Both anti-oxidation and lipid-carbohydrate conversion enhancements are involved in priming-improved emergence of Echinacea purpurea seeds that differ in size
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- 作者：K.Y. Chiu ; S.J. Chuang and J.M. Sung
- 关键词：Antioxidative activity ; Echinacea purpurea ; Glyoxylate cycle ; Purple coneflower ; Seed quality ; Seed priming
- 刊名：Scientia Horticulturae
- 出版年：2006
- 出版时间：10 April 2006
- 年：2006
- 卷：108
- 期：2
- 页码：220-226
- 全文大小：156 K
文摘
This study evaluated the effects of priming on emergence responses of purple coneflower (Echinacea purpurea L. Moench) seeds. The seeds that differ in seed size were either primed with moistened vermiculite (solid matrix priming) or primed in non-aerated −0.5 MPa polyethylene glycol 6000 solution at 25 °C for 6 days (osmopriming), followed by air-drying to their initial moisture level. The tetrazolium staining tests indicated that both large and small seeds were biochemically viable. No notable difference in germination percentage was found between large and small seeds. However, extensive cavity was visible in portions of small seeds in comparison with large seeds. Large seeds accumulated more antioxidants and had greater activities of anti-oxidative enzymes than small seeds. They also had greater isocitrate lyase and malate synthase activities than small seeds. As a result, large seeds had higher emergence percentage and faster emergence speed as compared to that of small seeds. Both solid matrix priming and osmopriming increased emergence percentage and shortened mean emergence time of purple coneflower seeds by increasing the activities of anti-oxidative enzymes and decreasing the levels of malondialdehyde and total peroxide accumulation. Moreover, priming also enhanced the anti-oxidative activities of treated seeds. The activities of isocitrate lyase and malate synthase were also increased in primed seeds. The enhanced anti-oxidation and lipid-carbohydrate conversion activities might explain in part why primed purple coneflower seeds emerged better than non-primed seeds.