Effect of the Application Time of Accentuated Cut Edges (ACE) on Marquette Wine Phenolic Compounds

Cold-hardy interspecific hybrid grape varieties (Vitis spp.) have distinctive chemical compositions such as high acidity, a high content of anthocyanin diglucoside and a low condensed tannins content, compared to Vitis vinifera varieties. Considering the importance of phenolic compounds on the quality of red wine, a mechanical maceration technique, accentuated cut edges (ACE), has been evaluated when applied directly to crushed grapes (ACE-C), and 24 h before pressing (ACE-P), to improve the extraction of phenolic compounds. Samples were collected at crushing, bottling, and after five months of aging. Phenolic compounds and color characteristics of the wines were analyzed by high-performance liquid chromatography (HPLC) with diode array and fluorescence detectors and UV-Visible spectrophotometry. The color intensity, non-anthocyanin monomeric compounds and total iron-reactive phenolics content increased after applying ACE, compared to the control (CTL) after aging, and was significantly higher (37%) after ACE-C, compared to ACE-P. However, the concentration of condensed tannins was below the limit of detection in all the samples, indicating that ACE did not help their extraction or further interactions occurred with disrupted cell wall material. Applying ACE at crushing was considered as the optimum time to achieve a higher color stability in Marquette red wines.

Floral Aromatics of Ptelea: Chemical Identification and Human Response

Many members of the citrus family (Rutaceae) are valued for the aromatic compounds emitted by their flowers. Ptelea species are unusually cold-hardy members of the Rutaceae, but conflicting descriptions of the fragrance of their unisexual flowers may discourage the use of these trees. We analyzed floral volatiles and human response to these chemicals to test the hypothesis that the fragrance of staminate and pistillate flowers of these species differs. Gas chromatography and mass spectrometry showed that most volatile chemicals emitted by flowers of Ptelea trifoliata and Ptelea crenulata are monoterpenes, sesquiterpenes, and esters. Most volatiles were emitted from flowers of both sexes, but ethyl benzoate and estragole were emitted only from pistillate flowers. When concentrations of aromatics differed between sexes, they were higher for pistillate flowers, except for cis-3-hexenyl butanoate and an unidentified terpene. For P. crenulata and P. trifoliata, respectively, 81% and 77% of survey responses were from volunteers who liked the fragrance. Panelists most frequently described the scent of flowers of P. crenulata of both sexes with the words citrus, lime, and sweet. Panelists distinguished between pistillate and staminate flowers of P. trifoliata, describing the odor of pistillate flowers most frequently with the words damp-earthy, spicy, and sweet; staminate flowers were perceived as light, fresh, grassy, and pleasant. This work represents the first analysis of floral volatiles of P. crenulata and resolves conflicting prior reports regarding the floral fragrance of P. trifoliata. We conclude that differences among people rather than the sex of flowers account for conflicting prior reports of floral fragrance. The scents of flowers of P. crenulata and P. trifoliata appeal to most people and are horticultural assets of these trees.

Growing Feijoa Fruit in Florida

Feijoa is often found in central and north Florida landscapes as a durable and cold-hardy plant for hedges and foundation plantings, and as a dooryard fruit. Its value as a potentially heavy producer of flavorful fruits (and flavorful flowers) is frequently overlooked due to issues in pollination and limited genetic improvement. This new 5-page publication of the UF/IFAS Horticultural Sciences Department describes the opportunity and limitations of feijoa as a horticultural crop.https://edis.ifas.ufl.edu/hs1424

Phenological diversity in wild and hybrid grapes (Vitis) from the USDA-ARS cold-hardy grape collection

Wild grape relatives and hybrids have been useful in breeding for tolerance to biotic and abiotic stress, however, few studies have emphasized wild and hybrid grapevines for phenological diversity. Utilization of phenological diversity in grapevine breeding could facilitate expansion of grape production into more varied climate regions. Budbreak, bloom, and veraison observations for 1583 accessions from 20 taxa from the United States Department of Agriculture Vitis collection in Geneva, New York, USA. Genotypic and species variation were estimated. Vitis vinifera ancestry was estimated in Vitis hybrids using principal components analysis. Observations ranged 26.6–162.1 (79–141 JD) with an average of 82.6 GDD (118 JD) for budbreak, 206.8–1055.2 (141–222 JD) with an average of 371.9 GDD (163 JD) for bloom, and 849.9–1627.0 (202–290 JD) with an average of 1207.9 GDD (235 JD) for veraison. Seasonal correlations were high for bloom and veraison (0.85–0.95) and moderate for budbreak (0.61–0.65). Moderate heritability was estimated for veraison (0.62) and bloom (0.49), and weak heritability for budbreak (0.2). The species effect was greatest in bloom and explained 42% of the variation, with increasing bloom GDD associated with increasing contribution of V. vinifera in Vitis hybrids.

