Development of individual elements of a protocol for sustainable growth and propagation of garden strawberries (Fragaria ananassa Duch.) under aseptic conditions

Abstract

Garden strawberry (Fragaria ananassa Duch.) is one of the most valuable fruits the demand for which in the food market is consistently high. One of the limiting factors for achieving consistently high-quality strawberry yields is the presence of diseases caused by bacteria, phytoplasmas, viruses, and viroids. In order to intensify the technology of garden strawberries cultivation, the problem of production in significant volumes of genetically constant material free from pathogens is essential. Biotechnological methods are currently relevant technologies that allow mass production of planting material with high phytosanitary and genetic quality. The purpose of the study is to update the protocol for microclonal propagation of garden strawberries to obtain virus-free planting material. The research was conducted in the micropropagation laboratory of LLC «Blahodatne» (ТеvittaTM) Cherkasy region, Ukraine using the «Alba» and «Present» strawberry cultivars. A series of experiments were conducted according to the «step by step» principle on two types of explants: buds and meristems. The determinants for obtaining aseptic cultures from bud and meristem explants were investigated. The trophic influence was studied in media with different mineral content (at the multiplication stage) and sucrose concentrations during rhizogenesis. Among the phytohormonal determinants during the multiplication stage, the best combination among those investigated was the use of substances with cytokinin activity consisting of BAP at 0.2 mg/l and kinetin at 0.8 mg/l. The addition of 0.1 ml/l of «Gibb plus preparation» (GK4 + GK7) was effective for the reproduction rate increasing. Growing of donor explants in media with BAP at 0.2 mg/l, kinetin at 0.3 mg/l, and adenine at 0.5 mg/l, compared to the control (BAP at 1.0 mg/l) improved rhizogenesis in regenerants. The highest root formation rates were observed in the variant with 4 % of sucrose (40 g/l). Key words: propagation; microclonal propagation; aseptic culture; trophic and hormonal determination.