Effects of Girdling and Foliar Fertilization with K on Physicochemical Parameters, Phenolic and Volatile Composition in ‘Hanxiangmi’ Table Grape

Abstract

Aroma is one of the most important indicators of grape quality. Girdling and foliar fertilization with K (K2O) are common agronomic practices applied to improve berry quality in grape production. However, little is known about its effect on the accumulation and biosynthesis of the entire aromatic profile. Our study was aimed to explore the influences of girdling and foliar fertilization with K (alone or in combination) on the general properties, phenolic composition, volatile free aroma compounds, spatial and temporal expression of terpene-related genes and sensory properties in ‘Hanxiangmi’ table grape. In this study, we found that girdling and foliar fertilization with K (alone or in combination) facilitated fruit enlargement and increased the accumulation of phenolic compounds in skin. The combination treatment of girdling and foliar fertilization with K significantly promoted the concentrations of total soluble solids (TSS) in the pulp and proanthocyanidins in the berry skin, and had a lower titratable acidity (TA) compared to those of the control. In contrast, girdling treatment alone increased the concentrations of titratable acidity. Volatile free aroma composition analysis revealed that the combination treatment increased the volatile compounds and concentrations significantly, most notably in terpenes, such as nerol, citronellol and linalool. Spatial and temporal expression analysis showed that the expression level of VvDXS was significantly correlated with linalool and total terpenes concentrations, as a result of which, we speculated that VvDXS is the candidate gene for the regulation of important grape terpenes. We hope that our results can direct farmers to better apply girdling and foliar fertilization with K in grape production.

Effects of Table Grape Cultivars on Fruit Quality and Aroma Components

“…The content of total anthocyanins in red grape berries was determined using the pH differential method with dimethyl anthocyanin (mg/kg) [ 13 ]. The flavonoid content was determined using the sodium nitrite-aluminum nitrate method [ 19 ].…”

“…Studies have shown that terpenes, C13 isoprene, methoxypyrazine, C6-alcohol, aldehydes, esters, and mercaptans are among the most important compounds that contribute to the aroma of grapes [ 12 ]. Among these compounds, terpenes and esters provide floral and fruity characteristics to grapes, while alcohols and C6 aldehydes contribute to a herbaceous flavor [ 13 ]. Table grapes are classified into groups depending on the type of aroma [ 14 ].…”

Identification of ABA Signaling Pathway Genes and Their Differential Regulation in Response to Suboptimal Light Stress in Grape (Vitis vinifera L.)

“…The experiments were performed with 5-year-old 'Yinhong' table grape vines between May and July 2021 in an irrigated vineyard at Cixi, Zhejiang, China (30 • 16 6.59 N, 121 • 25 2.18 E). The physical and chemical properties of the soil were as follows: soil type, clayey soil; pH, 6.4; soil depth, 102 cm; total organic matter content, 25 g•kg −1 ; basic nitrogen, 202 mg•kg −1 ; available phosphorus, 35 mg•kg −1 ; available potassium, 114 mg•kg −1 ; soil bulk density, 112.3 g•cm −1 ; and groundwater level, 55-60 cm [37]. The soil is a typical marine sedimentary plain soil, with a deep and sparse soil layer and good permeability.…”

Effects of foliar‐sprayed potassium dihydrogen phosphate on accumulation of flavonoids in Cabernet Sauvignon (Vitis vinifera L.)

“…and Mpelasoka et al 19 . P and K participate in the transport of sugar and acid, the response of hormones, and the synthesis of polyphenols related to color and aroma 23,24 . Moreover, exogenous P and K fertilizers can promote the accumulation of soluble solids and anthocyanin in grapes 24,25 …”

“…16,21,22 The role of P and K nutrition on yields and fruit quality in grapevines has been reviewed by Brunetto et al 11 and Mpelasoka et al 19 P and K participate in the transport of sugar and acid, the response of hormones, and the synthesis of polyphenols related to color and aroma. 23,24 Moreover, exogenous P and K fertilizers can promote the accumulation of soluble solids and anthocyanin in grapes. 24,25 Traditionally, most plants mainly take up P and K applied to the soil through the roots.…”