Effects of Some Bacterial Isolates on Vase Life of Cut Rose Flowers

To reduce the impact of rapid temperature changes during transportation on cut flowers, continuous cooling should be provided throughout the process. The frigid transportation conditions required to transport cut flowers from their production facilities to the point where they will be marketed are quite expensive. Preliminary applications that can significantly reduce this cost should be made. One of these applications is the use of symbiotic psychrotolerant bacteria, which thrive at low temperatures, to improve the transportation and shelf life of cut flowers. Cut roses are commercially transported and stored at +2-4°C. In this study, the application of psychrotolerant bacteria isolated from plants aims to investigate their effects on the transportation and vase life of cut roses under unfavorable transport temperature conditions (+10 °C), aiming to minimize potential quality losses. For this objective, 18 bacterial strains were isolated from the leaf apoplasts of cold-resistant wild plants. These strains, which exhibit cold tolerance and the ability to block ethylene synthesis in plants, were used both separately and in combination. Bacterial solutions were applied to cut rose leaves (Rosa hybrida L. cv. Samourai), and all treatment groups were kept in controlled conditions at +10°C for 9 days. Control 1 and Control 2 were treatments in which only pure water was sprayed on the green leaves of cut roses at temperatures of +2 oC and +10 oC, respectively. At the end of the experiment, the cut roses were evaluated according to vase life, fresh weight, visual quality, and cold damage (CD). The longest vase life was determined in D3 (DT-10 isolate-Bacillus cereus), D4 (DT-11 isolate- Bacillus cereus), M1 (DT-17 isolate-P. proteolytica) and K1+B8 (Bacillus cereus + S. kitahiroshimense) applications. These applications, which have obtained the highest vase lifetimes, and B5, B8, D1, D2, K3, Ç1, Ç2, M2, and D1 + Ç1 applications were in the same statistical group. The D3, D4, M1, and K1+B8 treatments increased the vase life of cut roses by 55.55% compared to Control 2. Control 1 and D1+Ç1 treatments showed the highest relative fresh weight increase in 66.06% and 64.28%, respectively. Among the groups, the D2 (DT-6 isolate-Bacillus cereus) had the greatest visual quality score. The lowest CD% was observed in the application involving the D2 isolate, correlating with the highest visual quality determined under the same D2 application. The study revealed that postharvest application of Bacillus cereus isolates (especially DT-6 and DT-10) to cut roses increased their vase life.