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Genotype, type of explant and concentration of growth regulators have been studied to increase efficiency in plant regeneration of Phaseolus vulgaris L. However, studies on the effect of the gelling agent in shoots induction are not enough. Therefore, the present study aimed to determine the effect of gelling agent on organogenic calli proliferation and shoots regeneration of P. vulgaris cv. 'BAT-93', 'BAT-304', 'BAT-482', 'Ica Pijao' and 'CIAP 7247F'. Callus fresh weight (g) was determined. Number of calli with shoots, number of shoots per callus and number of hyperhydric shoots was measured in shoots regeneration. Results showed that gelling influenced the calli multiplication and shoot regeneration in the five cultivars. 'Ica Pijao', 'CIAP7247F' and 'BAT-93' showed the highest values in calli fresh weight (g) using microbiological agar E. Besides, 'BAT-482' reached the highest value of fresh weight of calli in culture medium hardened with gelrite. 'BAT-304' calli showed similar values of fresh weight in both treatments. During regeneration, cultivars 'BAT-93' and 'CIAP 7247F' showed the highest values in the number of callus with shoots and shoots per callus in culture medium solidified with gelrite. Nevertheless, in this treatment there were more hyperhydric shoots regardless the cultivar. [ABSTRACT FROM AUTHOR]

The henequen (Agave fourcroydes Lem.) is a plant of a great economic and ecological value. The current technologies used for its micropropagation require a bigger efficiency, due to difficulties that take place, mainly during the multiplication phase. The objective of this work was to achieve the formation of axillary shoots with a reduction of the concentrations of growth regulators and a decrease in the number of hyperhydric shoots. Shoot tips of henequen established in vitro for 35 days were used to induce the formation of axillary shoots . The influence of different agar concentrations and the use of different combinations of plant growth regulators (IBA, TDZ and 6-BAP) were tested to 45 days. The highest efficient in the axillary shoot multiplication and minimal occurrence of hyperhydricity of the plants during the process were achieved in the culture medium with1.0 mg.l-1 of IBA, 1.0 mg.l-1 of 6-BAP, 0.5 mg.l-1 of TDZ and hardened with 8.0 g.l-1 of agar. [ABSTRACT FROM AUTHOR]