Topographic tetrazolium testing of Black Walnut (Juglans nigra L.) seeds

Abstract

Summary The aims of this work were (1) to propose a topographic tetrazolium (TZ) test methodology for Juglans nigra seeds by adjusting the wide range of incubation times recommended for Juglans sp., (2) to describe the staining patterns of viable and non-viable seeds, and (3) to establish the relationship between the results of the TZ test and the germination test. Decreasing incubation time from 48 to 4 hours resulted in the best coloration of the seeds. Four staining patterns were observed in viable seeds whereas one pattern accounted for over 95% of the non-viable seeds. Viable seeds which were cold-stratified had a germination of 96%, resulting in a high correlation between the results of the TZ viability test and those from the germination test (r = 0.98) and other indices indicating the rate of germination, namely the germination velocity index (r = 0.89) and the medium time