Effects of soil contamination by trace elements on white poplar progeny: seed germination and seedling vigour

Abstract

Seed germination is considered a critical phase in plant development and relatively sensitive to heavy metals. White poplar (Populus alba) trees tend to accumulate Cd and Zn in their tissues. We tested if soil contamination can affect P. alba progeny, reduced seed germination and explored the distribution of mineral elements in the seed. For this purpose, fruits and seeds from female P. alba trees were selected from two contaminated and one non-contaminated areas. Seeds from all the sites were germinated using only water or a nutritive solution (in vitro). Concentrations of nutrients and trace elements in the fruits and seeds were analysed. Seedling growth in vitro was also analysed. Finally, a mapping of different elements within the poplar seed was obtained by particle-induced X-ray emission (PIXE). Germination was similar between different progenies, refuting our hypothesis that seeds from a contaminated origin would have reduced germination capacity compared to those from a non-contaminated site. Seedling growth was not affected by the contaminated origin. Cadmium and Zn concentrations in fruits produced by P. alba trees in the contaminated sites were higher than by those from the non-contaminated site. However, the nutritional status of the trees was adequate in both cases. Cd in seedlings was higher in those from contaminated soils although lower than in fruits, indicating a certain exclusion from seeds. Preliminary results of the PIXE technique showed that Al and Zn were distributed uniformly in the seeds (Cd was not detected with this technique), while the nutrients P and S were concentrated in the cotyledons.

Assessment of heavy metal bioaccumulation in sorghum from neutral saline soils in the Po River Delta Plain (Northern Italy)

“…Zinc and copper are essential elements for humans and among the micro-metallic elements they are normally the most abundant in plants (Singh et al 2010;Bini et al 2013;Grembecka and Szefer 2013;Zhang et al 2014;Madejón et al 2015;Pirsaheb et al 2016). Measured concentration of Zn and Cu in seeds (40 and 7.4 mg*kg -1 respectively) are in agreement with the data obtained by Bianchini et al (2012) on cereals grown in the same area (Fig.…”

Germination and initial development of Brachiaria brizantha and Brachiaria decumbens on exposure to cadmium, lead and copper

“…As with the data obtained here, Saderi and Zarinkamar (2012) have obtained germination reductions and low root growth of Matricaria chamomilla exposed to Cd and Pb. In seeds of Populus alba contaminated by Cd, Madejón et al (2015) have not found differences in vigor of these seeds comparing with non-contaminated seeds. It is worth noting that the contamination tested by these authors was in seeds and not in the environment.…”

“…Germination is the most sensitive phase in a plant life cycle and there is no consistent test or measurable parameter valid for all possible conditions at the time of sowing, i.e., in vitro germination does not refer to the plants field development conditions (Madejón et al, 2015). Germination tests serve as a preliminary parameter to seedlings development in exposure to trace elements (Di Salvatore et al, 2008).…”

Cu Immobilization and Lolium perenne Development in an Acid Vineyard Soil Amended with Crushed Mussel Shell

“…According to these authors, seed germination is lower under low and high pH values than under intermediate pH values. Regarding the possible Cu effects on seed germination, different authors showed that it was very low (Madejón et al ., ; Verdejo et al ., ; Caetano et al ., ). The general trend found in seed germination in response to CMS additions may be related with the soil pH behaviour.…”