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Methods of topographical tetrazolium testing for seed viability of Nitraria tangutorum Bobr. and N. sibirica Pall.

Seed Sci. & Technol 01/2009; 37:691-698.

ABSTRACT Seeds used in this study were collected from N. tangutorum and N. sibirica growing in the desert region of northwest China. The effects of two approaches (embryos allowed to remain in the upper part of cut drupes and embryos that were squeezed out of cut drupes) to expose tissues for staining in tetrazolium solution for evaluation of seed viability were examined by comparing viable seed percentages with actual germination percentages. For embryos remaining in the upper part of the cut drupes treatment, the radicle required 52 h of staining for N. tangutorum, and 48 h for N. sibirica; however, by this time, the staining of the cotyledons was too intense to allow accurate evaluation to viability. For embryos that were squeezed out of cut drupes, the staining of the whole embryos was comparatively uniform, and appropriate for evaluating viability after 12-16 h for N. sibirica, and 16-18 h for N. tangutorum, when stained at 30°C in the dark. The tetrazolium test results for the two seed lots overestimated the actual germination recorded by about 5%. Therefore, staining of extracted embryos is a suitable method for determining viability in these two species.

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