【作者】 刘小金；

【导师】 徐大平；

【作者基本信息】 中国林业科学研究院 ， 森林培育， 2012， 博士

【摘要】 檀香（Santalum album）是我国华南地区近几年大力推广种植的重要珍贵经济树种之一，它的主要经济价值在于其具芳香气味的心材和从心材中提取的檀香精油。檀香心材的形成（俗称“结香”）是一个非常复杂的生理生化过程，自然生长条件下，印度地区一般需10~13年才陆续开始结香。尽管檀香已在我国成功引种，早期的生长表现也良好，但我们对檀香人工林的心材形成情况、心材精油含量、精油成分的分布规律以及精油的质量等了解得还非常有限，很有必要进行深入研究，因为檀香的经济价值主要取决于心材的数量、心材的精油含量、精油成分组成以及精油的质量等。本论文以海南尖峰岭21年生檀香人工林为成龄檀香，分析其心材形成、精油含量及成分分布情况，为进一步了解檀香心材形成过程中一些精油成分的变化规律提供奠定基础；同时，采用抽样调查的研究方法，分析了集约化种植的6年生檀香人工林的心材形成情况，并对我国大规模发展檀香人工林的前景作一初步评估；另外，为了缩短檀香自然结香的时间，以6年生未形成心材的幼龄檀香为研究对象，采用树干填充气体、树干注射生长调节剂和树干接种真菌等方法，开展了促成心材形成的试验。主要的研究结果如下：（1）海南尖峰岭21年生檀香人工林均已自然结香，平均心材比例为38.01%，平均精油含量为5.52%，从心材提取的檀香精油中α-檀香醇含量和β-檀香醇含量均达到了国际檀香木油的质量标准。（2）檀香树干的东、南、西、北方向和中部（髓心）之间的精油含量差异不显著（p=0.583），但髓、心材中部、心材外部和边材的精油含量之间差异极显著（p<<0.001）；边材的精油含量显著的低于心材，平均含油量为1.61%，在成分组成上却显著多于心材（p<<0.001），多出的主要成分为饱和烃、饱和醛以及含十八个碳原子的酸类物质等；心材的不同位置之间精油含量和成分组成的差异均不显著。（3）檀香心材和边材的总檀香烯含量（p=0.992）和倍半萜烯含量（p=0.982）的差异不显著，但总檀香醇含量（p<<0.001）和倍半萜烯醇含量（p<<0.001）的差异均显著。心材的檀香醇类物质和倍半萜烯醇类物质含量远远高于边材，但檀油醇含量却显著的低于边材（p<<0.001）。（4）檀香人工林的集约化种植在我国南方地区早期的生长和结香表现良好，6龄就零星开始结香了，但结香的比例较低（15%~20%），心材的精油含量也较低（0.66%~1.76%）；幼龄檀香心材精油的成分组成和成龄檀香精油的组成基本一致，但α-檀香醇和β-檀香醇的含量均比较低，平均相对含量为20.19%和10.14%，没有达到檀香木油的国际质量标准。（5）树干填充外源气体能促成幼龄檀香形成心材，促成心材的面积大小差异显著（p<<0.001），各处理促成的檀香心材在树干分布面积的统计学大小顺序为：氮气处理>二氧化碳处理>乙烯处理=机械损伤处理；乙烯处理促成的檀香心材中精油含量最高，平均含量高达17.11%，超出檀香的正常含油量范围，也显著地高于其它各处理的精油含量（p=0.001），但精油中α-檀香醇和β-檀香醇的含量却很低，平均相对含量为31.05%和12.67%；精油成分分析结果表明，精油中杂质较多，多为一些酚类等抽提物；各气体处理中，二氧化碳处理促成的檀香心材其精油中α-檀香醇和β-檀香醇的相对含量最高，平均相对含量分别为41.09%和18.91%，并且符合檀香木油的国际质量标准，这意味着二氧化碳可能在促成檀香心材的形成中具有重要作用。（6）树干注射生长调节剂能促成幼龄檀香形成心材，但各种不同的生长调节剂以及相应的浓度对促成的檀香心材面积的大小影响不显著（p=0.457）；0.3%的乙烯利处理对幼龄檀香叶片的光系统II功能反应中心造成了较大的损害，降低了光能的利用效率，从而使叶片的净光合速率显著降低（p<<0.001）；0.6%的6-苄氨基腺嘌呤处理促成的檀香心材中精油含量最多，平均含量为9.34%，显著地高于其它各处理（p<<0.001），其次是0.3%的乙烯利处理和0.3%的茉莉酸处理，平均精油含量均为5.33%，0.15%的甲基紫精处理促成的檀香心材中精油含量最低，平均含量仅为2.54%。（7）树干注入6-苄氨基腺嘌呤（含0.3%和0.6%两种不同的浓度）、0.3%的乙烯利、0.3%的茉莉酸和0.3%的甲基紫精促成的檀香心材中精油的α-檀香醇和β-檀香醇均达到了檀香木油的国际质量标准，意味着6-苄氨基腺嘌呤在调控檀香心材的形成中发挥着关键作用。（8）树干接种真菌能促成幼龄檀香形成心材，并且不同的菌种对促成的檀香心材面积的影响差异达显著水平（p<<0.001），各菌种处理促成的心材面积的统计学大小顺序为：柑橘葡萄座腔菌>镰孢菌属一种真菌>胶孢炭疽菌=Khuskia属一种真菌=对照；Khuskia属一种真菌处理促成的檀香心材精油含量最高，平均含量为7.74%，显著的高于其它各菌种处理（p=0.032），但各真菌处理促成的檀香心材精油中杂质较多，多为一些未分离或未鉴定的化合物；接种各种真菌促成的檀香心材，其精油的α-檀香醇和β-檀香醇含量均较低，都没有达到檀香木油的国际质量标准，因此，接种真菌用于促成幼龄檀香形成心材在很大程度上不理想。（9）各种促心材形成的处理（填充气体、注射化学物质和接种真菌等）促成的檀香心材在含水量和基本密度等属性的差异均较小，表明檀香心材的属性受外界的影响较小，基本保持在一个相对稳定的范围内。（10）檀香心材的形成和衰老没有直接的联系，但和内部激素的不平衡有较大的关系。更多还原

【Abstract】 Sandal (Santalum album) or east Indian sandalwood, one of the most important economictree species promoted for large area planting in southern China in recent years, is highlyvaluable for its aromatic heartwood and the essential oil distilled from its fragrant heartwood.Heartwood formation is a very complicated physio-biochemical process in sandal, and it willtake10~13years to form heartwood generally in India. Although sandal has introduced intoChina more than40years, and early growth is pretty well, information on heartwood formation,oil content, oil composition, oil distribution, ingredient distribution as well as oil quality is veryscare, and need a further study, because the economic value of sandal will depend largely onthe volume of