D. Svetleva

Regeneration Possibilities of Bulgarian Bean Cultivars Plovdiv 11M and Dobrudjanski 7

ABSTRACTStudy was conducted with Bulgarian mutation cultivar Plovdiv 11M and Bulgarian bean standard Dobrudjanski 7. The effect of cytokinins BAP and TDZ in combination with NAA on different concentrations was tested. The regeneration capacity of explants—leaves, hypocotyls and cotyledons, isolated from mature and immature seeds was compared. The best regeneration ability demonstrated immature cotyledons on culture medium MS with addition of 10 μM BAP. The regeneration possibility of both cultivars was in strong dependence on genotype, concentration of the auxin: cytokinin ratio, physiological status and the type of the explants. Present study is the first report for a successful regeneration of Bulgarian dry bean cultures (Phaseolus vulgaris L.).

Phaseolus Vulgaris L. Somatic Embryos Induction in Liquid Medium

ABSTRACTBulgarian common bean (Phaseolus vulgaris L.) cultivars: the standard—Dobrudjanski 7 and the mutant—Plovdiv 11M were used as the donor genotypes. Direct somatic embryos have been induced from different explants (roots, hypocotyls, primary leaves and epycotyls or leaf petioles) in liquid media (modified B5), containing different concentrations of 2.4-D. Amount and the quality of induced embryos depends on the genotype, the concentration of 2.4-D and the type and age of the explants. Conversion and germination of bean embryo development are crucial and have to be optimized.

Factors Influencing the in Vitro Cultivation of Common Bean (Phaseolus Vulgaris L.) Leaf Petioles

ABSTRACT The influence of genotype, explants age and medium on in vitro cultivation of common bean (Phaseolus vulgaris L.) leaf petioles was investigated. Bulgarian cultivars Doubru-djanski 7; Plovdiv 11M and Plovdiv 10 were used in the experiments. Leaf petiole explants arising from in vitro seedlings were cultivated on modified MS media containing different amounts of TDZ, Paclobutrazol, NAA, BAP, IBA and GA3 in different combinations. Explants development in different ages (5-; 7- and 14-days old) on the investigated media was genotype dependent. Bi-factorial ANOVA and three-factorial analyses were used for evaluation of the results that precisely disclosed the factors interactions. The applied 3-factorial dispersion analysis revealed that the interaction between factors genotype-explant age (AB) and the threefold interaction genotype-explant age-media (ABC) exerted the strongest influence on the explant development and callus formation. The influence of interaction between factors genotype-explants age (AB) increase along with cultivation time. No dependence was found between the size of initial plants, leaf petiole position (near to the leaf or to the steam), explant fresh weight, their development and quantity of formed callus. An additional experiment with precultivated sterile seeds on media containing 1 μM IAA or 1 μM BAP (on the base of MS) contributed. Better explant development was observed in comparison to their cultivation only on MS medium.

In Vitro Cultivation and Regeneration of Bean (Phaseolus Vulgaris L.)

ABSTRACT Possibilities and limitations concerning in vitro regeneration of bean (Phaseolus vulgaris L.) based on the existing literature data were discussed. Some parallels between traditional breeding methods applied for creation of new bean cultivars with valuable agricultural traits and in vitro biotechnological approaches was made. Authors present the next main areas of tissue culture that are more possible to be used for bean improvement: A) Micropropagation, and morphogenesis; B) Somatic tissue and cell manipulations; C) Protoplast isolation; D) Anther culture and E) Embryo rescue. A conclusion along with original hypnotizes concerning difficult regeneration, low efficiency and repeatability of biotechnological methods in Phaseolus vulgaris was presented at the end of the manuscript.

Seed Precultivation on Media Supplimented with Different Hormones and Its Influence on Callus Growth in Common Bean (Phaseolus Vulgaris L.)

ABSTRACT The influence of common bean seed precultivation on media supplemented with different hormones was investigated on callus growth at three consistent passages. Seed precultivation was performed on MS medium with 30 g/L sucrose and 7 g/L agar. Different treatments were performed on this medium with application of: Fluridone (1 μM); ABA (1 μM); CPPU (2μM) and BAP (1 and 100 μM). Leaf petioles of 7-days old sterile plants from Bulgarian cultivars Dobroudjanski 7; Plovdiv 11M and Plovdiv 10 were used as explants for in vitro cultivation. Expiants were cultured on media MSI2 (TDZ—2,64 mg/L; NAA—0,372 mg/L); MSE (BAP—0,700 mg/L; IBA—0,001 mg/L) and MS0. Genotype dependent reaction to seed precultivation at different media was found. Seed precultivation on media with 100 μM BAP increased the explant weight and it is the highest for the three investigated cultivars only at the first passage. Higher regeneration possibilities, depending of the genotype, were created after seed precultivation on media BAP1 (1 μM); ABA (1 μM) and MSI2. Results were mathematically calculated by bi-factorial ANOVA analysis. Single effect of passages and media is higher than that of interaction between them.