Alteration of the Content of Primary and Secondary Metabolites in Strawberry Fruit by Colletotrichum nymphaeae Infection

Abstract

The effects of infection with Colletotrichum nymphaeae , the causative agent of strawberry black spot, were studied on two strawberry cultivars: susceptible 'Elsanta' and tolerant 'Honeoye' cultivars. Four treatments were established: (1) artificial inoculation; (2) spray application of pyraclostrobin + boscalid (Signum); (3) foliar spraying with calcium (Stopit); and (4) control (spraying with water). Primary metabolites (sugars and organic acids) and secondary metabolites (phenolic compounds) were determined in strawberry fruit with the use of HPLC-MS(n). Infected fruit accumulated large amounts of total sugars and low levels of organic acids. The sugar/acid ratio was higher in the infected and in Ca-treated strawberries. The contents of ellagic acid derivatives, flavonols, oligomeric procyanidins, flavan-3-ols, and total phenolics were highest in inoculated strawberry fruit. Results indicated that fungicide and calcium sprayings did not alter polyphenolic levels in plant tissue.

Alternative products against anthracnose affect selected primary and secondary metabolites in strawberry fruit

“…The content of sucrose was much lower (from 0.67 in acetic acid treated infected fruits to 5.11 g kg −1 FW in non-infected control). Mikulic-Petkovsek et al [21] reported similar results for two different strawberry cultivars. Treatment (P = 0.009) and infection (P = 0.000) significantly affected the content of total sugars.…”

“…For each treatment, six repetitions were carried out (n = 6); each repetition included several fruits. For the extraction of primary metabolites, 5 g fruit was homogenized in 25 mL of double-distilled water using an Ultra-Turrax T-25 (Ika-Labortechnik) and left for 30 min at room temperature as reported by Mikulic-Petkovsek et al [21]. After the extraction, the homogenate was centrifuged (Eppendorf Centrifuge 5810 R) at 12,000 rpm for 7 min at 10…”

“…• C. The mobile phase was double-distilled water, and the flow rate was 0.6 mL min −1 ; the total run time was 30 min, and a refractive index (RI) detector was used to monitor the eluted carbohydrates as described by Mikulic-Petkovsek et al [21]. Organic acids were analyzed with the same HPLC system, equipped with a UV detector set at 210 nm, using a 300 mm × 7.8 mm i.d.…”

“…Organic acids were analyzed with the same HPLC system, equipped with a UV detector set at 210 nm, using a 300 mm × 7.8 mm i.d. Rezex ROA-organic acid H+ (8%) column from Phenomenex, as described by Mikulic-Petkovsek et al [21]. The column temperature was set at 65…”

“…The extraction of fruit samples was performed as described by Mikulic-Petkovsek et al [21] with some modification. Phenolic compounds (flavonoids and phenolic acids) were analyzed in whole strawberry fruit.…”