Investigating Evolution and Balance of Grape Sugars and Organic Acids in Some New Pathogen-Resistant White Grapevine Varieties

Abstract

Breeding technologies exploiting marker-assisted selection have accelerated the selection of new cross-bred pathogen-resistant grapevine varieties. Several genotypes have been patented and admitted to cultivation; however, while their tolerance to fungal diseases has been the object of several in vitro and field studies, their productive and fruit composition traits during ripening are still poorly explored, especially in warm sites. In this study, five white pathogen-resistant varieties (PRVs) listed as UD 80–100, Soreli, UD 30–080, Sauvignon Rytos, Sauvignon Kretos were tested over two consecutive seasons in a site with a seasonal heat accumulation of about 2000 growing degree days (GDDs), and their performances were compared to two Vitis vinifera L. traditional varieties, Ortrugo and Sauvignon Blanc. Berries were weekly sampled from pre-veraison until harvest to determine total soluble solids (TSS) and titratable acidity (TA) dynamics. All tested PRV exhibited an earlier onset of veraison and a faster sugar accumulation, as compared to Ortrugo and Sauvignon Blanc, especially in 2019. At harvest, Sauvignon Blanc was the cultivar showing the highest titratable acidity (8.8 g/L). Ortrugo and PRV varieties showed very low TA (about 4.7 g/L), with the exception of Sauvignon Rytos (6.5 g/L). However, data disclose that Sauvignon Rytos higher acidity at harvest relies on higher tartrate (+1.1 to +2.2 g/L, as compared to other PRV), whereas in Sauvignon Blanc, high TA at harvest is due to either tartaric (+1 g/L, compared to PRV) and malic (+2.5 g/L, compared to PRV) acid retention. Overall, Sauvignon Rytos is the most suited PRV to be grown in a warm climate, where retaining adequate acidity at harvest is crucial to produce high-quality white wines. Nevertheless, canopy and ripening management strategies must be significantly adjusted, as compared to the standard practice employed for the parental Sauvignon Blanc.

Sustainable Viticulture on Traditional ‘Baran’ Training System in Eastern Turkey

“…Zhang et al [27] showed that among the five varieties of table grapes grown in China, fructose content is slightly higher than glucose and both sugars, accounting for 96.00-98.00% of the total sugar contents in grape berries. Studies also indicate that main sugars of grape berries are fructose and glucose and their ratio was found to be much closer to each other in grape cultivars [28,29]. Sensoy et al [30] and Eyduran et al [25] showed that glucose and fructose content are close to each other in grape cultivars.…”

Study of the Influence of Abiotic and Biotic Stress Factors on Horticultural Plants

“…Authors described the impact of stress caused by both climate change and human activity resulting in disorder of the optimum temperature (low-and high-temperature stresses), water balance (water and drought stress and irrigation) and the subsequent disturbance of soil parameters. The SI gathers eleven research papers [1][2][3][4][5][6][7][8][9][10][11] and one review [12]. Three papers were dedicated to cold stress, two to salt stress, two to inorganic pollutants such as metals and phosphate (Phi), three to climate change (i.e., high temperature, water and drought stress) and two to irrigation.…”

“…In the presented SI, the most frequently applied morphological features were: seed germination, plant growth, leaf and berry area, leaf number, stem diameter and plant dry weight [1][2][3]5,[7][8][9][10][11]. Anatomical characteristics were based mainly on the evaluation of epidermis and mesophyll quality and number of cells and chloroplasts [8].…”

“…Anatomical characteristics were based mainly on the evaluation of epidermis and mesophyll quality and number of cells and chloroplasts [8]. Physiological aspects were focused on water content in leaves, mineral elements (nutritional elements and heavy metals, e.g., N, P, K, Mg, Ca, Mn, Fe, Cu, Na, Cl, Co, Cr, Ni, Pb), photosynthetic pigments content (chlorophylls a and b, carotenoids), polyphenolic compounds content (e.g., polyphenols, phenolic acids and flavonoids), soluble sugars, acids and proline contents and plant growth regulators (e.g., abscisic acid, indole-3-acetic acid, gibberellin A3) [1][2][3][4][5][6][7][8][9][10][11]. Biological traits were mostly lipid peroxidation (i.e., content of malondialdehyde; MDA), level of reactive oxygen species (ROS, e.g., H 2 O 2 and O 2 −• ), activity of antioxidative enzymes (e.g., superoxide dismutase, peroxidase and catalase) and content of non-enzymatic compounds (e.g., vitamin C and lycopene) [2,[4][5][6][7][8][9][10][11].…”

“…Accumulation of proline was observed in salinity stress after chitosan (CTS) application [2], in low temperature stress (kale, Brassica oleracea var. acephala) [3] and in the Phi supply (potato, Solanum tuberosum) [4].…”