喜树暗斑螟生物学特性及防治

喜树暗斑螟Euzophera sp．是国内危害喜树Camptotheca acuminma Decn．的新害虫，在江西安福1a发生4代，以蛹在寄主树皮缝和枯卷叶内越冬。越冬代翌年4月上旬开始羽化并产卵。各代幼虫发生期依次为：4月中旬至6月中旬、5月下旬至7月下旬、7月上旬至9月上旬、8月中旬至10月中旬。在幼虫始盛期用40％氧化乐果乳油与水1：1的混合液涂环1周(宽为直径的1／3)，对当代防治效果达90％以上。     

Nitrate reductase activity and its diurnal variation rhythm for Camptotheca acuminata seedlings

Nitrate reductase activity (NRA) in different plant organs and leaves in different positions of Camptotheca acuminata seedlings was determined by an In vivo assay, the diurnal variation rhythm of NRA in leaves of different positions was observed,and the correlations between leaf NRA, leaf area and lamina mass per unit area (LMA) were also examined. The results showed that NRA in the leaf was significantly highest, compared with that in other organs such as roots, stems and leaves. In this experiment, the 10 leaves were selected from the apex to the base of the seedlings in order. The different NRA occurred obviously in leaves of different positions of C. acuminata seedlings from the apex to the base, and NRA was higher in the 4th-6th leaves.The diurnal change rhythm of leaf NRA showed a one peak curve, and maximum NRA value appeared at about midday (at 12:30 or so). No obvious correlations between NRA and leaf area or lamina mass per unit area were observed. This study offered scientific foundation for the further research on nitrogen metabolism of C. acuminata.     

豫南丘岗地区喜树栽培技术

喜树为紫树科(珙桐科),国家二级保护植物,是豫南地区主要造林树种.5年生喜树高可达6.5 m、胸径7.6 cm;10年生树木高可达10.2 m、胸径16 cm.近几年豫南丘岗地区利用退耕还林大力种植喜树,不仅美化了环境,而且还能增加农民经济收入,成为调整农业产业结构,促进农民脱贫致富奔小康的重要之路.     

喜树硬枝扦插育苗技术研究

为满足市场对喜树苗木的需求,解决喜树硬枝扦插成活率较低的难题,于2013~2014年采集喜树1年生硬枝作插穗,分别用100mg/L、200mg/L和300mg/L的IBA溶液浸泡插穗下端1h或2h,扦插于塑料拱棚中。以300mg/L IBA溶液浸泡1h,100mg/L IBA溶液浸泡2h处理后生根率为82.5%~88.8%。单株生根9.9~10.8条,扦插苗生根成活率达87.9%~90.1%,扦插当年苗生长良好。     

13个广西喜树种源的喜树碱含量分析

以13个广西喜树(Camptotheca acuminata)种源的嫩叶为试材,研究不同种源对喜树碱含量的影响。结果表明,不同种源的喜树碱含量有极显著差异,不同土壤类型和海拔种源间的喜树碱含量有显著或极显著影响。13个广西喜树种源的喜树碱含量从高到低排序为德保田林金秀隆林德峨兴安西林天峨永福凌云东兰隆林新州南丹灵川。德保、田林、金秀喜树种源是优良种源。     

喜树种子萌发更新潜力初探

在贵阳地区，喜树各部位的种子成熟时间有一定差异，各部位于１０月上旬开始陆续进入生理成熟期，１０月下旬各部位的种子均已达到生理成熟。不同个体、同一个体的不同部位以及离母体植株不同扩散距离处的种子，其萌发更新潜力不同。不同个体的发芽率为：大树（３４．１％）〉中树（３３．５％）枯梢树（３１．６％）〉小树（３０．１％）。同一个体而言、中树和大树的中部枝条上的种子发芽率最高，枯梢树上部枝条的种子发芽率最高，     

干旱胁迫与抗蒸腾剂对喜树几项生理指标及喜树碱含量的影响

经过12d的干旱胁迫，喜树叶内Fpro和MDA含量分别升高了46．7％和19．06％，是同期对照的138．93％的117％；Pn降为负值；Tr和Sc显著下降，降低幅度分别为58．28％和75％；且随着胁迫时间的延长，变化幅度逐步增大。抗蒸腾剂可有效地缓解胁迫对喜树的不良影响。短期干旱胁迫可使叶内喜树碱的含量明显提高，在生产中可由此而提高喜树碱的产量。