Most strawberry flavor studies have examined berries grown in temperate regions with long summer days. Few studies have examined berries harvested in winter months from subtropical regions with shorter photoperiods. Fruits harvested in February and March from two strawberry cultivars, 'Strawberry Festival' and 'Florida Radiance', were examined. Thirty odor active compounds were detected using time-intensity GC-O. Twenty-nine were identified. The major odor active volatiles in both cultivars were 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), methyl butanoate, γ-decalactone, unknown (grassy, LRI 1362, wax), (E)-2-hexenal, linalool, (E,Z)-2,6-nonadienal, geraniol, butanoic acid, methyl 2-methylbutanoate, and ethyl hexanoate. Over 90 volatiles were identified and 54 quantified using GC-MS including 33 esters, 6 alcohols, 5 acids, 3 aldehydes, 3 lactones, 2 ketones, and 2 furanones. Odor activity values (OAVs) were determined for 46 volatiles, of which 22 had OAV > 1. The highest OAVs for 'Strawberry Festival' were ethyl butanoate (461), DMHF (424), methyl butanoate (358), and linalool (102). A 14-member trained panel evaluated quartered fruit using quantitative descriptive analysis to quantify seven sensory attributes. Sensory "strawberry flavor" scores were positively correlated with sensory "sweetness" (R(2) = 0.83) as well as GC-MS methyl 3-methylbutanoate (R(2) = 0.90) and ethyl butanoate (R(2) = 0.96). These cultivars lacked methyl anthranilate and possessed an aroma pattern different from summer-grown strawberries.

Aroma active volatiles in four southern highbush blueberry cultivars ('Prima Dona', 'Jewel', 'Snow Chaser', and 'Kestrel') were determined using solid phase microextraction (SPME) in combination with gas chromatography-olfactometry (GC-O) and identified via GC-PFPD and GC-MS using retention indices of reference compounds and mass spectral data. The aromas of total, unseparated SPME extracts evaluated using GC-O were rated 8.2-9.0/10 for the four cultivars in terms of similarity to the original blueberry homogenates. In terms of GC-O aroma similarity, those aroma active volatile groups characterized as green, fruity, and floral were most intense. Of the 43 volatiles found to have aroma activity, 38 were identified and 13 had not been previously reported in blueberries. Although linalool and (E)-2-hexenal were common major aroma impact volatiles, dominant aroma-active volatiles were different for each cultivar. Principal component analysis confirmed that each cultivar possessed a unique aroma active profile as each cultivar was clustered into a separate score plot quadrant.

The volatile composition of four southern highbush blueberry cultivars ('Primadonna', 'Jewel', 'Snowchaser', and 'FL02-40') grown in two locations (Gainesville and Haines City, FL) and harvested multiple times was investigated. A total of 42 volatiles were identified, including 8 esters, 12 terpenoids, 11 aldehydes, 7 alcohols, and 4 ketones. Twelve of these volatiles are reported for the first time in highbush blueberries, with 10 being positively identified: (Z)-3-hexenal, (E,E)-2,4-hexadienal, (E,Z)-2,6-nonadienal, (E,E)-2,4-nonedienal, methyl 2-methylbutanoate, butyl acetate, 2-methylbutyl acetate, and geranyl acetate. The dominant volatiles were aldehydes followed by terpenoids and esters, with distinct varietal profiles. 'Primadonna' was characterized by a large amount of esters and C-6 aldehydes. In contrast, fewer than 4 esters were found in 'FL02-40' and 'Snowchaser', respectively, but they produced more terpenoids than 'Primadonna' and 'Jewel'. Location and/or harvest date affected the production of volatiles in 'Primadonna', but not so much in the other cultivars.

