Reduced Sensitivity of <i>Campomanesia adamantium</i> (Cambess.) O. Berg Seeds to Desiccation: Effects of Polyethylene Glycol and Abscisic Acid

Abstract

The Campomanesia adamantium is a threatened species from Brazil Savannah wh ich seeds are desiccation - sensitive and do not withstand storage. This study aimed to reduce the sensitivity of Campomanesia adamantium seeds to desic cation using polyethylene glycol (PEG) and abscisic acid (ABA). Initially, seeds were subjected to PEG (0, -1.48, and -2.04 MPa) with or without ABA (100 μM) during 120 h, followed fast drying (silica gel) or slow drying (laboratory environment), at 20%, 15%, and 10% moisture content. In the second experiment, the seeds were PEG treated (-1.48 MPa) which provided the best results in the first experiment; the seeds were then subjected to different incubation times in PEG (30, 60, 90, or 120 h) and ABA (0, 10 ˉ 3 , 10 ˉ 4 , and 10 ˉ 5 μM) , following the seeds were fast dried at 15% moisture content. The slow drying should be avoided, even in seeds previously subjected to osmotic conditioning with or without ABA. Seeds submitted to PEG treatment (-1.48 MPa/120h) without ABA and PEG (-1.48 MPa) with 10 ˉ 3 or 10 ˉ 4 μM of ABA (90 h), followed by fast drying at 15% moisture content showed reduction of desiccation sensitivity and high germination and vigor when compared to the other treatments.