Abstract:

[Objective] The aims of the present study were to assess the effects of delinting with sodium hydroxide （NaOH） solution on seed vigor of Bothriochloa ischaemum （B. ischaemum）, and to provide convenient conditions for its mechanized sowing. [Method] B. ischaemum seeds were delinted with NaOH solution with concentrations of 10%, 20%, 30%, 40% and 50% （W/V） for 0 （CK）, 1, 5, 10 and 15 min, respectively. The germination percentage （Gp）, germination index（Gi）, mean germination time （MGT） and seedlings vigor index （SVI） were analyzed to determine the best condition for delinting of B. ischaemum seeds. [Result] NaOH solution concentrations and treatment time had extremely significant （P<0.01） effects on B. ischaemum seed vigor. Within the same treatment time, Gp and Gi of B. ischaemum seeds elevated with the increase of NaOH solution concentrations after delinting for 1-10 min; SVI of B. ischaemum seeds improved with the increase of NaOH solution concentrations after delinting for 1 and 10 min, and decreased first and then rose with the increase of NaOH solution concentrations after delinting for 5 min; the Gp, Gi and SVI boosted first and then declined with the increase of NaOH solution concentrations after delinting for 15 min. At the concentrations of 20%-50% of NaOH solution, the Gp, Gi and SVI ascended first and then reduced with the extension of treatment time after delinting. The MGT of B. ischaemum seeds delinted with NaOH solution was all higher than that of CK. [Conclusion] Soaking with appropriate concentrations of NaOH solution effectively removes the surface hair of B. ischaemum seeds and improves their vigor. Delinting with NaOH solution at the concentration of 50% for 5 min has the best effect on promoting the vigor of B. ischaemum seeds.

Key words: sodium hydroxide solution, Bothriochloa ischaemum, seed vigor, seed delinting