Time-dependent changes of the physiological status ofBromus inermisLeyss. seeds from chronic low-level radiation exposure areas

Abstract

The seed progeny of smooth brome (Bromus inermis Leyss.) were evaluated over a year for their viability, mutation rate, resistance to radiation and antioxidant status in response to chronic radiation exposure. Bromus inermis is found in the Eastern Ural Radioactive Trace (EURT) area and the background territories (surrounding territories that are used as controls as they only have natural background radiation). The absorbed doses by smooth brome from the EURT area were 1.5-18.5 times higher compared to background locations for parent plants and 1.1-11.6 times higher for the seed embryos. There are predictable and asynchronous changes in the survival of shoots and root growth rate between background populations and chronically irradiated samples. The provocative dose of 250 Gy is more damaging in the winter months, than in the summer and autumn. The frequency of anomalies in shoots varied in different months, with the biggest rate of mutation recorded in physiologically harsher period (autumn-winter). There is no correlation between resulting survival rate of shoots and their resistance to radiation. The intense activity of the antioxidant systems (estimated by the content of low molecular weight antioxidants) allowed faster growth of the shoots and reduced the number of abnormalities seen in development.

Influence of Nitrogen and Phosphorus Fertilization on Quality and Germination Potential of Smooth Bromegrass Seed

“…is a kind of perennial and rhizomatous grass with high forage value and productivity (Liu et al, 2014). It is characterized by a high tolerance to drought and low temperatures and a medium resistance to soil salinity, this species has already been introduced for restoring degraded grassland and establishment of artificial pasture (Liu et al, 2008;Antonova et al, 2015). Breeding of smooth bromegrass has focused on increasing biomass and seed yield (Wang et al, 2012).…”