Guide to the Aloes of South Africa

Abstract

Cytokinins in germinating maize caryopses L Transport and metaboiism of 8[^''Cjt-zeatin applied to the endosperm J. Van Staden Van Staden, J. 1981. Cytolcinins in germinating maize carj'opses. I. Transport and metabolism of 8['*C]t-zeatin applied to the endosperm. -Physiol. Plant. 53: 269-274.The transport and metabolism of 8["'C]t-zeatiii applied to the endosperm of Zea mays L. caryopses was studied. The applied zeatin was rapidly metabolised to a stable compound which co-eluted between adenine and dihydrozeatin on a Sephadex LH-20 column eluted with 10% methanol. This metabolite which was active in the soybean callus bioassay persisted in the endosperm tissue and was not transported in significant amounts to the embryonic axis during imbibition and early germination. Indications are that it can be exported during seedling establishment when nutrient mobilisation from the endosperm is more rapid. The results obtained indicate that cytokinins susceptible to oxidation apparently do not play a major role in the germination process of the maize kernel. If cytokirbins are at ail involved in the germination process of these propagules it would seem that their effect is more likely to be mediated by the dihydro derivatives of these hormones. These compounds do occur in mature maize fruits.

Conservation status of the recently reinstated Aloe davyana, A. davyana var. subolifera, and A. labiaflava (Asphodelaceae subfam. Alooideae), three maculate aloes endemic to South Africa

“…This aloe grows very well in disturbed areas and has been indicated as a species that can be planted on mine tailings and other disturbed areas to stabilise the soil and prevent erosion (Smith & Correia, 1988, 1992Van Wyk & Smith, 2014). Large stands in certain areas can be indicative of habitat degradation due to severe overgrazing (Glen & Hardy, 2000).…”

Morphological and cytogenetic characterization in experimental hybrid Aloe jucunda Reyn. x Aloe vera (L.) Burm. f. (Asphodelaceae)

“…Specimens of A. jucunda (P2) were originally acquired in local nurseries and those of A. vera (P1) came from Península de Araya naturalized population, located at 10°34'15 '' N and 64°12'08'' W (Albornoz and Imery 2003). Both species were identified considering the morphotaxonomic descriptions of Jacobsen (1955), Carter (1994) and Van-Wyk and Smith (1996). Five specimens of each of the evaluated genotypes were deposited in the IRBR Herbarium.…”