摘要:

SUMMARYFrom observations of flower colour chimeras ofPetuniathe conclusion can be drawn that dominant alleles of corolla colour genes can only express themselves in those cells in which these alleles are present. Anatomical studies of shoot apices of eight‐day‐old seedlings show that at this stage of development of the plant three independent cell layers are already present in the shoot apex, viz., two tunica layers and a corpus. In his interpretation of the results of his transformation experiments withPetunia, Hess did not take the existing differentiation of the shoot apex in his seedling material into acco

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00910.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYThe structure of the shoot apex ofRotala rotundifoliais described with special attention to the initiation of leaf and axil bud primordia. A comparison is drawn between the vegetative shoot apex in aquatic and terrestrial plants and the apex of the inflorescence. The histogenesis of the apex is consistent with the tunica corpus hypothesis of Schmidt(1924). The zonation in the apex is clearly defined, easy to delineate, and stable. The number of apical initial cells is low. A quiescent zone has not been observed. All types of leaf are initiated in the second layer of the two‐layered tunica, very close to the centre of the apex. Corpus cells do not participate in the formation of the leaves. Buds in leaf‐axils are formed by derivatives of corpus‐cells surrounded by a two‐layered tunica.An axial procambial cylinder, provided with a pith, appears above the entry of the youngest leaf‐traces.It is concluded that the three types of apex inRotala rotundifolia(the vegetative apex in terrestrial and submerged plants and the inflorescence apex) are built up in the sa

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00911.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYDrimys winterihas an anatropous, crassinucellate type of ovule with two non‐vascularized integuments. Both the inner integument (i.i.) and the outer one (o.i.) are of dermal derivation. The integuments consist of three, or locally sometimes two or four layers of cells. The dermal initiation of the o.i. is in marked contrast with the subdermally initiated o.i. of the Magnoliaceae. This difference in origin of the o.i. is an additional character justifying the dissociation of the Winteraceae from the Magnoliacea

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00912.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYFour species ofAkanthomyces, collected on various arthropod hosts in Ghana, are described and illustrated.Akanthomyces gracilisSamson&Evans spec. nov. appeared to occur on a wide variety of insect hosts and is particularly common on ants.Akanthomyces pistillariaeformis(Pat.) Samson&Evans comb. nov. (=Isaria pistillariaeformisPat.) is often found on moths together withCordyceps tuberculata. The variability in synnematous habit and the associatedCordyceps tuberculatais discussed.Akanthomyces arachnophilus(Petch) Samson&Evans comb. nov. (=Trichosterigma arachnophilumPetch) was collected twice on spiders together withTorrubiella flavaPetch.A. aranearum(Petch) Mains is rather common on spiders.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00913.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYRates of transpiration and net photosynthesis in intact sugar beet and bean plants were measured during 14 hours' exposure to some herbicides, to transpiration inhibitors, and to high osmotic pressure.Transpiration and photosynthesis were inhibited to the same extent or transpiration slightly stronger, by treatment of the roots with ioxynil, by application of PMA and DSA either to the rooting medium or to the foliage, and by high osmotic stress. Photosynthesis, however, was inhibited to a greater degree than transpiration by simeton and isocil applied both to the roots and the leaves, and by a foliar spray of ioxynil. Similar, but somewhat smaller differences were found when DNOC was applied to the nutrient solution or to the leaves.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00914.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYFrom comparative investigations of five pretreatment‐extraction conditions, using the composition of the pool of free amino acids as a parameter of disintegration during the extraction procedure, it was found that the optimal conditions are: disintegration of the fresh plant material in liquid nitrogen (‐180°C), lyophilization and homogenization of the dried powder in the extraction medium at

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00915.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYWhen luxuriantly growingCuscutaparasitisedVicia fabaat the time of flowering, fruit setting of the host was generally completely inhibited. When the host was infected in a later stage of developmentCuscutaseriously interfered with further growth of pods.The process of translocation of14C‐assimilates from a photosynthesising leaf to other parts of the host and to the parasite was analysed. The process of assimilate withdrawal byCuscutaturned out to be so efficient that usually only negligible amounts of14C‐assimilates – or nothing at all – found its way into pods and seeds of the parasitis

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00916.x

年代:1974

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00917.x

年代:1974

数据来源: WILEY

摘要:

D. BurgerHzn.:Seedlings of some tropical trees and shrubs mainly of South East Asia, 399 pp., 155 figs. 1972. Pudoc, Wageningen. Price Dfl. 62.40.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00919.x

年代:1974

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00920.x

年代:1974

数据来源: WILEY