Adenine type and diphenyl urea derived cytokinins improve the postharvest performance of Iris germanica L. cut scapes

Abstract

An experiment was designed to evaluate the effect of various adenine derived cytokinins (kinetin and 6-benzylaminopurine) and diphenyl urea cytokinin (thidiazuron) on the postharvest performance of cut scapes of Iris germanica. Flower scapes were harvested with the oldest bud at '1 day before anthesis stage', brought to laboratory under water, cut to a uniform length of 35 cm, divided into three sets viz., kinetin (KIN), 6-benzyl aminopurine (BAP) and thidiazuron (TDZ). Each set of scapes was treated with a particular cytokinin alone or in combination with 0.1 M sucrose. TDZ was effective than KIN and BAP in improving the postharvest life of the I. germanica scapes by 5.4 days as compared to the control (untreated scapes held in distilled water). This was because of the minimum percentage of bud abortion by TDZ application. Cytokinin application resulted in increased antioxidant activity, higher protein and phenolic content, besides a decrease in specific protease activity and a-amino acids in the tepal tissues. Application of TDZ resulted in the maximum increase in the superoxide dismutase, catalase and ascorbate peroxidase activity in the tepal tissues. The scapes treated with BAP and KIN maintained higher carbohydrate content in the tissue samples as compared to control and TDZ treated scapes. TDZ and BAP application resulted in increased membrane stability because of the decreased lipoxygenase activity which prevented membrane lipid peroxidation. Among the cytokinins tested, TDZ proved to be the promising cytokinin in improving the postharvest performance of beautiful flowers of I. germanica scapes.

6-Benzylamino purine outperforms Kinetin and Thidiazuron in ameliorating flower longevity in Calendula officinalis L. by orchestrating physiological and biochemical responses

“…Higher sugar content was maintained in the tissue samples treated with various cytokinins consistent with the earlier findings which reported a correlation between carbohydrate accumulation and flower longevity by cytokinin application in various flowers such as Gladiolus, Iris, Nicotiana, Gerbera, and Rosa (van Doorn and Woltering, 2008;Ahmad et al, 2018;Tahir et al, 2019;Hemati et al, 2019;Ramtin et al, 2019). Cytokinins maintain high sugar content in petal tissues by enhancing the sink strength, thus inhibiting the mobilization of sugars from the floral parts to ovary during nutrient remobilization (van Doorn and Woltering, 2008).…”

“…Exogenous application of cytokinins and TDZ increased the longevity of cut Calendula flowers significantly. Cytokinins could improve flower longevity by affecting many physiological processes such as free radical formation, membrane stability, water balance and protein metabolism (Lama et al, 2013;Salleh et al, 2016;Ahmad et al, 2018;Tahir et al, 2019). Benzyl adenine (BA) application delayed flower senescence by reducing the abscisic acid (ABA) production, which is known to get raised during flower senescence in both ethylene sensitive and insensitive flowers (Trivellni et al, 2011;Ibrahim et al, 2019).…”

“…Benzyl adenine (BA) application delayed flower senescence by reducing the abscisic acid (ABA) production, which is known to get raised during flower senescence in both ethylene sensitive and insensitive flowers (Trivellni et al, 2011;Ibrahim et al, 2019). Application of Adenine and phenyl urea derivatives have been reported to delay senescence in various cut flowers such as Iris, Dahlia, Gerbera, chrysanthemum, Hemerocallis, Eustoma, Anthurium and Nicotiana (van Doorn and Woltering, 2008;Danaee et al, 2011;Hatamzadeh et al, 2012;Ahmad and Tahir, 2016;Reid and Wu, 2018;Ahmad et al, 2018;Bergmann et al, 2018;Tahir et al, 2019). Cytokinins application might increase flower dimensions and improve flower coloration by supplying more photosynthates to the flower head.…”

“…The reduced LOX activity resulted in maintenance of adequate phospholipids, proteins and thiols by preventing the seepage of proteases from vacuoles into the cytoplasm (Macnish et al, 2010;Liu et al, 2016a;Dek et al, 2017). Cytokinin mediated enhanced membrane integrity can also be attributed to its involvement in maintenance of high water content, antioxidant system and reduced peroxidation rates in tissues, which are greatly affected by the stresses like senescence (Ahmad et al, 2018;Honig et al, 2018). Studies on senescence regulation in C. officinalis, showed that BAP could minimize the reduction in MSI values (Kaur et al, 2015).…”

“…Application of postharvest preservatives that downregulate the protease activity can be suggested as a strategy for extending the vase life and minimizing postharvest losses of flowers (Dwivedi et al, 2016). External application of cytokinins was found very effective in delaying senescence of various cut flowers such as Iris, Phalaenopsis and Nicotiana by arresting degradation of proteins and chlorophyll (Ahmad et al, 2018;Chen et al, 2018;Tahir et al, 2019). Indeed, cytokinins extended the longevity of Andrepogon and Nicotiana flowers not only by preventing protein degradation but also by inhibiting the activity of proteases.…”