Browsing by Author "Olate, Eduardo"

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    Direct and indirect in vitro organogensis of Leucocoryne purpurea (Alliaceae) a chilean ornamental geophyte
    (SEJANI PUBL, 2008) Escobar, Luis H.; Jordan, Miguel; Olate, Eduardo; Barrales, Luis; Gebauer, Marlene
    In vitro shoot induction from callus and direct bulbil formation from shoots were obtained in Leucocoryne purpurea, an endemic vulnerable Chilean species. Basal leaf portions, bulb basal plate and root tips from in vitro gown plants were used as explants. Only bulb basal plate explants displayed morphogenic responses. Callus, shoot and bulbils developed on MS basal medium in the presence of various growth regulator combinations. Callus formation from bulb basal explants ranged between 40 to 100%; the highest response was observed in the presence of 4.5 or 13.6 mu M 2,4-D alone or 4.5 mu M 2,4-D in combination with 0.5 mu M BA after 4 months. Picloram alone or in combination with 2iP or BAP also supported callus initiation. Indirect shoot formation from callus occurred only after a further culture period of 2 months in MS medium containing 0.5 or 2.3 mu M TDZ. Basal bulb plate explants cultured in the presence of TDZ alone (0.5 and 2.3 RM, respectively) exhibited direct shoot formation within 90 days. After subculture in the presence of 0.5 mu M TDZ each single shoot formed new shoots (3 to 4) and new bulbils. However higher TDZ levels, up to 2.3 mu M, produced shoots with roots only, inhibiting bulbil formation, and the 4.5 mu M TDZ concentration caused necrosis.
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    Gamma irradiation on Alstroemeria aurea G. in vitro rhizomes: an approach to the appropriate dosage for breeding purposes
    (UNIV NACIONAL CUYO, FAC CIENCIAS AGRARIAS, 2012) Aros, Danilo; Valdes, Santiago; Olate, Eduardo; Infante, Rodrigo
    Gamma irradiation has been widely used as a breeding technique to obtain new cultivars in ornamental species such as Alstroemeria, where several cultivars have been obtained through rhizome radiation. The optimum dosage for an appropriate induction of mutation must be considered for breeding purposes and it depends mainly on plant susceptibility. Thus in this study in vitro cultured rhizomes of Alstroemeria aurea were irradiated with a gamma source using different dosages to evaluate the direct effect produced. Damage and number of rhizome sprouting were observed and recorded during 61 days after irradiation. At the end of this period, rhizomes were weighted and mortality was evaluated. Both mortality and weight increased depending on dosage. All irradiated rhizomes showed early sprouting in comparison with control (0 Gy) and no significant difference in final number of shoots after 61 days among irradiated treatments was observed. Bleaching and necrosis was observed in all irradiated rhizomes and was more evident at higher doses. LD50 was established at about 40 Gy and the optimum dosage to induce mutation was suggested between 2.5 and 5 Gy, when the growth was reduced in 50%, and probably this dosage could be used for breeding purposes.