heartwood, essential oil content, oil composition and oil quality.This dissertation strives to study the heartwood presence, essential oil content, essentialoil composition as well as ingredient distribution of sandal based on a21-year old maturesandal plantation in Jianfengling, Hainan island. Meanwhile, the growth, heartwood presence,oil content as well as oil composition of6-year old young sandal trees which planted inlarge-scale in Guangdong province were also studied through a sample plot survey method. Inaddition, a series of experiments including gas filling, chemical injection as well as fungiinoculation were conducted in order to accelerate heartwood formation in young sandals.Major conclusions are summarized as follows:（1）21-year old sandal plantation in Jianfengling, Hainan island have formed heartwoodnaturally with an average heartwood proportion of38.01%, an average oil content of5.52%,both content of α-santalol and β-santalol extracted from heartwood have achieved the currentISO standard for sandal oil.（2）No significant differences of oil content (p=0.583) was found among different parts ofheartwood (part referred to east, south, west, north and center or pith), but their was significantdifferences (p<<0.001) between different locations (location referred to sapwood, outerheartwood, central heartwood and center or pith). Oil extracted from sapwood was lower than that extracted from heartwood, but consisted of more ingredients than those in heartwood, mostof which were saturated hydrocarbon, saturated aldehyde and eighteen-carbon skeleton acid.Average oil content of sapwood was1.61%.（3）No significant differences of total santalene content (p=0.992) and sesquiterpenehydrocarbon content (p=0.982) were found between sapwood and heartwood, but thedifferences on total santalol content (p<<0.001) and sesquiterpene alcohol content (p<<0.001)were great. Santalols and sesquiterpene alcohols isolated from heartwood were higher incontent than those isolated from sapwood, while teresantalol content in heartwood was lowerthan those in sapwood (p<<0.001).（4）Large-scale sandal plantations had good growth in southern China, about15~20%ofthe individuals started to form heartwood naturally as early as6-year old, but the oil content inthese young sandals was low, which ranged from0.66%to1.76%. Essential oil compositionwas similar with that extracted from mature sandals, but the content of α-santalol andβ-santalol were low, which account for20.19%and10.14%in average respectively, the qualityof oil did not meet with the current ISO standard for sandal oil.（5）Heartwood in young sandal could be induced by stem gas filling, but the amount ofheartwood induced by different gas treatments was significantly different (p<<0.001). The areaor amount of induced heartwood above/below the drill hole was as the following order:nitrogen> carbon dioxide> ethylene=wounding. Treatment with ethylene had the highest oilcontent of17.11%in average among all treatments (p=0.001), which was far beyond thenormal oil content of sandal, but α-santalol content and β-santalol content were relative low,only31.05%and12.67%in