EFFECTS OF DIFFERENT IRRIGATION LEVELS AND PROLINE TREATMENTS ON ORGANIC ACIDS AND SECONDARY METABOLITES OF PEPPER (Capsicum annuum L. cv. Yalova Yağlık 28)

Abstract

Pepper is quite sensitive to water stress, thus changes in irrigation levels may have significant effects on yield, organic acids and phenolics of peppers. Improper irrigation levels may generate a water stress and resultant stress then create serious oxidative damages on cell membranes. Such damages can be prevented with proline-like antioxidative substances. This study was conducted in Çanakkale -Turkey to investigate the effects of different irrigation levels and proline treatments on yields, quality parameters and organic acid composition of pepper (Capsicum annuum L. cv. Yalova Yağlık 28) in the years of 2013 and 2014. Experiments were conducted in randomized blocks split plots experimental design with 3 replications. Three different irrigation levels were arranged as to apply certain percentages of total evaporation from Class-A pan (Kcp50, Kcp100, Kcp150). Proline treatments (12 mM) were applied at 3 different growth stages (three equal portions on 20, 30 and 40 th days, single treatment on 30 th day and single treatment on 40 th day of growth). In both years of the experiments, decreasing citric acid contents and increasing ascorbic acid contents (in the first year of experiments, Kcp50=84.54, Kcp100=175.48, Kcp150=198.92 mg/100g) were observed with increasing irrigation levels. Different irrigation levels and proline treatments had significant effects on yield (g/m 2 ), total phenolics (mg/100g), soluble solids content (SSC, %) and internal proline content (µmol/g) of pepper fruits. Adversely affected parameters as yield (g/m 2 ) and ascorbic acid content due to limited irrigation positively affected with some proline treatments.

The influence of acute water stresses on the biochemical composition of bell pepper (Capsicum annuumL.) berries

“…In our experiment no significant changes in the berry content of both citric and malic acids was detected (Table 2). Our results appear in contrast with what reported by Sariyer et al 59 . which, by applying reduced irrigation regimes, detected an increase of citric acid in a Turkish cultivar of C. annuum .…”

Genetic Regulation, Environmental Cues, and Extraction Methods for Higher Yield of Secondary Metabolites in Capsicum

“…Proline treatments and decreased irrigation independently led to increase in total phenolics content in C. annuum . The PAL gene was highly expressed under gradual water deficit after initial waterlogging as compared to other irrigation regimes .…”

“…121 Proline treatments and decreased irrigation independently led to increase in total phenolics content in C. annuum. 122 The PAL gene was highly expressed under gradual water deficit after initial waterlogging as compared to other irrigation regimes. 123 Drought stress improved anthocyanin levels in C. annuum leaves, but after treatment with ascorbic acid, anthocyanins were reduced and carotenoid levels were increased.…”