Seed dormancy in six cold desert Brassicaceae species with indehiscent fruits
Seed dormancy in six cold desert Brassicaceae species with indehiscent fruits
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六种寒冷沙漠十字花科果实不开裂物种的种子休眠
DOI：
10.1017/s0960258515000215
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发表时间：
2015-09-01
影响因子：
2.1
通讯作者：
Baskin, Jerry M.
中科院分区：
文献类型：
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作者：
Lu, Juan J.;Zhou, Yuan M.;Baskin, Jerry M.
摘要许多菊科植物的传播单位都是不裂果实，但很少有人研究果皮对种子萌发的影响。本研究旨在探讨中国西北寒漠地区六种菊科植物果皮对种子休眠的影响。在实验室环境条件下，将西伯利亚离子芥、叙利亚欧核菌、光滑Goldbachia laevigata、Spirorrhynchus sabulosus、福海Sterigmostemum fuhaiense和毛果Tauscheria lasiocarpa的完整分散单位和分离种子干燥储存0-12个月，并在5/2、15/2和30/15°C下在光照和黑暗中进行发芽测试。测定了果实和果实内种子吸收的水分量。对于四个物种，完整的果实，孤立的种子和孤立的种子加上去除果皮被用来测试的机械与可能的化学作用的果皮在种子休眠。新鲜分离的种子，具有完全发育的胚，发芽的百分比和速率低于后熟种子。因此，种子具有非深度生理休眠。果皮显着降低发芽，但抑制不是由于缺乏水分吸收的种子或化学抑制剂。6种植物的后萌发种子在果实内萌发率为0-50%。我们的结论是果皮起着主导作用的种子休眠的六个研究物种，它这样做，通过机械限制胚的生长。因此，果皮具有在延长的时间段内传播发芽的潜力。
Abstract The dispersal unit of many species of Brassicaceae is an indehiscent fruit, but relatively few studies have tested the effect of the pericarp on seed germination in this family. Our aim was to determine the effect of the pericarp on seed dormancy in six species of Brassicaceae native to the cold desert of north-west China. Intact dispersal units and isolated seeds of Chorispora sibirica, Euclidium syriacum, Goldbachia laevigata, Spirorrhynchus sabulosus, Sterigmostemum fuhaiense and Tauscheria lasiocarpa were stored dry at ambient laboratory conditions for 0–12 months and tested for germination in light and in dark at 5/2, 15/2 and 30/15°C. The amount of water absorbed by fruits and by seeds within the fruits was determined. For four species, intact fruits, isolated seeds and isolated seeds plus the removed pericarps were used to test for the mechanical versus possible chemical role of the pericarp in seed dormancy. Fresh isolated seeds, which have a fully developed embryo, germinated to lower percentages and rates than afterripened seeds. Thus, seeds have non-deep physiological dormancy. The pericarp significantly reduced germination, but inhibition was not due to lack of water uptake by seeds or to chemical inhibitors. Afterripened seeds of the six species germinated to 0–50% inside the fruits. We conclude that the pericarp plays a dominant role in seed dormancy of the six study species, and it does so by mechanically restricting embryo growth. Thus, the pericarp has the potential to spread germination over an extended period of time.