507 EXOGENOUS CYTOKININ APPLICATION INCREASED THE CAPSAICIN AND ASCORBIC ACID CONTENT IN PEPPER FRUIT Mostafakamal SHAMS 1 , Ertan YILDIRIM 1 , Melek EKINCI 1 , Guleray AGAR 2 , Metin TURAN 3 , Raziye KUL 1 1 Department of Horticulture, Faculty of Agriculture, Atatürk University, Erzurum, Turkey 2 Department of Biology, Faculty of Science, Atatürk University, Erzurum, Turkey 3 Department of Genetic and Bioengineering, Yeditepe University, Istanbul, Turkey Corresponding author email: ertanyil@atauni.edu.tr Abstract Chili peppers synthesize capsaicin and accumulate it in the fruits. Many biochemical studies have been done in the field of capsaicin biosynthesis in chili peppers. The levels of capsaicin vary among chili pepper cultivars, and it is also affected by environmental conditions. The present study assayed the effect of cytokinin on the capsaicin and ascorbic acid content of Capsicum annum var ʻIlicaʼ (pungent pepper) in the greenhouse. Cytokinin levels include 0, 50 and 100 μM of Benzyl amino purine and the treatments were applied at every 10 days until the harvest beginning 5 days after planting. The results of this study monitored that cytokinin (benzyl amino purine) treatment increased the capsaicin and ascorbic acid content in pepper fruits as compared to the control but decreased the fruit number per plant. Key words: ascorbic acid, capsaicin, fruit, pungent pepper. INTRODUCTION Hot pepper burning sensation induced by the presence of acid amides, collectively known as capsaicinoids, that are formed from phenylalanine and valine or leucine. Capsaicin and dihydro indicate more than 90% of the total capsaicinoid content in most pungent peppers (Ben-Chaim et al., 2006). Capsaicinoid biosynthesis is restricted to the genus Capsicum (Stewart et al., 2007). Capsaicin content raises slowly during fruit development reaching peak levels at 40 to 50 days after planting (Contreras-Padilla and Yahia, 1998), after which it gravitates to deteriorate into secondary compounds due to peroxidase action (Bernal and Barceló, 1996). For increasing or improving pungent compound production, a research has revealed that hydric stress ameliorates capsaicinoid levels, because water deficit affects the phenylpropanoid pathway (Estrada et al., 1999). Hydric stress can raise capsaicin levels by increasing activity of the enzymes phenylalanine ammonia-lyase (PAL), cinnamic acid-4-hydroxylase (C4H), and capsaicinoid synthetases (CS), all engaged in capsaicin biosynthesis (Sung et al., 2005). Monforte González et al. (2010) found that application of nitrate can increase the capsaicin biosynthesis, but potassium application had not a significant effect on it. Ascorbic acid is very abundant in pepper fruits and is the main component of vitamin C. Its content is highly varying among cultivar and ripening stage (Bae et al., 2014). Cytokinin is a hormone of plants that adjusts growth and developmental cycles. It has an important role on the chlorophyll status in plants (Lim et al., 2007). Exogenous treatment of N6-benzyl amino purine (BAP) on the eggplant increased its tolerance under salt stress by decreasing the O 2 - and malondialdehyde production rate (Wu et al., 2014). Application of BAP in the in vitro culture increased the comptothecin content in shoots and roots of Ophiorrhiza rugosa var. decumbens (Vineesh et al., 2007). It was reported that the application of BAP increased the shikonin formation in Onosma paniculatum cultured cell (Ding et al., 2004). So BAP has an exclusive effect on the plant growth and secondary metabolites production in the plants. The results of the literature review suggest that abiotic and biotic parameters could affect the secondary metabolites production in plants. Up to now a research has not been done on the Scientifc Papers. Series B, Horticulture. Vol. LXII, 2018 Print ISSN 2285-5653, CD-ROM ISSN 2285-5661, Online ISSN 2286-1580, ISSN-L 2285-5653