The influence of ethylene used in combination with Thidiazuron (TDZ), silver nitrate (AgNO3) and acetylsalicylic acid (ASA) was evaluated on sweet pepper androgenesis of F1 genotypes (PIX21C12#35 x Agronômico 08, PIX21C04#4 x Line 004, PIX22C#31 x Line 004, PIX21C15#45 x Ikeda and PIX22C#21 x Ikeda). Floral buds were collected when sepals and petals were approximately of equal size, corresponding to the uninucleated stage of microspores. Anthers were placed in Petri dishes containing three mediums: C medium supplemented with TDZ (4.5mM); C medium plus 2,4-D (0,05mM), Kinetin (0.5mM) and ASA (88,8mM) or AgNO3 (5.0 mg/L). After inoculation, the anthers were kept in the environment with ethephon for 0, 2, 4, 6 or 8 days at 35ºC for eight days in the dark. The experiment was conducted in a factorial design with four replications. Each replicate consisted of one Petri dish containing 20-24 anthers. TDZ and AgNO3 were most effective for inducing somatic embryos after four days with Ethrel. The greatest rates of necrosis took place on the medium with AAS. Direct regeneration of plantlets occurred only on medium supplemented with 5 mg/L of AgNO3 after an eight-day treatment with Ethrel. The most responsive genotypes were PIX22C#31 x Line 004 and PIX22C#21 x Ikeda. Chromosome number of the seedlings was verified through the root tip analysis which indicated the presence of haploid and diploid chromosome number. Since regeneration was direct, ie without going through callus phase, it is hypothesized that the diploid seedlings came from in vitro diploidization.
Capsicum annuum L.; breeding; biotechnology; tissue culture