Blueberry bud freeze damage detection using optical sensors: Identification of spectral features through hyperspectral imagery

BACKGROUND: Highbush blueberry (Vaccinium corymbosum), the species primarily grown in the state of Washington, U.S., is relatively cold hardy. However, low temperatures in winter and early spring can still cause freeze damage to the buds. OBJECTIVE: This study intended to explore hyperspectral imaging (HSI) for detecting freeze induced bud damage. Blueberry buds (c.v. Duke) were collected over two seasons and tested in the laboratory to detect damage at four typical phenological stages. METHODS: The HSI data was acquired via line scan HSI system with spectral wavelength ranging from 517 to 1729 nm for buds grouped into either normal or injured mortalities. The successive projection algorithm was employed for pertinent feature wavelength selection. Analysis of variance and linear regression were then applied for evaluating sensitivity of feature wavelengths. RESULTS: Overall, five salient wavelengths (706, 723, 872, 1384, and 1591 nm) were selected to detect bud freeze injury. A quadratic discriminant analysis method-based analysis verified reliability of these five wavelengths in bud damage detection with overall accuracy in the ranges of 64 to 82%for the test datasets of each stage in two seasons. CONCLUSIONS: This study indicated potential of optical sensing to identify the injured buds using five salient wavelengths.

Dehydrins and Soluble Sugars Involved in Cold Acclimation of Rosa wichurana and Rose Cultivar ‘Yesterday’

Rose is the most economically important ornamental plant. However, cold stress seriously affects the survival and regrowth of garden roses in northern regions. Cold acclimation was studied using two genotypes (Rosa wichurana and R. hybrida ‘Yesterday’) selected from a rose breeding program. During the winter season (November to April), the cold hardiness of stems, soluble sugar content, and expression of dehydrins and the related key genes in the soluble sugar metabolism were analyzed. ‘Yesterday’ is more cold-hardy and acclimated faster, reaching its maximum cold hardiness in December. R. wichurana is relatively less cold-hardy, only reaching its maximum cold hardiness in January after prolonged exposure to freezing temperatures. Dehydrin transcripts accumulated significantly during November–January in both genotypes. Soluble sugars are highly involved in cold acclimation, with sucrose and oligosaccharides significantly correlated with cold hardiness. Sucrose occupied the highest proportion of total soluble sugars in both genotypes. During November–January, downregulation of RhSUS was found in both genotypes, while upregulation of RhSPS was observed in ‘Yesterday’ and upregulation of RhINV2 was found in R. wichurana. Oligosaccharides accumulated from November to February and decreased to a significantly low level in April. RhRS6 had a significant upregulation in December in R. wichurana. This study provides insight into the cold acclimation mechanism of roses by combining transcription patterns with metabolite quantification.

Viticultural Performance of Hybrids and Vitis vinifera Varieties Established in Annapolis Valley (Nova Scotia)

(1) Background: Cold-hardy interspecific hybrid grapes (CIHG) are well adapted to the Annapolis Valley edaphoclimatic conditions. The main characteristics of CIHG are the high bud hardiness tolerance to winter frost, the short growing cycle, and the good tolerance to cryptogamic diseases. Based on local experience, the Vitis vinifera varieties should be grown in the warmest areas of the Annapolis Valley (Nova Scotia, Canada). Despite this, there is little scientific evidence that shows the viticultural behavior of these varieties under the edaphoclimatic conditions of this valley. (2) Methods: Thus, the aim of this research was to evaluate the viticultural behavior of two CIHG (L’Acadie and New York Muscat) and three V. vinifera varieties (Chardonnay, Riesling, and Pinot Noir) growing in the Annapolis Valley over three consecutive seasons. (3) Results: The coldest season (2019) produced a delay in grapevine phenology of at least 18 days for budburst compared to the warm seasons (2017 and 2018). In addition, in the coldest season from budburst to bloom the duration decreased compared to the rest of the seasons. The main phenological stages started earlier in L’Acadie than in the V. vinifera varieties. L’Acadie presented lower N petiole content than the V. vinifera varieties, which conditioned shoot growth in the studied seasons. CIHG presented low B petiole levels and produced musts with low malic acid content, while V. vinifera varieties produced musts with high N content. L’Acadie was the only variety that could bud out, and differentially produced fruit after the spring frost of −2 to −3 °C for 2 h in 2018 in this trial. (4) Conclusions: L’Acadie, and to a lesser extent, Riesling, hold an interesting adaptation to the edaphoclimatic conditions of the Annapolis Valley.

