摘要:

SUMMARYInterpairings were made of nine strains ofPythium splendens. In seven strains a heterothallic response could be shown, while two strains also produced oogonia in single culture.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00589.x

年代:1969

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00590.x

年代:1969

数据来源: WILEY

摘要:

SUMMARYIn this paper the results of a palynological investigation of a 120 m deep borehole in the Tenaghi Philippon, Macedonia (Greece) are given. These data show that during the Holocene mainly an oakwood forest was present. In the most recent part of the HoloceneFagusandAbieswere also present. During the climatic extremes of the Weichselian an open vegetation existed. During the early interstadials a forest withQuercus, FagusandCarpinusexisted, whereas in the later interstadials stands ofPinuspredominated. In the Late Glacial a not very dense oak forest was of some importance.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00591.x

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe geotropic response of horizontal intact pea seedling roots was rapidly influenced by indole‐3‐acetic acid (IAA), which was applied in narrow rings of lanolin paste a few cm from the apex. The applied auxin thus likely was transported in the acropetal direction in these roots. The influence of IAA was strongly reduced when 2, 3, 5‐triiodobenzoic acid (TIBA) was applied to the roots at the apical side of the IAA‐ring. When TIBA was applied alone at various distances from the apex of the horizontal roots it also inhibited the geotropic curvature. The transport of auxin in the apical region of horizontal roots probably occurred both in the acropetal and in the basipetal di

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00592.x

年代:1969

数据来源: WILEY

摘要:

SUMMARYCrude extracts from roots of pea and cucumber have different pH optima for IAA‐oxidase activity, which are caused by the different natural thermostable cofactors present in the two extract

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00593.x

年代:1969

数据来源: WILEY

摘要:

SUMMARYCrossing experiments were carried out between the three cytotypes (2n = 24, 2n = 40 and 2n = 48) ofSymphytum officinaleand that ofSymphytum asperum(2n = 32). The results indicate that morphologically closely related types are sometimes crossable, whereas in other cases no hybrids could be produced. On the other hand morphologically very distinct types could be crossed with great ease.The significance of these studies for the elucidation of taxonomic problems is discussed.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00594.x

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe germination rate of turions produced in a medium without gibberellic acid depends on the time the turions spend in this medium. Gibberellic acid in light enhances the germination rate of turions harvested when turion production has just started. Kinetin enhances the germination of such turions in light and in darkness. The highest germination rate in light is obtained when both kinetin and gibberellic acid are added to the medium.Turions produced in a medium with gibberellic acid do not require a cold treatment for rapid germination in light and darkness.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00595.x

年代:1969

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00596.x

年代:1969

数据来源: WILEY

摘要:

SUMMARYIn this third report of this series concerning biosystematic studies of the Dutch halophilous species ofSpergularia, the relation between the variation and the environment is discussed. In the case ofS.media, a correlation between the occurrence of populations with a high representation of plants with unwinged and subalate seeds and the degree of extremity of the abiotic factors prevailing in the habitat seems to be manifest. In some cases overgrazing by sheep or cattle also results in a relatively high representation of such plants in the population, even if the abiotic factors are favourable. The possible causes of a selective advantage of winged seeds over exalate seeds in certain types of habitats (andvice versa) are discussed. The predominantly autogamousS. marinaoccurs in populations consisting of plants with unwinged seeds. However, one population was found containing plants with winged seeds; the possible ecological causes of this phenomenon are mentioned.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00597.x

年代:1969

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1969.tb00598.x

年代:1969

数据来源: WILEY