Tetrazolium test to evaluate viability and vigour in Genipa americana seeds

Abstract

Evaluating the vigour and viability of seeds can help in the production of seed lots with proven high physiological potential. In this regard, the tetrazolium (TZ) test is efficient, rapid and inexpensive; however, it not been fully explored for forest species. Further development of species-specific methodologies is required in order to maximise the test efficacy. The objective of this work was to define a tetrazolium test protocol to evaluate the vigour and viability of Genipa americana L seeds. Fruits and seeds were characterised for biometry and initial water content before and after hydration. Germination, germination speed index, electrical conductivity and seedling emergence was also performed. For the TZ test, G. americana seeds were cut longitudinally and submitted to different seed pre-conditioning methods (with and without 24 hours imbibition), different TZ concentrations (0.05, 0.075, 0.10 and 0.25%) and three immersion periods (2, 3 and 4 hours). The tetrazolium test allowed adequate evaluation of seed vigour levels (Viable; Viable and non-vigourous; and Non-viable). Immersion of non-imbibed seeds in 0.10% TZ solution, for three hours is the most efficient protocol for evaluating the vigour and viability of G. americana seeds.