Nan Jia

Grafting is a crucial strategy for improving stress resistance and fruit quality in grape production. However, our understanding of the specific roles of rootstocks in graft establishment, vine growth, and nutrient acquisition remains limited. This study evaluated the relevant traits of three worldwide wine grape cultivars grafted onto eight rootstocks, aiming to clarify the inherent characteristics of individual rootstocks and provide insights for their better understanding and utilization. The rootstock showed significant effects on petiole mineral levels with consistent patterns, even across developmental stages and years. For example, 5BB consistently accumulated Ca at all stages, while Beta demonstrated strong Mn uptake. Additionally, 101-14M and 110R specifically enriched B at the flowering stage. The scion showed a great influence on post-graft growth and mineral absorption. Specifically, ‘Cabernet Sauvignon’ (CS) exhibited superior performance in macronutrient accumulation, whereas ‘Petit Verdot’ (PV) showed distinct advantages in micronutrient. From flowering to veraison, the dominant mineral profile shifted from N, P, and B to Ca, Mg, and Cu, with the scion’s influence becoming evident at veraison. These findings enhance our understanding of rootstocks and provide a reference for their utilization.

The muscat aroma of grape is largely determined by terpenoid volatiles. However, its genetic basis in ‘Muscat Hamburg’ remains unclear. We performed comparative volatile metabolomics between ‘Muscat Hamburg’ and ‘Red Globe’ across berry development, identifying 127 differentially abundant metabolites, with upregulated ones enriched in the monoterpenoid pathway. Using an F1 segregating population (264 progeny), we quantified four key monoterpenoids (α-terpineol, linalool, geraniol, and cis-linalool oxide) over two consecutive years. Using a high-density genetic map with 7872 SNP markers generated via SLAF-seq, we detected stable major QTLs for α-terpineol, linalool, and geraniol on LG5, and a novel QTL for cis-linalool oxide on LG14. Expression analysis revealed that the transcript levels of VvDXS and VvGGPPS1 were significantly higher in ‘Muscat Hamburg’ than in ‘Red Globe’ at ripening. Heterologous overexpression in tomato enhanced terpenoid aroma accumulation without affecting fruit development. These results indicate that VvDXS and VvGGPPS1 play a crucial role in the formation of the aroma in the ‘Muscat Hamburg’ variety.

Protected cultivation ensures stable conditions for premium table grape production but involves high initial costs. A double-cropping system enabling a delayed secondary harvest within a single season may increase yield and accelerate cost recovery, yet the characteristics of the secondary harvest remain poorly understood. In the paper, we compared the fruit quality of FH (first harvest) and SH (second harvest) of the early-ripening cultivar ‘Chunguang’ produced in northern China. The results showed that the SH contributed to a 23.9% increase in total yield. SH berries were smaller, with a mean weight of 6.7 g, and exhibited darker skins, higher anthocyanin content (11 mg g⁻¹ fresh skin), higher seed number, higher accumulated sugar components, and 4.55 mg L⁻¹ of titratable acids. This study provides the first evidence that a secondary harvesting system under protected cultivation can simultaneously enhance yield and fruit quality in northern grape-growing regions.

Selecting an appropriate rootstock for a specific scion cultivar is an efficient way to improve both yield and berry quality in viticulture. This study aimed to provide practical guidance for rootstock selection in the cultivation of the table grape cultivar ‘Fengguang’. The mature scions of this cultivar were grafted onto hardwood cuttings of eight different resistant rootstocks, which included 101-14M, 110R, 188-08, 3309C, 5BB, 5C, SO4, and Beta, with the own-rooted vines as control. Graft compatibility, growth vigor, yield performance, and fruit quality were compared and analyzed among the different grafting combinations. The results suggested that vines on 101-14M, 5BB, and Beta obtained higher germination rates of scions, better healing rates of the mating interface, and greater generation rates of root callus. Among these, vines on 5BB exhibited the largest scion trunk cross-sectional diameter. Furthermore, SO4 demonstrated the most significant improvement in yield, with an average increase of 13.54% compared to the control. Regarding berry quality, 101-14M significantly enhanced berry mass, pressure resistance, and flesh firmness relative to the controls, with average improvements of 7.67%, 11.34%, and 29.86%, respectively. Based on a comprehensive evaluation of yield and fruit quality indicators, 101-14M gained the highest value. In conclusion, 101-14M is preferentially recommended for grafting cultivation of ‘Fengguang’ vines. These findings could provide practical guidance for the cultivation of table grape cultivars.

