Investigating the Interaction Effects of Temperature, Benzylaminopurine and Antibacterial Compounds on Enzyme Activity and Vase Life of Cut Leaves of Canna indica

Document Type : Full Paper

Authors

• Fatemeh Aghebati ¹
• Vahid Reza Saffari ²
• Homayoun Farahmand ²

¹ Department of Horticultural Science, Shahid Bahonar University of Kerman, Kerman, Iran

² Department of Horticultural Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran

Abstract

Keywords

• Cut foliage
• Essential oil
• Postharvest
• Temperature conditions

Main Subjects

• Ornamental plant science

Extended Abstract

Introduction

Indian shot (Canna indica, Cannaceae) is a rhizomatous bulbous plant with large leaves and prominent veins, whose leaves have a special aesthetic value for flower arrangement. The use of leafy plants is given special attention in the floriculture industry due to their special shape and unique color. Foliage plants include all plants that are generally grown for their branches and leaves, and the flowers are not aesthetically important in this group of ornamental plants. This group includes plants whose leaves are of interest and used as filler leaves. Cut foliages, while having a high economic value, are highly perishable. Postharvest senescence is a limiting factor in the marketability of woody cut species with a wide range of physiological processes. Since the importance of Canna indica and the use of its leaves in flower arrangement as a foliage plant have not been covered so far, this research was performed to improve the postharvest quality of the Indian shot cut leaves using benzylaminopurine and natural essential oils of thyme and savory in different temperature conditions.

Materials and Methods

This research was carried out in the autumn of 2019 in the physiology research laboratory and cold storage of the department of horticulture sciences of Shahid Bahonar University of Kerman. The relative humidity in the laboratory environment was 20-30 % with a temperature of 20 ± 1°C and in the cold storage the humidity was 60-70 % with a temperature of 10 ± 1°C. The leaves of Canna indica were placed in containers containing a preprepared vase solution. The experimental factors used in this research include Benzylaminopurine at three levels (0, 10 and 20 mg/liter), antibacterial compounds at four levels, including Silver nitrate (20 mg/liter), savory and thyme essential oils (50 mg/liter) and control (no consumption), and environmental temperatures at two levels (10°C and 20°C). This study was performed as a CRD-based factorial with four replications and two cut leaves in each replication. In this research, traits such as the activity of enzymes peroxidase, ascorbate peroxidase, polyphenol oxidase, catalase, superoxide dismutase and amounts of hydrogen peroxide, proline, malondialdehyde, along with the appearance quality and vase life of the leaves, were investigated.

Results and Discussion

The results showed that the interaction of ambient temperature, benzylaminopurine and antibacterial compounds on the amount of hydrogen peroxide accumulation, activity of peroxidase enzymes, ascorbate peroxidase, polyphenol oxidase, catalase, superoxide dismutase, proline amount, malondialdehyde content, leaf appearance quality and leaf vase life, was significant at the 0.01 level. With the increase in ambient temperature, the amount of hydrogen peroxide accumulation increased. The amount of malondialdehyde was also significantly increased when using silver nitrate combinational treatment of the of 10°C temperature and 20 mg/liter benzylaminopurine. Also, the longest vase life of the leaves along with maintaining their appearance quality were also observed in this treatment. It seems that lowering the temperature had a significant effect on increasing the leaf quality even at low concentration of benzylaminopurine. While increasing the amount of this cytokinin as an anti-aging regulator at high temperature could not reduce the destructive effects and appearance abnormalities. Decreasing the amount of malondialdehyde as an indicator of membrane stability has increased the vase life. According to the results, temperature increment, increased the enzyme activity in the cut leaves of Indian shot. The increase in enzyme activity is one of the primary defense mechanisms of plants, which improves the vase life of plants by reducing the damage caused by the production of phenols and reactive oxygen species.

Conclusion

The results revealed that the maximum durability and longevity of the leaves for 33 days, while maintaining their quality, occurred in the interaction treatment of 10°C temperature, 10 mg/liter benzylaminopurine and 50 mg/liter essential oil in the cold storage, which was accompanied by lowest amount of hydrogen peroxide accumulation and the lowest content of malondialdehyde. Additionally, an increase in the activity of antioxidant and oxidative enzymes to eliminate and reduce reactive oxygen species was observed in the same treatment.