Radiosensitivity and mutability of wheat seed progeny cultivated under adverse environments

Abstract

This research analysed the growth process dynamics of soft wheat (Triticum aestivum L.) seeds cultivated in contrasting microclimatic conditions. We used acute gamma irradiation (5–50 Gy) as a provocative factor to detect hidden differences in the adaptive potential of seeds cultivated under adverse conditions (wet and cool field season) in comparison to seeds obtained under controlled conditions (hydroponic greenhouse). Seeds harvested from wheat plants cultivated in challenging field conditions demonstrated lower weight; moreover, their offspring also had a lower weight and seedling survival rate, as well as a delay in the formation of the fourth – sixth roots. The discrepancy in growth characteristics increased from the beginning to the end of the experiments and was particularly pronounced in offspring cultivated under adverse conditions throughout the entire experiment. The offspring of control seeds were more radioresistant than their field seed counterparts. At the same time, the “field” seeds were characterised by stimulation of growth and development of seedlings in their responses to irradiation. Few seedlings grown from “greenhouse” seeds exhibited evidence of root necrosis and twisted roots. Among the field plants, unusual developmental anomalies for ‘greenhouse’ seeds were encountered, including the disruption of gravitropism, thickening of roots, changes in the form of coleoptiles and leaves, and necrotic coleoptiles. Gamma irradiation stimulated an increase in the number of seedlings with various developmental disorders. In the case of seed progeny grown under adverse conditions, developmental anomalies were more frequent following irradiation relative to optimal conditions.