Storage life for seeds of perennial grasses for breeding nurseries

Abstract

Background. In the breeding of perennial grasses, the availability of a sufficient amount of seed material is of great importance, therefore, there remains a need to maintain a safety reserve of the seeds obtained and monitor their seeding quality. Studying changes in the laboratory seed germination during storage makes it possible to define the maximum period of their use. Materials and methods. The study employed 140 seed samples of awnless bromegrass (Bromopsis inermis (Leyss.) Holub), 300 of red clover (Trifolium pratense L.), and 88 of changeable alfalfa (Medicago varia Martyn), grown in Tyumen Province in 2008–2018. Seeds were permanently stored in a laboratory at a room temperature of 18–22 °С. Laboratory seed germination was assessed according to GOST 12038-84 annually from February to April for six years (2017–2022). The obtained seed germination rates were grouped according to the seed storage duration. Results and conclusions. A majority of awnless bromegrass and red clover seed samples, stored without applying any special conditions, remained viable in terms of their germination (at least 80 %) for 1.5 years after harvesting, and those of changeable alfalfa up to 5.5 years. Variations in seed germination rates among the seeds obtained in different years and those harvested within the same year changed with an increase of the storage period duration (V = 3.6–29.8 %), which attested to a greater heterogeneity of the material under study and could be caused by the presence and development of pathogenic microflora on seeds. Promising seed samples for breeding or for storage, with laboratory germination rates from 79 to 50 %, can be sown with an increased seeding rate on certain plots; meanwhile, the estimated maximum practical use for the seeds of awnless bromegrass is up to 3.5 years; for red clover up to 5.5 years; and for changeable alfalfa up to 8.5 years.