Terry Marta I, Ruiz-Hernández Victoria, Águila Diego J, Weiss Julia, Egea-Cortines Marcos
Genética Molecular, Instituto de Biotecnología Vegetal, Universidad Politécnica de Cartagena, Cartagena, Spain.
Department of Biosciences, University of Salzburg, Salzburg, Austria.
Front Plant Sci. 2021 Jan 7;11:540821. doi: 10.3389/fpls.2020.540821. eCollection 2020.
flowers are used as cut flowers and to obtain high quality essential oils for the perfume industry. As a winter crop in the Mediterranean area, it flowers at temperatures ranging between 10 and 15°C during the day and 3-10°C during the night. Here we tested the impact of different light and temperature conditions on scent quality during post-harvest. These two types of thermoperiod and photoperiod. We also used constant darkness and constant temperatures. We found that under conditions of 12:12 Light Dark and 15-5°C, emitted monoterpenes and phenylpropanoids. Increasing the temperature to 20°-10°C in a 12:12 LD cycle caused the loss of cinnamyl acetate and emission of indole. Under constant dark, there was a loss of scent complexity. Constant temperatures of 20°C caused a decrease of scent complexity that was more dramatic at 5°C, when the total number of compounds emitted decreased from thirteen to six. Distance analysis confirmed that 20°C constant temperature causes the most divergent scent profile. We found a set of four volatiles, benzyl acetate, eucalyptol, linalool, and ocimene that display a robust production under differing environmental conditions, while others were consistently dependent on light or thermoperiod. Scent emission changed significantly during the day and between different light and temperature treatments. Under a light:dark cycle and 15-5°C the maximum was detected during the light phase but this peak shifted toward night under 20-10°C. Moreover, under constant darkness the peak occurred at midnight and under constant temperature, at the end of night. Using Machine Learning we found that indole was the volatile with a highest ranking of discrimination followed by D-limonene. Our results indicate that light and temperature regimes play a critical role in scent quality. The richest scent profile is obtained by keeping flowers at 15°-5°C thermoperiod and a 12:12 Light Dark photoperiod.
花朵被用作切花，并用于为香水行业获取高品质香精油。作为地中海地区的冬季作物，它在白天温度介于10至15°C、夜间温度介于3至10°C时开花。在此，我们测试了不同光照和温度条件对采后香气质量的影响。这两种类型的温度周期和光周期。我们还使用了持续黑暗和恒温条件。我们发现，在12:12光暗周期和15 - 5°C条件下，花朵释放单萜和苯丙素类化合物。在12:12光暗周期中将温度提高到20° - 10°C会导致乙酸肉桂酯损失并释放吲哚。在持续黑暗条件下，香气复杂性降低。20°C恒温导致香气复杂性降低，在5°C时更为显著，此时释放的化合物总数从十三种减少到六种。距离分析证实，20°C恒温导致的香气特征差异最大。我们发现一组四种挥发性化合物，乙酸苄酯、桉叶油素、芳樟醇和罗勒烯，它们在不同环境条件下产量稳定，而其他化合物则始终依赖光照或温度周期。香气释放在白天以及不同光照和温度处理之间有显著变化。在光暗周期和15 - 5°C条件下，香气释放最大值在光照阶段检测到，但在20 - 10°C条件下，这个峰值向夜间转移。此外，在持续黑暗条件下，峰值出现在午夜，在恒温条件下，出现在夜间结束时。通过机器学习我们发现，吲哚是判别能力排名最高的挥发性化合物，其次是D - 柠檬烯。我们的结果表明，光照和温度条件对香气质量起着关键作用。通过将花朵保持在15° - 5°C温度周期和12:12光暗光周期下可获得最丰富的香气特征。
