Conservação e viabilidade de pólen em cana-de-açúcar

Abstract

The genetic variability of sugarcane is explored by genetic improvement from hybridizations between parents that presents high yield per si. However, parental recommendation has as a limiting factor the lack of floral synchronism between the genotypes and the lack of characterization of the accessions by the pollen viability, which may reflect on infertility or low fertility of caryopses. Informations about pollen viability of genotypes of sugarcane during the storage time, allow us to estimate the moment when pollen retains its germination power, vigor and genetic integrity to promote hybridizations between parents that have asynchronous flowering. This work aimed to study general aspects from hybridization in sugarcane, verify the existence of correlation between the pollen viability and the fertility of caryopsis, evaluate the viability of the pollen obtained from the upper and lower third of the panicles of tem genotypes, as well as pollen viability during the storage time of four varieties. The experiments were conducted at Estação de Floração e Cruzamento da Cana-de-açúcar de Devaneio. The pollen viability was tested by lugol solution and its conservation was made in a freezer at -18°C. The experimental design was completely randomized in a factorial design. Significant differences were identified among genotypes for all variables analyzed. The conservation method used in this study proved effective for maintaining the viability of three of the four genotypes. It was found a positive correlation between pollen viability and fertility of the caryopsis.