Associação de fases meióticas e estádios dos micrósporos com características morfológicas de botões florais de pimentão

Abstract

In the present study, morphological characters adopted for floral bud selection used for androgenesis induction were associated with pepper (Capsicum annuum L. cv. Azeth) meiotic phases and microspore stages. Floral buds were harvested from greenhouse-grown plants and separated into six classes according to size relationships between calyx and corolla, and anthocyanin pigmentation in anthers. After sorting by size, buds were fixed using a methanol: acetic acid (3:1) solution at -20ºC. Cytogenetic preparations were mounted using an adaptation of an air-drying technique and staining through a phosphate buffer Giemsa solution. Bud observations were accomplished under a stereo-microscope and the cytogenetic preparations in an optic microscope. Recordings of floral buds and meiotic phases were performed with an image digitizing computer system. Variations on the meiotic phases were observed within each class. Although the approach based on anthocyanin pigmentation on anthers has been applied to another pepper varieties, it was not a reliable trait for determination of the microspore stage. Meiotic phases were citogeneticaly identified, although bud stage could not be associated with it. On the other hand, buds having the same calyx and corolla sizes presented a larger number of microspores in a suitable stage for anther culture.