Exploration of Floral Volatile Organic Compounds in Six Typical <i>Lycoris</i> taxa by GC-MS

<i>Lycoris</i>, which is known as the &#8216;Chinese tulip,&#8217; has diverse flower colors and shapes, and some species have a delicate fragrance. However, limited studies have reported the volatile organic compounds (VOCs) of <i>Lycoris</i>. In this study, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was used to analyze the floral VOCs of six typical <i>Lycoris</i> taxa. Thirty-two VOCs were identified, including terpenoids, alcohols, esters, aldehydes, ketones, and phenols. The aldehyde and terpenoid contents in <i>Lycoris aurea</i> were higher than in the other taxa, and the ester and alcohol contents in <i>L. sprengeri</i> were the highest compared to all taxa tested. Compared with other species and cultivars, <i>L. longituba</i> and <i>L. longituba</i> var. <i>flava</i> were the two most scented taxa and the VOCs were dominated by terpenoids and esters. <i>L. radiate</i> and <i>L. chinensis</i> were two unscented taxa and, accordingly, the VOC content was weak. A partial least squares discriminate analysis of the floral VOCs among the six <i>Lycoris</i> taxa showed that the six taxa could be successfully separated. Moreover, the VOCs of <i>L. longituba</i> and <i>L. longituba</i> var. <i>flava</i> clustered together. &#946;-Ocimene was verified as the most important aroma compound, as determined via the calculation of the variable importance in projection values and significance analysis. &#946;-Ocimene and its trans isomer, <i>trans</i>-&#946;-ocimene, had a high relative content in <i>L. longituba, L. longituba</i> var. <i>flava, L. aurea</i>, and <i>L. chinensis</i> but were not detected in <i>L. sprengeri</i> and <i>L. radiata.</i> These results indicate that floral VOCs might be selected during the evolutional processes of <i>Lycoris</i>, and &#946;-ocimene could be the most typical VOC among the different <i>Lycoris</i> taxa.