Abstract. Galactoglucomannan-derived oligosaccharides (GGMOs) (degree of polymerization 4-8) isolated from the wood of poplar (Populus monilifera Ait.) were shown to be inhibitors of the 2,4-dichlorophenoxyacetic acid-stimulated elongation growth of pea (Pisum sativum L. cv. Tyrkys) and spruce [Picea abies (L.) Karst] stem segments. A dependence on the concentration of GGMOs (between 10-5-10-1OM) as well as plant species was ascertained. Pea stem segments were much more sensitive (10-1OM) than spruce (10-8M). The GGMOs did not exhibit toxicity even at high concentrations and during long-term bioassays. The timing of the action of GGMOs and auxin in the growth process was also studied.

A mixture of galactoglucomannan-derived oligosaccharides (GGMOs), degree of polymerization 4-8, (--1.2 pM and =12 pM) stimulated the viability of spruce [Picea abies (L.) Karst] embryos predominately on media supplemented with indole-3-acetic acid: zeatin (0.01:1, 1:0.0l mg 9 1-1), at pH 5.0. Their effects on the development and morphogenesis of embryos were dependent on the culture conditions used. These GGMOs also improved the viability of spruce protoplasts when applied at the same concentrations in combination with 1-naphthaleneacetic acid, and to a lesser extent with 2,4dichlorophenoxyacetic acid at pH 3.8. Viability was also maintained in the presence of GGMOs when the growth hormones were absent; however, the efficiency of protoplast division was low.

No abstract

Eleven genotypes of sunflower were used to screen their regeneration potential in a meristem regeneration test. The inbred line HNK-81 showed the best regeneration of shoots directly from apical meristems and meristem derived calli, and rarely also the formation of adventious shoots from leaves of regenerated shoots.