average respectively；Ingredient analysis showed that essential oilextracted from heartwood induced by ethylene contained some polyphenols, extractives andother non-santalol substances. Treatment with carbon dioxide had the highest content ofα-santalol and β-santalol, which were41.09%and18.91%in average respectively, and oilquality met with the current ISO standard for sandal oil, which means that carbon dioxide mayplay an important role in induction heartwood formation of sandal. （6）Heartwood in young sandal could be induced by stem injection of chemicals, and nostatistically differences were found in term of heartwood amount (p=0.457) between differentchemical treatments and the corresponding concentrations; Stem injection of0.3%ethrel hadcaused great damage on PSII of young sandals, as a result, light use efficiency was reducedsubsequently, and net photosynthesis rate was decreased significantly (p<<0.001); Steminjection of0.6%benzyladenine had the highest oil content in the induced heartwood (9.34%in average) among all treatments (p<<0.001), followed by0.3%ethrel and0.3%jasmonic acid(both were5.33%in average); treatment with0.15%paraquat had the least oil content amongall treatments, only2.54%in average.（7）Oil quality of heartwood induced by low concentration of ethrel (0.3%), lowconcentration of jasmonic acid (0.3%) and high concentration of paraquat (0.3%) met with theISO standard for sandal oil, but both concentrations of benzyladenine (low referred to0.3%and high referred to0.6%) caused young sandals to form qualified oils which meet with thecurrent ISO standard for sandal oil, this indicated that benzyladenine could play a key roleduring heartwood formation of sandal.（8）Stem inoculation of fungi could induce heartwood formation in young sandals, and thearea or amount of heartwood induced by different fungis was statistically different (p<<0.001).The area or amount of induced heartwood above/below the inoculation drill was as thefollowing order: Botryosphaeria rhodina> Fusarium spp> Colletotrichum gloeosporioides>Khuskia spp=C.K. Inoculation of Khuskia spp got the highest oil content among all treatments(p=0.032), which are7.74%in average. Many non-santalols and unidentified or unisolatedsubstances were found in essential oil which extracted from heartwood induced by fungi, as aresult, α-santalol content and β-santalol content were relative low so that oil quality could notmeet with the current ISO standard for sandal oil. Therefore, stem inoculation of fungi ininduction heartwood formation of young sandals was not so practical.（9）Differences on water content and basic density of sandal heartwood induced bydifferent treatments (include gas filling, chemical injection and fungi inoculation) were not significant, which indicated that some properties of sandal heartwood were unsesceptible totreatments or stresses, and maintained in a cetrain range.（10）It seems that sandal heartwood formation and senescence were two independentprocesses with little connection, but harmone imbalance could have great influences on forcingheartwood formation of young sandal.更多还原