871 PB 223 IMPROVED GERMINATION OF PANSY SEED AT HIGH TEMPERATURES BY PRIMING WITH SALT SOLUTIONS

Abstract

Pansy (Viola × wiffrockiana cv. Majestic Giant Blue Shades and Crystal Bowl Sky Blue) seeds were primed in various salt sololions at -1.0 MPa for 3, 6 or 9 days at 23C to determine if priming could overcome thermoinhihition at high temperatures (30C and above). Salt solutions tested were KNO3, KCl, NaCl, MgCl2, Na2SO4, Na2HPO4, K2HPO4 and CaCl2, with polyethylene glycol (PEG) serving as a comparison non-salt solution. Total percent germination (G) of non-primed seeds decreased significantly for both cultivars as germination temperature increased from 25C to 35C. Total seed germination and time to 50% germination (TS,) varied widely among the different priming solutions, with all solutions decreasing Tso as compared to non-primed seeds. Seeds primed with PEG for 6 and 9 days, however, germinated during the priming process and were not further examined. Priming did not significantly improve total percent germination versus non-primed seed at 25C. Seeds that had the best G and T50 at temperatures at or above 30C were those primed for 3 days with CaCl2 (for `Crystal Bowl' there was a 40% increase in G at 35C), and MgCl2 (for `Majestic Giant' there was a 15% increase in G at 35C).