红砂(Reaumuria soongarica)种子萌发特性及其局部适应性
收稿日期: 2015-12-06
修回日期: 2016-02-24
网络出版日期: 2016-05-20
基金资助
中国科学院"百人计划"项目(29Y127E71);国家自然科学基金项目(31370395,31500266)
Seed Germination Characteristics and Local Adaptation of Reaumuria soongarica
Received date: 2015-12-06
Revised date: 2016-02-24
Online published: 2016-05-20
种子萌发特性是荒漠植物适应干旱的重要策略。红砂(Reaumuria soongarica)是典型耐旱植物,但目前缺乏从群体角度探讨其种子萌发特性和其局部适应性关系的报导。在25、4、-20、-40 ℃下,分别对来自于甘肃、宁夏和新疆的17个地区红砂种子进行发芽试验,检测不同群体在萌发时间、萌发率和发芽势上的差异,并用world-clim的气象数据分别对不同群体的萌发率和发芽势进行了相关性分析。结果表明:低温贮藏会削弱红砂种子的休眠、缩短红砂种子的初始萌发时间和萌发持续时间。经不同温度贮藏,红砂种子萌发率的变化不显著,其变化主要来自于不同群体间的差异,而且萌发率与其生存环境的温度和降水量显著相关。红砂种子的发芽势在-40 ℃温度贮藏后显著提升,呈现爆发型萌发,说明超低温储藏能极大消除红砂种子的生理休眠。此外,红砂种子的发芽势和环境温度显著相关。红砂种子的萌发特性表现出其对干旱生境的局部适应性,这一结果有助于深入理解荒漠植物对干旱环境的生态适应性机理,并为红砂在荒漠植被恢复中的推广提供理论和数据支撑。
石勇 , 刘源 , 殷恒霞 , 燕霞 , 马小飞 . 红砂(Reaumuria soongarica)种子萌发特性及其局部适应性[J]. 中国沙漠, 2016 , 36(3) : 644 -650 . DOI: 10.7522/j.issn.1000-694X.2016.00013
Seed germination is critical for desert plants to adapt to drought, especially for Reaumuria soongarica, a constructive shrub species in temperate desert ecosystems. However, the relationship between seed germination and local adaptation from the perspective of populations are far from clear. R. soongarica seeds were sampled from 17 geographical regions in Gansu, Ningxia or Xinjiang Provinces and stored at 4 ℃, 25 ℃, -20 ℃ or -40 ℃. Then germination were performed to fully investigated the variations on germination time, germination rate and germination energy. Moreover, correlation analyses were performed to assess the association between the world-clim data and germination rates or germination energy. The results showed that low temperature storage can weaken R. soongarica's seed dormancy and shorten the time to initial seed germination and the time for germination duration. Germination rate is not affected by storage temperature, but varies among populations of R. soongarica. Seed germination rates of different populations were significantly associated with temperature and precipitation of their original habitat. After storage at -40 ℃, R. soongarica's germination energy from all the populations significantly improved as an explosive way, suggesting that the physiological dormancy of the seeds of R. soongarica can be eliminated by the super low temperature storage. And the differentiation of germination energy among populations was significantly correlated with temperature of their original habitats. These seed germination characteristics of R. soongarica strongly suggested they adapted locally to the heterogeneity conditions of diverse ecosystems. Our study sheds light on better understanding of ecological basis of desert plants to adapt to desert environments, and provides an empirical and theoretical supports for promoting R. soongarica in the restoration engineer of desert ecosystems.
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