Stevia is a plant containing many active compounds, but usually propagated by stem cuttings because of low seed-yield-germination ability. The aim of this study was to investigate the impact of plant-growth regulators on stevia callus induction and growth from somatic tissue, as well as to determine the effect α-naphthalene acetic acid (NAA) and proline (PRO) on the amount of stevioside, rebaudioside A, phenols, flavonoids, and antioxidant activity. Stem and leaf segments were inoculated on a Murashige and Skoog (MS) medium supplemented with different concentrations of NAA and 6-benzylaminopurine (BAP) for callus genesis. The amount of steviol glycosides (SGs) was evaluated using high-performance liquid chromatography (HPLC), and the amounts of total phenols, flavonoids, and antioxidant activity by spectrophotometric methods. The highest callus-induction frequency and callus-mass increase were obtained from the leaf explants in MS medium supplemented with 2.0 μM NAA. The highest amount of SGs, phenols, and flavonoids, and stronger antioxidant activity were determined in the cellular compounds of callus from leaf explant. PRO reduced the amount of SGs and flavonoids. The significantly highest amount of total phenolic compounds was obtained in the callus from leaf explants in the medium supplemented with 2.0 µM NAA and 2.0 µM PRO.

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The effect of genotype, growth regulators and preconditioning of donor plants on callus induction in anther culture of flax was investigated. Anthers were cultured on modified MS medium supplemented with five different combinations of plant growth regulators. The results suggested that specific combinations of growth regulators must be designed for each genotype. Major differences between the present results and previous reports are discussed. The influence of sucrose concentration was also investigated. For flax cultivar, 'Mikael', callus induction was higher in medium supplemented with 1 mg l(-1) BAP and 2 mg l(-1) 2,4D containing 6% sucrose, while this combination of growth regulators significantly increased callogenesis in cultivars 'Lirina', 'Barbara' and 'Szaphir' when supplemented with 9% or 12% sucrose. The preconditioning of donor plants influenced callogenesis in subsequently isolated anthers. Anthers from donor plants grown at a lower temperature (18/14 degrees C) significantly increased callus induction over those from plants grown at a higher temperature (22/18 degrees C), although each genotype still required optimization of growth regulator combinations in the induction medium. Only 'Mikael' regenerated shoots when the callus was from induction medium supplemented with 2 mg I(-1) BAP and 1 mg l(-1) NAA.

The effect of culture media, explants and genotypes on adventitious shoot regeneration in spring rapeseed (Brassica napus L.) was examined. Hypocotyls and cotyledons of the doubled haploid lines NL-611, NL-662, NL-685 were induced to form callus by culturing on the Murashi geSkoog medium supplemented with different concentrations of 6-benzylaminopurine (BAP) and α-naphtylacetic acid (NAA) or zeatin and 2,4-dichlorphenoxyacetic acid (2,4-D). Adventitious buds were regenerated from the organogenic callus on the same medium. A large variation of shoot regenerability was observed, ranging within 0-37.5% for the frequency of bud formation and within 0-3.8 for the number of buds per explant. Generally, cotyledon-derived callus exhibited a higher bud regeneration frequency than hypocotyls, however, hypocotyl-derived callus developed a higher number of buds per explant. The maximum number of adventitious buds from hypocotyl-derived callus was obtained on a medium supplemented with 4.0 mg l -1 BAP and 0.05 mg l -1 NAA. Regenerated shoots were rooted in MS medium containing 0.1 mg l -1 NAA. Well rooted plantlets were acclimatized and subsequently established in soil.

The current study investigated the effect of genotype, growth regulators and type of carbohydrates on callus induction and indirect shoot regeneration in ovary culture of 8 linseed (Linum usitatissimum L.) cultivars. Callogenic response varied from 9.17% to 100% depending on the cultivars and medium composition interaction. The replacement of sucrose with a combination of sucrose + maltose significantly improved the callogenesis in 3 or 4 investigated cultivars, depending on growth regulators in the induction medium. The frequency of shoot formation from ovaryderived callus in 5 responsive cultivars ranged from 4.17% to 75.00%, whereas the other three cultivars tested did not exhibit any shoots. The replacement of sucrose with a sucrose + maltose combination in induction medium reduced or completely inhibited shoot formation frequency of responsive cultivars. The significantly highest mean shoot formation frequency (52.50%) was obtained from ovary-derived callus of the cultivar ʻMikael'. The analysis of variance revealed that cultivar (C), combination of growth regulators (GR), type of carbohydrates (CH) and their interaction significantly influenced callus induction and shoot formation frequency. In most cases, a higher shoot regeneration frequency was obtained when callus was from induction medium supplemented with 2 mg l -1 thidiazuron (TDZ) + 1 mg l -1 α-naphthylacetic acid (NAA) with 6% sucrose. Cytological analysis of root tips showed that 21.88% of the regenerated plants were haploids, while another group of regenerants (78.12%) were diploid and mixoploid.

