Growth and Flower Bud Induction in Strawberry ‘Sulhyang’ Runner Plant as Affected by Exogenous Application of Benzyladenine, Gibberellic Acid, and Salicylic Acid

Abstract

Strawberry (Fragaria × ananassa) is one of the most important and popular fruit crops in the world, and ‘Sulhyang’ is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid (GA3), and salicylic acid (SA) on growth and flower bud induction in strawberry ‘Sulhyang’ was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with 25oC/15oC (day/night) temperatures, 70% relative humidity (RH), and light intensity of 300 μmol·m-2·s-1 photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and 200 mg·L-1 of BA, GA3, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with GA3. However, the treatment of 200 mg·L-1 GA3 promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of 200 mg·L-1 SA, followed by 100 mg·L-1 SA. Overall, results suggest that foliar application of GA3 solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between GA3 and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.