Effects of origin, seasons and storage under different temperatures on germination of Senecio vulgaris (Asteraceae) seeds.
Effects of origin, seasons and storage under different temperatures on germination of Senecio vulgaris (Asteraceae) seeds.
复制标题
产地、季节及不同温度贮藏对菊科千里光种子萌发的影响
作者：
Ndihokubwayo N;Nguyen VT;Cheng D
入侵植物占领新环境，成为害虫，造成生物多样性丧失、经济损失和健康损害。禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科禾本科。本研究通过对寻常花（S. vulgaris）萌发行为的研究来解释其在中国的分布及其生物入侵。以6个本土种群和6个外来种群的种子为研究对象，分别在气候室和室外条件下进行了萌发实验。在气候室（15°C）中培养时，大多数种群的种子萌发率（GP）为50 ~ 90%，原生和入侵种子的萌发率相等。不同群体间的平均发芽时间差异显著。在室外条件下，产地、储存条件（4°C或环境室温，约27°C）和季节（夏季或秋季）对GP有显著影响，而MGT仅受季节影响。秋季GP（38.6%）高于夏季，MGT略长；秋季，4℃贮藏种子的GP值高于室温贮藏种子（约27℃），入侵种群种子的GP值高于本地种群。研究结果表明，夏季高温对山楂种子萌发有不利影响，可能导致山楂种子活力丧失或二次休眠。本研究通过解释为什么在中国东南部和中部城市，如武汉，寻常花不能建立自然和可生存的种群，为探索限制寻常花在中国分布的因素提供了线索。
Invasive plants colonize new environments, become pests and cause biodiversity loss, economic loss and health damage. Senecio vulgaris L. (Common groundsel, Asteraceae), a widely distributing cosmopolitan weed in the temperate area, is reported with large populations in the north–eastern and south–western part, but not in southern, central, or north-western parts of China. We studied the germination behavior of S. vulgaris to explain the distribution and the biological invasion of this species in China. We used seeds originating from six native and six invasive populations to conduct germination experiments in a climate chamber and under outdoor condition. When incubated in a climate chamber (15 °C), seeds from the majority of the populations showed >90% germination percentage (GP) and the GP was equal for seeds with a native and invasive origin. The mean germination time (MGT) was significantly different among the populations. Under outdoor conditions, significant effects of origin, storage conditions (stored at 4 °C or ambient room temperature, ca. 27 °C) and seasons (in summer or autumn) were observed on the GP while the MGT was only affected by the season. In autumn, the GP (38.6%) was higher and the MGT was slightly longer than that in summer. In autumn, seeds stored at 4 °C showed higher GP than those stored at ambient room temperature (ca.27 °C), and seeds from invasive populations revealed higher GP than those from native populations. The results implied that the high temperature in summer has a negative impact on the germination and might cause viability loss or secondary dormancy to S. vulgaris seeds. Our study offers a clue to exploring what factor limits the distribution of S. vulgaris in China by explaining why, in the cities in South-East China and central China such as Wuhan, S. vulgaris cannot establish natural and viable populations.