Light modulation of volatile organic compounds from petunia flowers and select fruits

Light intensity, duration, direction, and wavelength are informative to plants. The biochemical circuits that connect specific light wavelengths to expression of specific genes and the metabolic networks they govern have been well defined. However, little emphasis has been placed on how discrete wavelengths of light, alone or in combination, may be applied to manipulate postharvest qualities of high-value horticultural crops. Using narrow-bandwidth LED light we test the hypothesis that discrete light wavelengths can affect the accumulation of volatile compounds known to affect aroma or taste in select flower and fruit products. Volatile benzenoid/phenylpropanoid emission from petunia flowers could be altered with light application. Levels of a key floral volatile, 2-phenylethanol, increased with a red and far-red light treatment. Similar experiments demonstrated that fruit volatile profiles of tomato, strawberry, and blueberry can be manipulated with specific light treatments. These results suggest that compounds affecting sensory qualities of flowers and fruits can be modified by adjustment of ambient light conditions. These findings open new areas of inquiry about how the fragrance and flavor of flowers and fruits may be improved with simple changes in postharvest light conditions.     

桔小实蝇对不同水果及挥发性化合物行为反应的研究

为了解桔小实蝇[Bactrocera dorsalis（Hendel）]对不同水果及挥发性化合物的行为反应,以未交配的和已交配的桔小实蝇雌雄成虫为试虫,采用Y形嗅觉仪测定其对10种果实的反应差异。结果表明,对于同种水果,雌虫比雄虫反应明显,未交配成虫比已交配的成虫反应明显。同时利用触角电位技术测定桔小实蝇对其寄主挥发性物质中常见的10种组分的反应。结果表明,对同种物质,雄成虫交配前触角电位反应值均显著大于交配后触角电位反应值。在交配前雄虫比雌虫的触角电位反应值大,对多数挥发物组分,在交配后雌虫触角电位反应值比雄虫的大。     

Comparison of the Labour Requirement Involved in the Housing of Dairy Cows in Different Housing Systems

Dairy cows are in Denmark either kept in tie-stalls or in loose housing systems. The labour requirement connected to the two systems is very important for dairy farmers who want to adopt a new housing system. The aim of the present investigation was to estimate the labour requirement for the various tasks involved in milk production in different housing systems. The estimation was done by use of models, which were based on detailed work studies carried out among 13 practical stockbreeders. The efficiency of the different housing systems depended on the size of herd. For herd sizes over 100 cows, the total labour requirement was between 27 and 31% lower in loose housing systems than in tie-stall housing systems. However, when the herd sizes were reduced to fewer than 70 dairy cows, the savings obtained on the tasks feeding and cleaning in loose housing systems were counterbalanced by a higher labour requirement on milking.     

几种松树挥发物对松材线虫行为的影响

通过室内生测的方法,研究了几种主要的松树挥发物对松材线虫行为的影响.结果表明,α-异松油烯、β-水芹烯、β-蒎烯抑制松材线虫繁殖,其中α-异松油烯、β-水芹烯抑制力较强,β-蒎烯抑制力较弱,而β-月桂烯、反式-石竹烯、莰烯、异长叶烯和α-蒎烯对线虫繁殖没有影响.β-水芹烯和莰烯具有杀松材线虫活性,β-蒎烯和β-月桂烯增强松材线虫活力,而异长叶烯、α-蒎烯、反式-石竹烯对线虫存活没有影响.β-蒎烯、反式-石竹烯、异长叶烯、莰烯对松材线虫具引诱作用,其中β-蒎烯引诱力最强,反式-石竹烯次之,异长叶烯、莰烯引诱力最弱,而α-蒎烯、β-水芹烯、α-异松油烯和β-月桂烯对线虫无引诱作用.并对几种挥发物在松树抗松材线虫病中的作用进行了讨论.     

Geographical origin and drying methodology may affect the essential oil of Lippia alba (Mill) N.E. Brown

Lippia alba (Mill.) N.E. Brown, the ginger grass, is a medicinal and aromatic plant widely used in Latin America. In this work the effect of the geographical origin and different drying methodologies on L. alba leaves production, essential oil content and composition were evaluated. Field experiments were conducted in three different municipalities (Amargosa, Cruz das Almas and Santo Antônio de Jesus) from Bahia region (Brazil) and two drying methodologies (traditional and artificial with controlled conditions) were assessed. Fresh and dried leaves essential oils were extracted by hydro-distillation and their volatiles were determined by gas chromatography.The geographical origin affected the mass production, essential oil content and both qualitative and quantitative fractions of their composition. Leaves from Cruz das Almas had higher yield in essential oil content. Overall, 26 oil constituents were identified. Carvone, germacrene D and limonene were the main oil constituents. The drying methodologies combined with the geographic origin influenced essential oil composition showing that L. alba constituents were influenced by post-harvest treatments. Some constituents were sensitive to both methods applied, while some enhanced their content like germacrene D.     

