Desenvolvimento in vitro de embriões imaturos oriundos de tangerineira 'poncã' x laranjeira 'pera' em diferentes fotoperíodos

Abstract

It was aimed to study the influence of the photoperiod on in vitro culture of immature embryos from Poncã mandarin and Pera sweet orange fruits. The embryos were removed from 30–40-mm wide fruits and inoculated on the MS medium, supplemented with 0.3 mg L-1 GA3 and 1 mg L-1 activated charcoal, previously sterilized at 121°C for 20 minutes. The following photoperiods were evaluated: 8, 10, 12, 14, 16, 18, and 24 hours of continuous light in 43 µM.m-2.s-1 intensity, at 27ºC, in B.O.D chambers. The 16 hours continuous light was performed in growth room at 35 µM m-2 s-1. The statistical analysis used was entirely randomized, with four replications, each one constituted of three tubes. After 60 days, better results for plant height, number of leaves, above ground fresh matter weight, root length, and root fresh weight were obtained with 8, 10, 12, 14, 18 e 24 hours photoperiod. The 16 hours rendered smaller immature embryos development.