Key messageA novel TaGW2-A1 allele was identified from a stable, robust QTL region, which is pleiotropic for thousand grain weight, grain number per spike, and grain morphometric parameters in wheat.AbstractThousand grain weight (TGW) and grain number per spike (GNS) are two crucial determinants of wheat spike yield, and genetic dissection of their relationships can help to fine-tune these two components and maximize grain yield. By evaluating 191 recombinant inbred lines in 11 field trials, we identified five genomic regions on chromosomes 1B, 3A, 3B, 5B, or 7A that solely influenced either TGW or GNS, and a further region on chromosome 6A that concurrently affected TGW and GNS. The QTL of interest on chromosome 6A, which was flanked by wsnp_BE490604A_Ta_2_1 and wsnp_RFL_Contig1340_448996 and designated as QTgw/Gns.cau-6A, was finely mapped to a genetic interval shorter than 0.538 cM using near isogenic lines (NILs). The elite NILs of QTgw/Gns.cau-6A increased TGW by 8.33%, but decreased GNS by 3.05% in six field trials. Grain Weight 2 (TaGW2-A1), a well-characterized gene that negatively regulates TGW and grain width in wheat, was located within the finely mapped interval of QTgw/Gns.cau-6A. A novel and rare TaGW2-A1 allele with a 114-bp deletion in the 5′ flanking region was identified in the parent with higher TGW, and it reduced TaGW2-A1 promoter activity and expression. In conclusion, these results expand our knowledge of the genetic and molecular basis of TGW-GNS trade-offs in wheat. The QTLs and the novel TaGW2-A1 allele are likely useful for the development of cultivars with higher TGW and/or higher GNS.Electronic supplementary materialThe online version of this article (10.1007/s00122-017-3017-y) contains supplementary material, which is available to authorized users.

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Two Florida strawberry cultivars, 'Strawberry Festival' and 'Florida Radiance', were harvested at five fruit developmental stages (white, half red, three-quarter red, full ripe, and overripe) at four harvest dates. A static headspace solid-phase microextraction (SPME) sampling technique coupled with gas chromatography (GC) using pulsed flame photometric detection (PFPD) was employed to measure 16 sulfur volatiles in these strawberries. A total of 7 sulfur volatiles have been previously reported, and 9 are reported for the first time in strawberries. Newly identified sulfur volatiles include methyl thiopropionate, ethyl thiobutanoate, methyl thiohexanoate, methyl (methylthio)acetate, ethyl (methylthio)acetate, methyl 2-(methylthio)butyrate, methyl 3-(methylthio)propionate, ethyl 3-(methylthio)propionate, and methyl thiooctanoate. Identifications were based on matching sulfur peak linear retention indexes (LRIs) of unknowns with authentic standards and gas chromatography-mass spectrometry (GC-MS) data. Concentrations were determined using both internal and external standards. Most sulfur volatiles increased with increasing maturity, with only concentrations of hydrogen sulfide and methanethiol remaining relatively consistent at all five stages. At the white and half red stages, most sulfur volatiles consisted of various alkyl sulfides. At three-quarter red (commercial ripe), full ripe, and overripe stages, the majority of sulfur volatiles consisted of sulfur esters. Most sulfur volatiles increased dramatically between the commercial ripe, full ripe, and overripe stages, increasing as much as 100% between full ripe and overripe. Principal component analysis indicated that sulfur volatiles could be used to distinguish overripe from full ripe and commercial ripe berries.

The volatile composition and sensory attributes of Merlot wines produced from vines under differing levels of water stress, with or without a foliar, kaolin-based particle film, were analyzed by stir bar sorptive extraction-gas chromatography-mass spectrometry (SBSE-GC-MS) and sensory evaluation. Vines were irrigated over consecutive vintages with 100, 70, or 35% of their estimated water requirements (ET(c)), or 35% until color change then 70% until harvest (35-70% ET(c)). Neither of the treatments consistently influenced ester concentrations or their relative amounts, though their concentrations varied from year to year. However, deficit irrigation had an effect on the concentration of terpene alcohols and norisoprenoids. Wines produced from vines under water deficit contained higher amounts of citronellol, nerol, geraniol, and β-damascenone, but linalool and β-ionone were not affected by deficit irrigation. Particle film did not affect volatile composition in the wine. Untrained panelists in 2007 and 2008 distinguished between wines from vines that received 100 or 35% ET(c) and between wines from vines that received 35 or 35-70% ET(c). Trained sensory panelists detected differences among wines for aroma, flavor, taste, and mouthfeel; however, significant interactive effects between particle film application and vine water status hindered interpretation of independent main effects.