Using four Polish Vicia faba L. minor cultivars (Bronto, Dino, Tibo, Nadwiślański) we obtained callus from epicotyl fragments collected from 7- and 14-day-old seedlings and from cotyledonary nodes of immature seeds. Callus induction efficiency varied from 81% to 97% depending on the origin of the explant. Shoots regenerated only from the cotyledonary nodes of all tested cultivars. On average, 50% of the explants grown on MS medium containing 1.0 mg dm-3 NAA, 0.5 mg dm-3 BAP, 0.25 mg dm-3 GA3, 1.0 g dm-3 casein hydrolysate, 750 mg dm-3 inositol, 3% sucrose and 0.4% agar were able to regenerate shoots. The number of calluses regenerating shoots was highest from explants collected from fruiting nodes 6 to 9. Decapitation of donor plants increased the percentage of calluses regenerating shoots. On half-strength MS medium with 2 mg dm-3 NAA and on 1/2 MS alone, 11% of the shoots rooted; on 1/2 MS with 1 g dm-3 AC, 8.0% rooted. The regenerants were transferred to Perlite with Hoagland medium and acclimated. Ten percent of the regenerated plants survived the acclimation process, flowered and produced seeds.
Plant tissue culture techniques have become an integral part of progress in plant science research due to the opportunity offered for close study of detailed plant development with applications in food production through crop improvement, secondary metabolites production and conservation of species. Because the techniques involve growing plants under controlled conditions different from their natural outdoor environment, the plants need adjustments in physiology, anatomy and metabolism for successful in vitro propagation. Therefore, the protocol has to be optimized for a given species or genotype due to the variability in physiological and growth requirement. Developing the protocol is hampered by several physiological and developmental aberrations in the anatomy and physiology of the plantlets, attributed to in vitro culture conditions of high humidity, low light levels and hetero- or mixotrophic conditions. Some of the culture-induced anomalies become genetic, and the phenotype is inherited by clonal progenies while others are temporary and can be corrected at a later stage of protocol development through changes in anatomy, physiology and metabolism. The success of protocols relies on the transfer of plantlets to field conditions which has been achieved with many species through stages of acclimatization, while with others it remains a challenging task. This review discusses various adjustments in nutrition, physiology and anatomy of micro-propagated plants and field grown ones, as well as anomalies induced by the in vitro culture conditions.
The effects of gamma irradiation on the vernalization requirements, growth and development of winter wheat grown in a rainout shelter were studied during two successive growing seasons. Dry grains of winter wheat cv. Kobra were irradiated with 300 Gy radiation from a cobalt 60 gamma irradiator. Treated and control grains were pregerminated and subjected to vernalization for 0, 42 or 54 days. Morphological parameters of the plants developing from irradiated seeds (M1 generation) and the plants grown from the seeds produced by the irradiated plants (M2 generation) were measured in order to track the studied effects over two generations. Irradiation of dry grains slowed the growth and development of the plants regardless of the temperature treatment. The measured yield structure elements appeared to be lower for irradiated plants, but no clear effect of radiation on vernalization requirements was noted