We describe the multi-step regeneration system of medicinal plant Schisandra chinensis (Turcz.) Baill. The seeds were pre-treated with 0.005 µM thidiazuron. Subsequently the zygotic embryos of the early heart stage were cultured on medium with 50 µM of 2,4-dichlorophenoxyacetic acid (2,4-D) and after three weeks the embryogenic calli were transferred to a medium with 10 µM of 2,4-D and 4 µM of 6-benzyladenine and were sub-cultured at the 4-week intervals. Abscisic acid (30 µM) and polyethyleneglycol (3 %) significantly influenced the synchronization of development of the somatic embryos (SEs) to the globular stage. The following culture on a medium without growth regulators resulted in full developed cotyledonary stage SEs. Indole-3-butyric acid (0.05 µM) contributed to their rapid conversion to plantlets.

Paenibacillus mendelii sp. nov., from surfacesterilized seeds of Pisum sativum L. Institute of Public Health in Ostrava, Partyzá nské ná m. 7, 702 00 Ostrava, Czech Republic A Gram-variable, facultatively anaerobic, endospore-forming bacterium was isolated from surface-sterilized seeds of the garden pea and characterized with phenotypic and molecular methods. A PCR with the Paenibacillus-specific primer PAEN515F and the 16S rRNA gene sequence indicated that strain C/2 T belongs to the genus Paenibacillus and is closely related to Paenibacillus phyllosphaerae (94?0 % sequence similarity). Strain C/2 T generated a unique phenotypic profile, in particular for the production of acid from substrates. The DNA G+C content (50?8 mol%) and the major fatty acid (anteiso-C 15 : 0 ) are consistent with the genus Paenibacillus. DNA-DNA hybridization distinguished strain C/2 T from other phylogenetically related Paenibacillus species and, therefore, strain C/2 T (=CCM 4839 T =LMG 23002 T ) is here described as the type strain of a novel species, for which the name Paenibacillus mendelii sp. nov. is proposed.The garden pea (Pisum sativum L.) has been one of the model organisms used for tissue culture and transformation studies at Mendel University of Agriculture and Forestry in Brno (Czech Republic). Cultivation and regeneration in vitro of Pisum sativum 'Caesar' were especially difficult because of frequent latent contaminations. The hazard analysis critical control point system (Leifert et al., 1994) was applied to detect sources of contamination. An unknown bacterium, strain C/2 T , was detected as being a source of contamination. This strain was isolated in February 2001, from surface-sterilized seeds of the garden pea. This finding is in agreement with the observation of Leifert et al. (1994), who reported micro-organisms surviving the surface sterilization of plant material. Elvira-Recuenco & Van Vuurde (2000) also proved that various bacteria are abundant in pea cultivars. Characterization of the 16S rRNA gene sequence indicated that strain C/2 T is a member of the genus Paenibacillus (Ash et al., 1993). An analysis of 16S rRNA gene sequence similarity (<97 %) indicated that strain C/2 T differs from all currently recognized species of the genus Paenibacillus.Seeds of the garden pea, Pisum sativum 'Caesar', harvested in 1999 at Agritec (a seed-producing company in Šumperk, Czech Republic), were used in the experiment. A sample of 1 kg seeds was surface sterilized for 1 min with 70 % ethanol; this was followed by vigorous shaking in 15 % household bleach (Savo -5 % sodium hypochlorite; Bochemie) for 15 min (Saettler et al., 1989). The seeds were than rinsed three times in sterile double-distilled water, ground and then soaked in sterile double-distilled water for 3 h. The supernatant was filtered through a 0?2 mm Supor membrane disc filter (Gelman). The filter discs were placed on nutrient agar plates containing 523 medium (Viss et al., 1991) and/or Leifert Waites sterility test medium (Leifert et al., 1994) and incubate...