对广西、江西、广东、云南、湖北和四川的48株野生柠檬醛型香樟〔Cinnamomum camphora （Linn.） Presl〕、黄樟〔C. parthenoxylon （Jack） Meisn.〕、细毛樟（C. tenuipilum Kosterm.）和猴樟（C. bodinieri Lévl.）进行调查；采用气相色谱-质谱联用技术对样株叶片精油中的柠檬醛相对含量进行检测；在此基础上，对供试样株叶片精油得率和柠檬醛相对含量进行比较，并筛选优良单株。结果表明：供试样株叶片精油得率和柠檬醛相对含量的均值分别为1.35%和47.62%，变异系数分别为58.78%和30.38%。方差分析结果表明：样株间的叶片精油得率存在显著（P<0.05）差异。不同种类叶片精油得率均值从高到低依次为香樟、黄樟、猴樟、细毛樟，而柠檬醛相对含量均值从高到低依次为细毛樟、黄樟、猴樟、香樟；不同省（自治区）叶片精油得率均值从高到低依次为广东、广西、江西、四川、湖北、云南，而柠檬醛相对含量从高到低依次为广东、云南、江西、湖北、广西、四川。依据叶片精油得率高于1.35%及柠檬醛相对含量高于47.62%的标准，选出14株初选优株；依据选优指标大于121.01进行二次筛选，最终选出8株优良单株（即2株香樟和6株黄樟），包括1株一级优良单株、1株三级优良单株和6株四级优良单株，其中，一级优良单株（采自广东紫金的黄樟）的叶片精油得率为3.64%，柠檬醛相对含量为51.12%。研究结果显示：柠檬醛型樟组植物的叶片精油得率和柠檬醛相对含量均存在种类间、个体间和产地间差异；香樟和黄樟的三分之一为优良单株。

In present study， 48 wild individuals of citral chemotype of Cinnamomum camphora （Linn.） Presl， C. parthenoxylon （Jack） Meisn.， C. tenuipilum Kosterm.， and C. bodinieri Lévl. from Guangxi， Jiangxi， Guangdong， Yunnan， Hubei， and Sichuan were investigated. Citral relative content in essential oil from leaves of sampling plants was detected by using gas chromatographymass spectrometry technology. On this basis， leaf essential oil yield and citral relative content of test sampling plants were compared and superior individuals were screened. The results show that the averages of leaf essential oil yield and citral relative content are 1.35% and 47.62%， respectively， their coefficients of variation are 58.78% and 30.38%， respectively. The results of variance analysis show that there is a significant （P<0.05） difference in leaf essential oil yield among sampling plants. For species comparison， the average of leaf essential oil yield from high to low is C. camphora， C. parthenoxylon， C. bodinieri， C. tenuipilum， while the average of citral relative content from high to low is C. tenuipilum， C. parthenoxylon， C. bodinieri， C. camphora. For region comparison， the average of leaf essential oil yield from high to low is Guangdong， Guangxi， Jiangxi， Sichuan， Hubei， Yunnan， whereas the average of citral relative content from high to low is Guangdong， Yunnan， Jiangxi， Hubei， Guangxi， Sichuan. In this study， the preliminary criteria of superior individual screening are leaf essential oil yield higher than 1.35% and citral relative content higher than 47.62%. Accordingly， 14 individuals are picked out into secondary qualification. As the result of selection index greater than 121.01， 8 superiors individuals belonging to 2 individuals of C. camphora and 6 individuals of C. parthenoxylon are screened， which include 1 first grade superior individual， 1 third grade superior individual， and 6 fourth grade superior individuals. The first grade superior individual （C. parthenoxylon collected from Zijin of Guangdong） shows 3.64% leaf essential oil yield as well as 51.12% citral relative content. The result shows that leaf essential oil yield and citral relative content present difference among species， individuals， and localities. One-third proportion of C. camphora and C. parthenoxylon are superior individuals.