Abstract:

A large proportion of up to 90% of the seeds of Codariocalyx motorius are hard seeds of varying degrees as revealed during the process of imbibition. The seeds that were able to imbibe on the first day had the lowest degree of hardness and were regarded as non-hard,while the seeds that took increasingly more time to imbibe had increasingly higher degrees of hardness. The seeds that remained unimbibed on the fifth day were taken as the hardest seeds for the test in this study,which were shown,after their dormancy being broken by 80～90 ℃ hot water treatment,to have higher germination rate,vigour index and stress resistance,and lower electric conductivity,in comparison to those of the control. The results indicate that the hard seeds have higher seed vigour than the non-hard seeds in seed lots of Codariocalyx motorius,and that the seed vigour increases with the degree of seed hardness. For this reason,the hard seeds are of better quality in seed lots of Codariocalyx motorius.

Key words: Codariocalyx motorius, hard seed, degree of seed hardness, germination percentage, seed vigour