优良香樟苗木快繁技术研究

Cinnamomum camphora is one of important economic tree species in chaina, which has a high commercial value. Planting density of Cinnamomum camphora low forest is the development direction of intensive production and management, and Cinnamomum camphora breeding is vital for the development of camphor oil industy. Asexual reproduction of Cinnamomum camphora existed age effect, namely the rooting ability significantly reduced with the increase of tree age, restricts the development of camphora oil industry. On the bases of this relationship between age and rooting, the induction of rejuvenation might be helpful to achieve better rooting and propagating ability to resolve this contradiction. In this sudty, Cinnamomum camphora from high camphor oil content, biological yield, main composition is used materials to study the effect of the growth of cutting, plant growth regulator IBA and cutting season on rooting. In the meantime, serial subcultures in vitro cause rejuvenation of reproductively mature shoots and hence recover the ability of adventitious rooting ability. Tissue culture combine with cutting technology, finally to establish a low cost, high efficiency in vitro rapid propagation techniques of Cinnamomum camphora.

香樟是我国重要的经济树种之一，具有较高的经济价值。密植矮林是香樟集约化生产和经营发展方向，优良香樟的繁殖对于精油产业的发展至关重要。香樟无性繁殖时存在年龄效应，即生根能力随树龄的增加而显著降低，制约着精油产业的发展。基于树龄与生根的关系，诱导优良香樟返童恢复生根能力是解决这一矛盾的重要途径。本研究选取精油含量、生物产量和主成分比例均高的优良香樟，研究插条发育状况、吲哚丁酸（IBA）、扦插季节对插穗不定根形成的影响；通过连续茎段继代培养诱导成年期优良香樟返童，恢复生根和繁殖能力，建立返童植株扦插采穗圃，结合扦插技术，最终建立低成本、高效率优良香樟苗木快繁技术。

香樟是我国重要的香料树种之一，具有较高的经济价值。但香樟属于无性繁殖难生根、生根慢树种，制约着产业的发展。基于香樟产业苗木市场需求量大，苗木生产能力与市场需求严重脱节。本项目以优良香樟枝条为材料，研究生长调节剂种类及质量浓度、树龄、化学型、插穗长度和粗细、插穗发育状况、插穗采集部位、移栽时间对香樟绿枝扦插生根和成活率的影响。结果表明：吲哚丁酸（IBA）处理香樟插穗生根率最好，其次是双吉尔（GGR），萘乙酸（NAA）较差，3000mg/L是香樟扦插生根适宜质量浓度。树龄、化学型和IBA浓度对樟树扦插生根有显著影响，来自3a生芳樟、柠檬醛樟和异樟生根率高达90%以上，生根能力显著高于成年期材料，童性是香樟生根的一个重要因子；柠檬醛樟、异樟、脑樟和龙脑樟生根能力好于芳樟，芳樟较难诱导生根；3000mg/L IBA是芳樟、脑樟、龙脑樟和异樟最适生根质量浓度，而柠檬醛樟最适生根质量浓度为2000mg/L。插条长度15cm、粗度0.5cm左右，脑樟插穗生根率最高。不同化学型香樟茎段组织培养研究结果表明：脑樟、柠檬醛樟、杂樟茎段组织培养较易成功，芳樟、龙脑樟茎段组织培养较难。外植体的取材时间和取材部位对香樟茎段组织培养影响较大。4-5月份，选取一年生半木质化枝条进行茎段组织培养，75%酒精消毒30s、0.1%升汞消毒5min，2周可诱导腋芽萌芽，而且褐化率低（5%以下）、污染率低（10%左右）。培养基对香樟茎段组织培养有显著影响，MS+1.5mg/L6-BA+0.01NAA是香樟茎段组织培养腋芽萌动适宜培养基，MS+1.0mg/L6-BA+0.5NAA适合于香樟不定芽的分化和增殖，MS+1.5mg/LIBA是香樟组培苗适宜生根培养基。通过茎段继代培养可以恢复香樟的生根能力，香樟组培苗生根率能够达到85%以上。同时，通过转录组测序，初步了解香樟扦插和组培生根的内在调控因子。本项目营建了优良香樟扦插采穗圃，建立了较为完善的香樟扦插和茎段组织培养繁殖技术。