Effects of origin, seasons and storage under different temperatures on germination ofSenecio vulgaris(Asteraceae) seeds

Abstract

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.

Diversity analysis of the rhizospheric and endophytic bacterial communities of Senecio vulgaris L. (Asteraceae) in an invasive range

“…It can produce large numbers of seeds, which can germinate under the right conditions at any time; therefore, its ability to spread is very high (Robinson et al, 2003). This species was introduced into northeast China in the 19th century, and it is now widely distributed across China and is included in The Checklist of the Invasive Plants in China (Ndihokubwayo, Nguyen & Cheng, 2016; Zhu et al, 2016; Cheng et al, 2017). Senecio vulgaris grows well in ambient habitats, such as gardens, lawns, and arable land, and also survives in stressful habitats such as roadside areas and waste facilities (Robinson et al, 2003).…”

Non-deep physiological dormancy and germination characteristics of Primula florindae (Primulaceae), a rare alpine plant in the Hengduan Mountains of southwest China

“…Seed dormancy is a very common phenomenon in arctic-alpine plant species, and more than 70% of them produce primary dormant seeds, exhibiting mainly physiological dormancy (PD) ( Baskin & Baskin, 2014 ; Schwienbacher et al, 2011 ). Its production can prevent seed germination during cold autumn/winter seasons and also be seen as an environment that is not long enough to support seedling growth ( Ndihokubwayo, Thang & Cheng, 2016 ). Seeds with PD have fully developed embryos that have a physiological inhibiting mechanism (high abscisic acid (ABA)/gibberellic acid (GA) ratio) in the freshly shed seeds ( Baskin & Baskin, 2014 ), which prevents germination at any temperature or allows it only at high temperatures (conditional dormancy).…”

Seed longevity, viability and germination of four weed-ruderal Asteraceae species of ethnobotanic value

“…& A. Gray which seeds reduced germination with aging and at room temperatures of 25-27 o C (Walck et al 1997, Gomes & Fernandes 2002, Ndihokubwayo et al 2016. Knowledge of seed traits allows us to determine appropriate storage conditions, since, if seeds are viable and long-lived but do not germinate, they may have dormancy, which could make them susceptible to prolonged storage.…”