Resposta androgênica de genótipos brasileiros de trigo a diferentes pré-tratamentos das espigas e a um agente gelificante

The objective of this work was to analyze the androgenic response of Brazilian wheat genotypes to different pretreatments of the spikes, prior to the culture of isolated microspores, and to the effect of a gelling agent in the induction culture medium. Five genotypes were evaluated for embryo formation, green plant regeneration, and spontaneous chromosome duplication. Wheat spikes were subjected to two pretreatments:cold, at 4°C for 21 days; and 2-hydroxynicotinic acid, at 32°C for two days. Culture media were evaluated with or without Ficoll as a gelling agent. Cold produced more embryos and green plants than the chemical pretreatment in four out of five genotypes. Only two genotypes treated with 2-hydroxynicotinic acid were able to produce plants, and one of them produced a single albino plant. Medium containing Ficoll produced more embryos than liquid medium and promoted a higher number of plants. Spontaneous chromosome duplication varies between genotypes and pretreatments, and shows high variability.