芋头挥发性代谢物分析及其品质综合评价

芋头是一种重要的蔬菜兼粮食作物,其营养丰富且药用价值高,然而对于芋头品质性状的评价及分子机理的研究较少。以来源于我国不同地区的18个芋头品种为例,运用生物信息学方法系统评价其外观和营养物质指标,并利用GC-MS气质联用法对挥发性代谢物进行定性和定量分析。结果表明,魁芋芋头的单芋重、干物质和淀粉含量相对高于多子芋。不同芋头品种的品质指标存在明显差异,主成分分析降维方法分析到了4个独立的综合指标,其累计贡献率达82.31%,解释了芋头品质的大部分变异信息。综合得分排名前5名的全部是魁芋。以炭步香芋和花都红芽芋为例的代谢组学分析,共鉴定到76种挥发性代谢物,其中香型中显著上调的代谢物包括1-甲基乙基-萘和4-甲基-6-庚烯-4油化物,说明这2种代谢物很可能与香味生物学功能有关。     

Cultivar influence on virgin olive (Olea europea L.) oil flavor based on aromatic compounds and sensorial profile

Sensory quality is an important property of virgin olive oil and is affected by different volatile and phenolic compounds. Their levels may be influenced by many factors, and one of the most important is the cultivar. Volatiles and phenols were correlated to sensory notes in virgin olive oils from 18 local cultivars in northern Italy assessed for 4 years in the same orchard.     

皂荚和五角枫挥发性物质组成及其对空气微生物的抑制作用

利用动态顶空法收集和TC - TGC - MS (热脱附—气相色谱/质谱联用技术) 分析鉴定了两种绿化树种皂荚和五角枫茎叶的挥发物组分, 采用自然沉降法测定了植物挥发物对空气微生物生长的影响。结果表明: 乙酸- 3 - 己烯酯和乙酸庚酯的含量在皂荚和五角枫中分别为最高的, 癸醛、苯甲醛、trans - 2- 己烯醛、壬醛、1 - 辛醇、正戊醇、3 - 己烯醇为二者共有的组分; 微生物试验表明皂荚和五角枫林地微生物含量明显低于空旷地。乙酸- 3 - 己烯酯、乙酸庚酯、壬醛、己醛、trans - 2 - 己烯醛、1 - 辛醇、正戊醇、3 - 己烯醇8种单体对细菌和真菌有明显的抑制作用, 且乙酸- 3 - 己烯酯的抑菌能力大于乙酸庚酯,因而揭示了皂荚和五角枫林带细菌和真菌少的原因。     

The role of imbibition on seed selection by Harpalus pensylvanicus

Invertebrate weed seed predation is an important component of weed seed loss in agricultural fields. This study investigated the role of seed imbibition on the selection and consumption of the seeds of seven common agricultural weed species by Harpalus pensylvanicus De Geer, a granivorous carabid beetle (Coleoptera: Carabidae) that is found throughout North America. The volatile organic compounds released by ambient dry and imbibed weed seeds were quantified, and Y-tube bioassays were conducted to determine if H. pensylvanicus individuals responded to volatile compounds released from weed seeds. H. pensylvanicus individuals were found to consume higher masses of seeds for each weed species examined in imbibed versus ambient dry trials (P < 0.05). Larger seeded species had the greatest increase in mass consumption between dry seed and imbibed seed trials. The seeds from the seven weed species examined released carbon dioxide and ethylene when ambient dry and imbibed, but H. pensylvanicus adults were only able to detect weed seeds through olfaction when volatile release was highest as a result of imbibition. These results demonstrate that seed imbibition is important in determining seed detection and consumption by invertebrates and may affect seed banks in agricultural fields.     

iTRAQ-based quantitative proteomics analysis reveals the molecular mechanism of controlled atmosphere storage for Tibetan hull-less barley (Hordeum vulgare L) preservation

Controlled atmosphere storage (CAS) is an effective method for cereal grain preservation, but its mechanism is yet to be completely elucidated. In this study, the molecular mechanism of CAS was evaluated for Tibetan hull-less barley preservation using iTRAQ quantitative proteomics, Western blot, and physicochemical and individual volatiles analyses. In barley stored at 25 °C, compared with non-controlled atmosphere storage (NCAS), CAS altered the expression of 116 proteins by > 2.0 fold. Among these proteins, 82 downregulated proteins were mainly involved in carbon metabolism, protein and amino acid metabolism, and lipid and fatty acid degradation. Physicochemical analyses suggest that CAS could reduce the severity of abiotic stress. Bioinformatic and molecular biology analyses reveal that CAS could decrease the rates of carbon metabolism, protein and amino acid metabolism, and lipid and fatty acid degradation by downregulating some key proteins (Beta-amylase, 6-phosphofructokinase 1, isocitrate dehydrogenase, glutamate decarboxylase, 1-pyrroline-5-carboxylate dehydrogenase, seryl-tRNA synthetase, leucyl-tRNA synthetase, aspartyl-tRNA synthetase, aldehyde dehydrogenase (NAD+), and alcohol dehydrogenase), accompanied by significant reductions in oxidative dehydrogenation reactions (p < 0.05). Together, a favorable environment provided by CAS ultimately mitigated physiological abnormalities, nutrient and energy consumption, and flavor deterioration in the barley. The proteomics analysis results were confirmed by Western blot, and physicochemical and individual volatiles analyses.