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  • Author: Iwona Pawelec x
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Ewa Dziadczyk, Marcin Domaciuk, Piotr Dziadczyk, Iwona Pawelec, Ewa Szczuka and Józef Bednara

Abstract

The purpose of our investigation was to determine appropriate conditions for induction of raspberry (Rubus idaeus cv. Nawojka) cell suspension culture. The established callus culture obtained from leaf explants was used as an inoculum for cell culture initiation. Five combinations of plant growth regulators: 1) 4.0 mg l-1 IAA and 1.0 mg l-1 BAP; 2) 0.25 mg l-1 2,4-D; 3) 0.5 mg l-1 2,4-D; 4) 2.0 mg l-1 NAA and 2.0 mg l-1 BAP; 5) 4.0 mg l-1 NAA and 2.0 mg l-1 BAP, added into modified Murashige and Skoog (1962) medium, were tested in order to get the callus culture suitable for initiation of a cell suspension. The best callus (vigorously growing, healthy and friable) was obtained on the medium supplemented with 4.0 mg l-1 IAA and 1.0 mg l-1 BAP. To find the appropriate culture conditions for dispersing callus tissue in liquid medium into single cells and small aggregates, four combinations of plant hormones (auxins and cytokinins) were tested. The best culture medium for induction of raspberry cv. Nawojka cell suspension appeared to be the one supplemented with 1.0 mg l-1 2,4-D. Also the medium with 8.0 mg l-1 IAA and 1.0 mg l-1 BAP was similarly efficient.

Open access

Sandra Paszkiewicz, Iwona Pawelec, Anna Szymczyk and Zbigniew Rosłaniec

Abstract

This paper presents a comparative study on which type of platelets nanofiller, organic or inorganic, will affect the properties of thermoplastic elastomer matrix in the stronger manner. Therefore, poly(trimethylene terephthalate-block-poly(tetramethylene oxide) copolymer (PTT-PTMO) based nanocomposites with 0.5 wt.% of clay (MMT), graphene nanoplatelets (GNP) and graphene oxide (GO) have been prepared by in situ polymerization. The structure of the nanocomposites was characterized by transmission electron microscopy (TEM) in order to present good dispersion without large aggregates. It was indicated that PTT-PTMO/GNP composite shows the highest crystallization temperature. Unlike the addition of GNP and GO, the introduction of MMT does not have great effect on the glass transition temperature of PTMO-rich soft phase. An addition of all three types of nanoplatelets in the nanocomposites caused the enhancement in tensile modulus and yield stress. Additionally, the cyclic tensile tests showed that prepared nanocomposites have values of permanent set slightly higher than neat PTT-PTMO.