Determinação de meio de cultura e aplicação de ácido bórico em botões florais na germinação de grãos de pólen de nespereiras

Abstract

This study aimed to establish a culture media and evaluate pollen grains germination in vitro and after boron applying in the panicles of Loquat cultivars. Was established an appropriate culture media for pollen grains germination and evaluated the germination percentage in Mizauto cultivar. Was also evaluated the best stage of floral growth and the best period of the day to collect the pollen, beyond the evaluation of incubation time for their germination. After established the appropriate culture media, it was determined the germination of 9 cultivars: Mizauto, Mizuho, Fukuhara, Parmogi, Centenária, Kurisaki, Néctar de Cristal, Mizumo and Precoce de Campinas. On the field, was evaluated the applying of boric acid with different concentrations 600, 1200 and 1800 mg.L -1 and without applying on the panicles of Mizauto cultivar. The culture media established was composed by 200 g. L ‑1 of sucrose, 1200 mg.L ‑1 of boric acid, solidified with 10 g.L ‑1 of Agar and pH 6, and incubated during seven hours. The best stage of floral bud was in pre-anthesis, collected between two and six pm. The applying of 900 mg.L ‑1 of boric acid on field raised the pollen grain germination to 57.68%.