Plant Biology

Groeneveld, H. W.

doi: 10.1111/j.1438-8677.1976.tb01048.xpmid: N/A

A method is described for the isolation, purification and extraction of the triterpene particles of Hoya australis R. Br. ex Traill. (Asclepiadaceae) and Euphorbia milii Desm. (Euphor‐biaceae).

Stegenga, H.; Borsje, W. J.

doi: 10.1111/j.1438-8677.1976.tb01049.xpmid: N/A

The morphology of Acrochaetium dasyae Collins is described in detail from material collected along the Dutch coast. This material consists of predominantly unisexual gametophytes with a prominent persistent basal spore and a multicellular filamentous prostrate system, which may be more or less endophytic in Dasya pedicellata (C. Ag.) C. Ag.. Some additional remarks are made on field‐collected specimens of A. dasyae from Swedish and Eastern‐Canadian coasts. The life‐history was completed in culture and turned out to be a diplobiontic cycle consisting of slightly heteromorphic generations. Gametophyte and tetrasporophyte differ in persistence or non‐persistence of the basal spore, and to a lesser degree in morphology of the basal system and arrangement of the monosporangia.

Kakes, P.; Everards, K.

doi: 10.1111/j.1438-8677.1976.tb01050.xpmid: N/A

The genetics of flower colour was studied in two subspecies of Viola calaminaria. One major gene could account for the “yellow‐blue” phenotype, if we assume that inheritance is tetrasomic.

Van Hasselt, Ph. R.

doi: 10.1111/j.1438-8677.1976.tb01051.xpmid: N/A

The possible protection against photo‐oxidative degradation of chlorophyll and carotene in Cucumis leaf discs at 1°C by a wide variety of compounds was investigated. Dimethyl sulphoxide and glycerol as well as ferricyanide, ascorbate, KCN and hydroxylamine were ineffective. Photo‐oxidation was, however, at least partly, prevented by benzoquinone, hydroquinone, naphtoquinone, guajacol, benzidine, diaminobenzidine, alizarinesulphonicacid, triphenyltetrazoliumchloride and 3‐(3,4‐dichlorophenyl), 1,1‐dimethylureea. Photo‐oxidative damage was promoted by salicylaldoxine, disalicylidenediaminopropane, azide, ethylenediamine tetraacetic acid, trishydroxymethylaminomethane, diquat and benzylviologen. It was also increased at high pH values. It is suggested that the mechanism of protection of Cucumis leaf chloroplasts against low temperature photo‐oxidative damage is a protection of the electron transport pathway from the reducing to the oxidizing side of the photosystems.

Huisinga, B.

doi: 10.1111/j.1438-8677.1976.tb01052.xpmid: N/A

Irradiation with red light enhances growth and geotropic curving of decapitated Avena coleoptiles. The regeneration of a physiological tip appears to be retarded which indicates an increase of available auxin in the subapical parts of the coleoptile.

Schenk, E.

doi: 10.1111/j.1438-8677.1976.tb01053.xpmid: N/A

Cycloheximide (CHM) inhibits translocation of 14C‐α‐amino‐iso‐butyric acid in excised leaves of Sagittaria graminea, but does not affect its uptake. Protein synthesis was also inhibited by CHM.

Hammans, J. W. Kleinen; Thomas, J. B.

doi: 10.1111/j.1438-8677.1976.tb01054.xpmid: N/A

The relative amounts of chlorophyll b (Cb) and various chlorophyll a (Ca) forms in nine plant species were determined by computer analysis of low‐temperature absorption spectra.

Van Zeist, W.

doi: 10.1111/j.1438-8677.1976.tb01055.xpmid: N/A

Charred rye grains recovered from two settlement sites indicate that in the Netherlands, Secale cereale was grown by native farmers in the first centuries A.D. and probably already in the last centuries B.C.

Hagendijk, A.; Van Soest, J. L.; Zevenbergen, H. A.

doi: 10.1111/j.1438-8677.1976.tb01056.xpmid: N/A

Fourteen new species belonging to Taraxacum sect. Vulgaria Dahlst. are described and their area of distribution is given: T. angulare, T. arenarium, T. armatifrons, T. ekmaniiforme, T. flandricum, T. lancidens, T. nitidum, T. pachymeroides, T. planoides, T. recessum, T. retusum, T. texelense, T. tortuosum and T. unguifrons.

Bredemeijer, G. M. M.

doi: 10.1111/j.1438-8677.1976.tb01057.xpmid: N/A

The pollination‐induced wave of peroxidase isoenzyme 10 activity in mature Nicotiana alata styles does not occur in immature styles unless pollinated within one day before anthesis. The capacity of a style to increase peroxidase 10 activity arises at the same time as the shift from compatibility to incompatibility. In styles selfed at 4 days after anthesis the peroxidase 10 wave is transmitted with a higher speed as compared to styles selfed at anthesis.