Effect of collection time on the viability of banana pollen grains

Abstract

The objective of this study was to assess the pollen viability of six improved diploid banana plants (AA) collected in different periods of the day, in two seasons of the year (winter and summer), using in vitro germination test and staining. Pollen grains collected at 8 am (anthesis), 10 am, 12 pm, 2 pm and 4 pm were evaluated. We used a culture medium for pollen germination containing 15% sucrose, 0.01% H 3 BO 3 , 0.01% KNO 3 , 0.03% Ca(NO 3) 2 .4H 2 O, and 0.02% MgSO 4 .7H 2 O, solidified with 0.8% agar, adjusted to different pH. The pollen viability was evaluated by staining with 2,3,5-triphenyltetrazolium chloride (TTC). The highest pollen germination rates and viability were obtained at 8 am and the lowest at 4 pm, in both seasons. The average in vitro germination percentage and viability level were negatively influenced by the number of hours after anthesis. During the summer, the pollen viability and in vitro germination rates were highest when compared to winter period. The results presented can help at the selection of genetic materials and enable inferences on the best pollen collection time for use in cross breeding programs for plant improvement.