Selecting appropriate rootstocks can enhance the adaptability and fruit quality of grafted grapevines. However, grafting studies on ‘Red Globe’, one of the major cultivated cultivars, remain limited, particularly those involving long-term and comprehensive evaluations. The present research grafted ‘Red Globe’ onto four rootstocks—‘101-14’, ‘188-08’, ‘110R’, and ‘3309C’—and systematically compared graft union healing following hardwood grafting, field performance of grafted vines, vegetative growth of mature vines, and fruit phenotypic and quality traits across multiple years. The results showed that ‘101-14’ promoted the accumulation of organic acids, which reached 1.1% in 2023, and caused an increased tendency for berry detachment from the peduncle. The RG/110R combination exhibited a higher CFI, 0.8 on average, at the basal section, and promoted shoot thickening. RG/3309C was found to have a larger shoot length exceeding 600 cm, and a significant increase in fruit weight to nearly 13 g. The grafts on ‘188-08’ showed the highest survival rate of 74% among the graft combinations, and enhanced fruit quality, as evidenced by elevated TSS (16 °Brix) and firmer pulp texture, indicating that ‘188-08’ may serve as a valuable rootstock for enhancing the local adaptability and fruit quality of ‘Red Globe’ grapevines.

Knowledge about the growth vigor of grapevine rootstocks is required for scion-based rootstock selection and rootstock breeding. We performed this trial aiming to evaluate the multiplication and growth vigor of several rootstocks. Thirty-one rootstock genotypes were compared on their multiplication characteristics, phenological periods, and growth indicators across three consecutive seasons. The results suggested that the cuttings of most rootstocks had callus-forming indices (CFIs) over 0.5 except for ‘188-08’ (0.28). The rooting rate of ‘420A’ was 5%, while that of the rest of the rootstocks was greater than 48%. The internode lengths of the one-year-old vines were positively correlated with those (as well as cane lengths and pruning weights) of the adult vines. These rootstocks were grouped into three clusters based on the growth measurements across three seasons. Eight combinations of genetic backgrounds showed various effects on the growth indicators. The high-vigor cluster includes ‘1103P’, ‘5BB’, ‘225Ru’, etc.; the medium-vigor cluster includes ‘Dogridge’, ‘101-14M’, ‘Fercal’, etc.; and the low-vigor cluster includes ‘Gloire’, ‘3309C’, ‘Ganzin1’, etc. The Vitis berlandieri parentage showed a higher vigor heredity, while the V. riparia showed a lower vigor heredity. These findings would contribute to rootstock nursery construction and provide references for vigor-based rootstock selection for grafts and parent selection for rootstock breeding.

Protected grape cultivation develops rapidly because of huge economic benefits. However, adverse environmental conditions (insufficient sunlight, high temperature, etc.) in protected cultivation led to low-quality berries. This study aimed to evaluate the effects of berry thinning on the quality attributes of two table grape cultivars (Baoguang and Cuiguang) under linkage greenhouse conditions. Three treatments (L, light berry thinning; M, moderate berry thinning; H, heavy berry thinning) were compared with the control (C, no berry thinning). Berry thinning increased berry weight, total soluble solids (TSS), fructose, glucose, the ratio of TSS to titratable acidity (TA), anthocyanin contents, berry firmness, and mineral contents (Ca, Fe, Na, Mg). Conversely, TA and organic acid profiles were decreased by berry thinning. Cultivars showed significant effects on most of the berry quality parameters. The interaction of cultivars by berry-thinning treatments affected sugar and acid components, anthocyanin contents, and mineral elements.