Seasonal dormancy patterns and stratification requirements in seeds of Verbena officinalis L.
Seasonal dormancy patterns and stratification requirements in seeds of Verbena officinalis L.
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DOI：
10.1078/1439-1791-00164
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发表时间：
2003-01-01
影响因子：
3.8
通讯作者：
Schütz, W
中科院分区：
文献类型：
--
作者：
Brändel, M;Schütz, W
对马鞭草(马鞭草科)的休眠模式和萌发响应进行了研究。马鞭草是一种分布广泛的杂草，但被认为是一种原产地中海的植物。在最初的实验中，埋在田里的种子样本被每月挖出一次，历时38个月，并在25/15摄氏度和1515摄氏度的光照和黑暗中测试发芽情况。种子在新鲜成熟时休眠强烈，越冬时解除休眠。种子在春季进入条件休眠，而休眠解除主要发生在冬季。没有种子死亡，在埋葬过程中土壤中也没有萌发。结果表明，药用植物在晚春萌发较好，具有积累持久种子库的潜力。第二次实验研究了层积温度和时间对休眠的影响。干燥储存的种子在黑暗中3-18摄氏度的温度范围内分层潮湿，持续时间长达28周，并在一定范围的恒温(3-25摄氏度)和1515摄氏度的光照下以及25摄氏度和1515摄氏度的黑暗中进行测试。种子在3-12摄氏度的温度下休眠解除，较高的温度对解除休眠无效。在28周的层积期间，没有诱导二次休眠。我们的结论是，休眠诱导需要逐渐提高环境温度和/或增加幅度大小。弱休眠的种子需要较高的恒定平均值(>；15℃)或波动的温度才能萌发。只有一小部分种子获得了在黑暗中通过递增层积发芽的能力。没有迹象表明萌发和休眠特征可以被解释为对地中海条件的残余适应。
Dormancy patterns and germination responses to incremental stratification were investigated in Verbena officinalis L. (Verbenaceae), a widely-distributed ruderal, but considered as an originally mediterranean plant. In an initial experiment, samples of seeds buried in the field were exhumed at monthly intervals over a period of 38 months and tested for germination in light and darkness at 25/15 degreesC and 1515 degreesC. Seeds were strongly dormant when fresh and mature and came out of dormancy during winter. Seeds entered conditional dormancy in spring, while main dormancy relief occurred in winter. There was no seed mortality, and no germination occurred in the soil during burial. The results imply, that V officinalis germinates preferably in late spring and has the potential to accumulate a persistent seed bank.The effects of stratification temperature and duration on dormancy were investigated in a second experiment. Dry-stored seeds were stratified wet at a range of temperatures from 3-18 degreesC in darkness for periods of up to 28 weeks, and tested over a range of constant temperatures (3-25 degreesC) and at 1515 degreesC in light, and at 25 degreesC and 1515 degreesC in the dark. Seeds came out of primary dormancy when kept at temperatures between 3-12 degreesC, while higher temperatures were ineffective in breaking dormancy. There was no induction of secondary dormancy during the stratification period of 28 weeks. We conclude that a gradual increase of the ambient temperatures and/or an increase in amplitude size is required for dormancy induction. Weakly dormant seeds required either high constant mean (> 15 degreesC), or fluctuating temperatures for germination. Only a small fraction of the seeds acquired the ability to germinate in darkness with incremental stratification. There is no indication of germination and dormancy traits that can be interpreted as relict adaptations to mediterranean conditions.