.terrestrisL. andB. lucorumL.) obtained nectar through holes in the corolla tube made by the latter two species. Pollen collecting thieves pushed against the upper lip while hovering in the air. Thus pollen was released and dusted on venter and legs. This foraging behaviour was attended by a hissing sound, presumably caused by wing vibrations.Both ways of pollination resulted in large‐scale seed‐setting, thus contradicting the common interpretation that nectar thieves do not effect pollination and seed pro

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00883.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYNine new species belonging toTaraxacumsect.VulgariaDahlst. are described and their area of distribution is given:T. brabanticum, T. flevoense, T. hamatulum, T. lucidiforme, T. ploegii, T. subarmatum, T. subditivum, T. subericinumandT. tarachodum.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00884.x

年代:1973

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00885.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYA new species of the genusDactylariaSacc. is described and figured. It differs from all described species by its production of two kinds of conidia.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00886.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYThis paper describes an ALGOL‐60 computer program for computation and graphical representation of pollen analytical data. The program offers the possibility of computing and drawing relative frequencies, values per unit of sediment and values per unit of sediment per unit of time. An input description is include

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00887.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYThe pollen morphology of some Eurasiatic species of the genusQuercuswas studied by means of scanning electron microscopy. Three major pollen types can be distinguished. The relation between these pollen types and the evergreen and deciduous habits is discussed, as well as their taxonomic significance.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00888.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYPedicel abscission of flower buds is retarded by the presence of the bud and by IAA, the buds probably preventing abscission by auxin production. Ethylene removes the retarding effect of the buds and also accelerates the abscission of pedicel explants without buds. ABA has a small accelerating effect, gibberellic acid and kinetin are inactive. The presence of vegetative plant parts enhances the abscission rate, mainly by the supply of nutrients. The difference in flower bud abscission between threeBegoniaclones depends on a difference in the pedicels which is probably not hormonal in nature.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00889.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYThe influences of indoleacetic acid (IAA), abscisic acid (ABA), and ethylene on the abscission ofBegoniapedicels were studied by estimating the periods of sensitivity to them and by analyzing their interactions.Except for the alternation of sensitivity to IAA and to ethylene, the hormones affect the abscission independently from one another.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00890.x

年代:1973

数据来源: WILEY

摘要:

SUMMARYThe abscission inBegoniapedicels was studied anatomically. The abscission zone, consisting of small, non‐elongated cells, is present already in very young pedicels. The separation proceeds from the outside inward. The pattern is identical in three different clones and is not affected by growth regulators delaying or accelerating the abscissio

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1973.tb00891.x

年代:1973

数据来源: WILEY