Post-release fates of seeds in dehiscent and indehiscent siliques of the diaspore heteromorphic species Diptychocarpus strictus (Brassicaceae)
Post-release fates of seeds in dehiscent and indehiscent siliques of the diaspore heteromorphic species Diptychocarpus strictus (Brassicaceae)
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一水硬铝石异形物种 Diptychocarpus strictus（十字花科）的开裂和不开裂长角果种子的释放后命运
DOI：
10.1016/j.ppees.2015.04.001
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发表时间：
2015-01-01
影响因子：
3.6
通讯作者：
Baskin, Carol C.
中科院分区：
文献类型：
--
作者：
Lu, Juan J.;Tan, Dun Y.;Baskin, Carol C.
人们对果实/种子异形植物的形态传播和发芽方面的差异进行了最广泛的研究。然而，异形水硬铝石从种子释放开始到发芽/种子死亡结束的命运已被记录在相对较少的物种中。我们的主要目标是在几年内或直到它们发芽或死亡之前追踪 Diptychocarpus strictus 的两种传播单位形态的命运。我们的假设是，来自开裂的上部长角果的有翅、粘液种子（传播单元）形成了一个短寿命的种子库，而位于不裂的下部长角果（传播单元）内的几乎无翅、非粘液的种子则形成了一个长寿的种子库。因此，对于这两个变种，我们监测了2010年种子释放的物候、2010年至2014年的发芽物候以及2010年至2012年土壤埋藏期间的发芽和存活。所有下部长角果均已在7月下旬从母株中释放出来，而上部长角果的带翅种子的种子释放直到10月下旬才完成，此时主茎已脱离（靠近基地）。大多数来自上部长角果的种子（约 20%）在 2011 年春季发芽，而下部角果中的种子直到 2011 年秋季才发芽（0.2%）。到 2012 年秋季发芽季节结束时，来自上部长角果的所有种子均已发芽或失去活力，而下部角果内的 11% 种子于 2014 年秋季发芽，并且很大比例的未发芽种子仍然具有活力，从而支持了我们的假设。两种变体的埋藏种子均表现出 6 个月的休眠周期，其中非休眠期与两个发芽季节一致。上角果开裂和下角果不开裂是D. strictus具有高风险-低风险策略(H/H-L/L)的水硬铝石扩散和休眠所必需的。 (C) 2015 年，ETH 地球植物研究所，鲁贝尔基金会。由爱思唯尔有限公司出版。版权所有。
Fruit/seed heteromorphic plants have been studied most extensively for differences in dispersal and germination of the morphs. However, fates of the heteromorphic diaspores beginning with seed release and ending with germination/seed death have been documented for relatively few species. Our primary aim was to follow the fates of the two dispersal unit morphs of Diptychocarpus strictus over a several-year period or until they germinated or died. Our hypothesis was that the winged, mucilaginous seeds (dispersal unit) from the dehiscent upper siliques form a short-lived seed bank and the nearly-wingless, nonmucilaginous seeds inside the indehiscent lower siliques (dispersal unit) a long-lived seed bank. Thus, for the two morphs we monitored phenology of seed release in 2010, germination phenology from 2010 to 2014 and germination and survival during burial in soil from 2010 to 2012. All lower siliques had been released from mother plants by late July, whereas seed release of the winged seeds of upper siliques was not completed until late October, after the main stem had become detached (near the base). Most seeds (18%) from upper siliques that did so (c. 20%) germinated in spring 2011, whereas no seeds in lower siliques germinated until autumn 2011 (0.2%). All seeds from upper siliques had germinated or lost viability by the end of the autumn 2012 germination season, whereas 11% of seeds inside lower siliques germinated in autumn 2014 and a high proportion of the nongerminated seeds was still viable, thus supporting our hypothesis. Buried seeds of both morphs exhibited a 6-mo dormancy cycle in which the nondormant phase coincided with the two germination seasons. Dehiscence of the upper siliques and indehiscence of the lower siliques are required for D. strictus to have a high risk-low risk strategy (H/H-L/L) for diaspore dispersal and dormancy. (C) 2015 Geobotanisches Institut ETH, Stiftung Ruebel. Published by Elsevier GmbH. All rights reserved.