Genetic Variation in Frost Tolerance, Uromycladium acaciae Rust Resistance, and Growth in an Acacia mearnsii Population

Genetic variation in frost tolerance, resistance to the rust fungus Uromycladium acaciae, growth, stem form, and gummosis were evaluated in 110 open-pollinated families of black wattle (Acacia mearnsii De Wild). Families were tested at six frost-prone sites in northern KwaZulu-Natal and southeastern Mpumalanga, South Africa. Frost-hardy provenances were susceptible to rust disease and had poor growth. Locally grown F1 seed sources that originated from cold-hardy Australian seed sources had better growth and were tolerant to rust, but at a cost of lower frost tolerance. Considerable genetic variation was observed between families within seed sources for frost damage (hfm2 = 0.77), rust incidence (hfm2 = 0.89), and height (hfm2 = 0.80). The corresponding narrow-sense heritabilities (hi2) were 0.30, 0.80, and 0.32. Genotype-by-environment interaction levels were low for most traits. Except for a strong genetic correlation between tree height and diameter (0.90), all the pairs of traits had weak to moderate genetic correlations. Recurrent selection will be successful in improving frost tolerance and rust incidence. However, the current population comprises limited germplasm that is both tolerant to frost and resistant to rust. Thus, we recommend infusing germplasm from known cold-hardy Australian provenances into the current population to increase genetic variation for frost tolerance, rust, and growth. Study Implications Black wattle (Acacia mearnsii De Wild) is widely planted in South Africa for bark extract and woodchip exports. The species is prone to frost damage and susceptible to rust fungus Uromycladium acaciae, two major limitations to its cultivation. In this study, 110 open-pollinated families of black wattle originated from its native range in Australia and local South African seed sources were studied for frost and disease tolerance. The results from this study suggest that there is considerable variation within species for frost tolerance and fungal disease. We suggest a tandem selection strategy for black wattle farming in South Africa to increase resistance to frost damage and fungal diseases.

Cold hardiness in grapevines of various ecological and geographical origin

Over past years, grapevine adaptability has become of primary concern due to sharp cold-stressing weather of the unstable climates of Southern Russia accompanied by increasing mean annual temperatures, including higher degrees during plant winter dormancy. This situation causes considerable injury to the generative and vegetative organs in bush vine. Physiological and biochemical studies of the vine plant are of great importance for breeding cold-hardy grape genotypes. The article presents research related to studying cold hardiness in different grape varieties by content dynamics of starch, soluble sugars, abscisic acid and potassium ions in plant bark and buds. We studied grape varieties (interspecies hybrids) of the European-American (Dostoinyi, Krasnostop, Vostorg), West-European (Aligote), East-European (Zarif) and European-Amur-American origins (Kristall). The work aimed to analyse the physiological and biochemical properties of various ecological and geographical-origin grapes in winter time in order to identify the cold-hardiest genotypes. The Krasnostop and Vostorg varieties were ascertained as cold-hardy. Physiological and biochemical assays revealed an important contribution of water-soluble sugar-producing starch hydrolysis to low-temperature adaptation in Krasnostop and Vostorg, with the sugar content increasing 2.7-2.9 times. Krasnostop and Zarif were found to elevate the sucrose osmoprotectant winter level 4.7 and 6.6 times, respectively. All grape varieties decreased the abscisic acid content due to protective functions. Aligote was identified susceptible basing on a 2.3-fold potassium ion increase in frozen bark cell extract. The research conducted establishes the diagnostic value of the abovementioned physiological and biochemical parameters for cold hardiness evaluation in grape varieties.

Tannin Content in Vitis Species Red Wines Quantified Using Three Analytical Methods

Tannin content in red wines is positively correlated with astringency perception and wine grade; however, tannin quantification is one of the main challenges. In this study, tannin content was quantified using three analytical methods in commercial red wines from Vitis vinifera and interspecific cold-hardy hybrids including Marquette, Frontenac, and Petite pearl cultivars. Protein (PP) and methylcellulose precipitation (MCP) methods were compared to a HPLC-DAD method, which is based on the interaction between tannins and a hydrophobic surface (RPC). Frontenac wines were the poorest in tannins and Cabernet sauvignon wines were the richest regardless of the method used. In cold-hardy red wines, the tannin content was higher in Marquette with high alcohol content, which suggested that the tannins were extracted from seeds rather than skins. The high limit of quantification of the PP method and the presence of anthocyanin di-glucosides in cold-hardy wines were parameters suggesting that protein and methylcellulose precipitation methods were neither suitable nor reliable for the quantification of tannins in cold-hardy red wines. The tannin content quantified by RPC was positively correlated to tannin quantified by MCP, suggesting that the RPC method would be relevant for the quantification of tannins in red wines.