Seed vigour evaluation in petunia seed lots to predict seedling emergence and longevity

Abstract

This study examined the potential of different vigour tests to reveal differences in performance of nine hybrid petunia seed lots. Saturated salt accelerated ageing test (SSAA) and 48-hour radicle emergence (RE48h) tests were able to predict seedling emergence and longevity potential. The results of accelerated ageing (AA) (at 41/43°C, 48/72 hours, 100% RH), saturated salt accelerated ageing (SSAA) (at 41/43/45°C, 72 hours, 75% RH), mean germination time (MGT), 48-hour radicle emergence (RE48h) and electrical conductivity (EC) tests were compared with seedling emergence in modules and longevity (at 5°C for 24 months and 25°C for 12 months). Initial standard germination (SG) percentages were above 83% in the lots. Seedling emergence ranged between 18 and 89%, germination after storage was between 16 and 88% at 5°C, and 13 and 96% at 25°C. The SSAA test at 43°C and 45°C for 72 hours was correlated with both seedling emergence and longevity. RE48h was correlated with emergence and germination after storage at 5°C for 24 months; MGT and SG was correlated with seedling emergence. Neither AA nor the EC test was correlated with emergence and longevity. Thus vigour, expressed as both emergence and storage potential, was successfully predicted by the SSAA test and RE48h.