The aim of this study was to assess genotype by environment interaction for seed quality traits in interspecific cross-derived Brassica lines by the additive main effects and multiplicative interaction (AMMI) model. The study comprised of 25 winter rapeseed genotypes i.e.: B. napus cultivar Californium, twenty three cross-derived Brassica lines and male sterile line of an F 8 generation of B. napus (MS8), selected from resynthesized oilseed rape (B. rapa ssp. chinensis 9 B. oleracea var. gemmifera) using in vitro cultures of isolated embryos. Field trials were performed at three locations in 3 years in a randomized complete block design, with three replicates. AMMI analyses revealed significant genotype and environmental effects as well as genotype by environmental interaction with respect to all five observed traits. The lines 16 (B. napus line MS8 9 B. rapa ssp. pekinensis) and 7 (B. napus line MS8 9 B. carinata) are recommended for further inclusion in the breeding programs because their stability and good average values of observed traits, except total glucosinolates content for line 16 (the best total genotype selection indexes were equal to 81 and 97, respectively).

The aim of the present study is to determine the influence of different concentrations of growth regulators on the hypocotyl explants regeneration abilities of flax cultivars (Linum usitatissimum L.). Plant material used in the study was obtained from two flax cultivars: Modran and Selena. Hypocotyl explants were obtained from 6-dayold seedlings and were subsequently placed on basal MS (Murashige and Skoog 1962) medium and MS medium supplemented with 6-benzylaminopurine (BAP) or naftalene acetic acid (NAA). Final evaluation of the callus, the shoot and the root formation of the explants was performed 28 days after the experimental setup. The highest regeneration effectiveness was observed on the media supplemented with 1 mg/l BAP.

The purpose of this work was to assess the impact of zearalenone (ZEN) and selected hormone regulators on the effectiveness of microspore embryogenesis in anther culture of wheat. The plant material comprised F1 hybrids of winter and spring wheat. Six combinations of media inducing microspore proliferation and formation of embryogenic structures were investigated: two combinations of growth regulators (D - 2,4-D + dicamba, K - 2,4-D + kinetin), each with three ZEN concentrations (0 mL/L, 0.1 mL/L, 0.2 mL/L). A significant increase in microspore embryogenesis effectiveness on media with the addition of ZEN was observed both at the stages of its induction and the formation of green plants in some genotypes. In case of both combinations of growth regulators, an increased concentration of ZEN resulted in more effective induction of microspore embryogenesis. The most effective induction medium was the D medium supplemented with 0.2 mL/L ZEN. As a result of the use of zearalenone together with two combinations of growth regulators, all genotypes tested produced androgenic structures, which indicates the breakdown of genotypic recalcitrant in the analysed hybrids. In addition, green plants were obtained from 18 out of 19 tested hybrids. The addition of ZEN to the medium did not affect the number of regenerated albino plants nor the number of spontaneous genome doublings proportion.

Clubroot, caused by the protozoan parasite Plasmodiophora brassicae Woronin, is one of the most damaging diseases of Brassica napus worldwide. Resistant plant material is valuable for cultivation in all areas of high incidence of the disease and intensive growth of oilseed rape. We have evaluated clubroot resistance, plant morphology and seed quality in 15 lines of an F 4 generation and selected six lines of F 5 generation of interspecific hybrids obtained from a cross between a male sterile line of B. napus 'MS8', selected from resynthesized oilseed rape (B. rapa ssp. chinensis × B. oleracea var. gemmifera) and an ecotype of B. rapa ssp. pekinensis. Clubroot resistance was evaluated using a bioassay with P 1 -P 5 pathotypes of P. brassicae (according to the classification of Somé et al. 1996). The resistance to the pathotype P 1 was successfully fixed in the F 5 generation, and improved in some lines in respect to the pathotypes P 2 -P 4 . The resistance to P 1 and the other tested pathotypes was not linked. Characterization of plant material included recent techniques of FISH and BAC-FISH with a special focus on the analysis of ribosomal DNA (rDNA) of selected individuals. Two hybrid lines combined high levels of resistance with appropriate plant morphology, good seed quality traits and a stable chromosome number and arrangement. Recent techniques of 'chromosome painting' provided good insight into chromosome organization in the hybrids obtained, and offered opportunities of further improvement of the breeding process.

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