Submitted to: Seed Technology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2008
Publication Date: 11/1/2008
Citation: Sarath, G., Mitchell, R. 2008. Aged Switchgrass Seed Lot’s Response to Dormancy-breaking Chemicals. Seed Technology Journal 30:7-16. Interpretive Summary: Seed dormancy and germination can control stand establishment in grasses such as switchgrass. This work sought to examine the responses of several switchgrass seed lots to chemicals known to break dormancy in this species. Our data indicate that all chemical treatments were effective, but there were significant differences between the seed lots. Taken together, these results indicate that external chemical treatments could result in better and more uniform seed germination in most seed lots tested and that multiple physiological mechanisms appear to control switchgrass seed germination.
Technical Abstract: This work examined the effects of sodium nitroprusside, potassium ferrocyanide and hydrogen peroxide on the germination of eight lots of after-ripened switchgrass (Panicum virgatum L.) seeds. Seed germination was significantly stimulated by all three chemicals, across all seed lots over the time course of the experiment. However, the responses of individual seed lots to specific chemicals varied considerably. Imbibing seeds on 20 mM peroxide significantly enhanced germination after 2 and 4 days over water controls and the two other treatments. After 6 days, all chemical treatments had significantly enhanced germination over water controls. Coleoptile emergence was significantly improved by chemical treatments as well. Overall, germination on water yielded the lowest number of seeds with coleoptiles. For individual seed lots, germination was stimulated by peroxide in six seed lots, but inhibited in one namely, Lot # 2374. After 6 days post-imbibition, ferrocyanide treatment induced maximal germination in 4 seed lots, peroxide treatment in 3 seed lots and sodium nitroprusside in one seed lot. Taken together, these results indicate that (1) chemicals releasing reactive nitrogen species or peroxide can stimulate seed germination in switchgrass (2) coleoptile emergence and thereby seedling establishment can be influenced by these chemicals and (3) multiple mechanisms appear to control switchgrass seed germination.