Breeding linseed (Linum usitatissimum L.) using haploid techniques allows breeders to develop new cultivars in a shorter time period. Many research groups successfully created new linseed genotypes through anther culture; however ovary culture has been the subject of only a few earlier studies. In the present study, the effect of genotype and growth regulators combination on callus induction and shoots regeneration in ovary culture of nine commercially important linseed cultivars was investigated. Ovaries were cultured on modified MS medium supplemented with three different combinations of plant growth regulators. Variable callogenic responses were expressed by all of the genotypes tested on different induction media. The results suggested that specific combination of growth regulators for callus induction must be designed for each genotype. Shoot regeneration from ovary derived callus is a critical phase of the whole gynogenetic process. Differences in adventitious shoot formation frequency among genotypes were demonstrated and four responsive genotypes have been selected. Ovary derived callus from cultivar 'Mikael' manifested the highest adventitious shoot formation frequency with a high number of shoots per explant. The optimum ratio of growth regulators for shoot regeneration was shown to depend on the genotype. Cultivars 'Linola', 'Mikael' and 'Szaphir' showed the highest shoot regeneration frequency when callus had originated on induction medium supplemented with 2 mg L −1 BAP and 2 mg L −1 NAA, while combination of 1 mg L −1 BAP and 2 mg L −1 IAA promoted shoot formation in ovary-derived callus of 'Barbara'. The highest rate of shoots per explant has been obtained in second subculture.

Miscanthus x giganteus is a spontaneous sterile hybrid therefore the creation of useful genetic diversity by conventional breeding methods is restricted. Plant regeneration through indirect organogenesis may be a useful approach to create genetic variability of this important agricultural crop. The present study aimed to evaluate the effect of the explant type and growth regulators on indirect organogenesis of Miscanthus x giganteus and to determine the ploidy level of plant regenerants by flow cytometry. On average, the highest percentage of morphogenic callus tested explants formed in the medium supplemented with 2.5 mg L–1 IBA + 0.1 mg L–1 BAP + 4.0 mg L–1 l-proline. The most intensive secondary differentiation of callus cells was observed in the medium supplemented with 4.0 mg L–1 ZEA + 1.0 mg L–1 NAA. The highest root formation frequency with the highest number of roots was determined in the MS nutrient medium supplemented with 0.4 mg L–1 IBA, where more than 95% of plant regenerants survived and were growing normally.

This study aims to evaluate the ability of raspberry and blackberry pomace to inhibit lipid oxidation and prolong the refrigerated storage of beef patties. Berry pomace was incorporated into beef patties at the concentration of 1, 3, and 5%. Packed patties were stored for 9 days at 4 °C temperature and the quality of the meat was evaluated on the 0, 3rd, 6th, and 9th day. The natural mass loss during storage, the pH as well as the lipid oxidation were evaluated by thiobarbituric acid-reactive substance (TBARS) method. GC was used to determine the amount of fatty acids and e-nose, based on ultrafast gas chromatography, was used for the determination of volatile organic compounds in beef patties before and after the storage. The highest mass loss during refrigerated storage was observed in the control beef patties, while the berry pomace absorbed water and reduced the loss. The pomace additive influenced the decrease in the patties pH during the storage. Berry pomace can be very effective in relation to lipid oxidation, and as little as 1% of berry pomace influenced the decrease in the TBAR’s values in the patties stored for nine days by 3.06 and 2.42 times, depending on the pomace compared to the control patties. The use of berry pomace in meat products can reduce lipid oxidation, increase their fiber content and act as a thickener, as well as contribute to the usage of agri-food by-products.