Procedure for artificial cross pollination in clove (Syzygium aromaticum)

Summary A technique for artificial cross pollination in clove is described. This involves emasculating flowers two days before anthesis, and pollinating four days later. Following this procedure a seed set of approximately 25% can be expected.     

丁香的特征特性与栽培技术

阐述了丁香的特征特性,通过介绍丁香繁殖方法及其栽培技术,以期为丁香的栽培提供技术支持。     

肖蒲桃叶绿体基因组结构特征及系统发育关系

【目的】肖蒲桃(Syzygium acuminatissimum)是我国南方高价值的硬木树种之一,适宜作为行道树或园景树。研究揭示肖蒲桃叶绿体基因组的结构特征及系统发育关系,对蒲桃属甚至桃金娘科的分类学研究具有重要意义。【方法】使用CTAB法提取肖蒲桃叶片基因组DNA。利用Illumina HiSeq X TEN平台进行高通量测序,在SPAdes v3.13.0上组装叶绿体基因组,并通过GeSeq注释肖蒲桃的完整叶绿体基因组。分析了肖蒲桃叶绿体基因组的结构特征、序列特征及系统发育关系。【结果】肖蒲桃完整的叶绿体基因组长度为159 352 bp,共有109个基因,包括78个蛋白质编码基因、27个tRNA基因和4个r RNA基因,其中17个基因具有内含子;检测到21 379个密码子,其中丝氨酸密码子最丰富、蛋氨酸密码子最匮乏;检测到47个RNA可编辑位点,其中ndhB基因最多(10个);检测到48个长片段重复序列,其中18个正向重复、6个反向重复、22个回文重复和2个互补重复;检测到230个简单重复序列,其中绝大多数为单核苷酸(205个)。基因组比较分析结果表明,4个蒲桃属植物的IR边界有较小差异,核苷酸多样性高于0.015的区间有7个。系统发育分析结果表明,肖蒲桃与丁香蒲桃(S. aromaticum)关系密切。【结论】研究结果有助于开展后续的蒲桃属系统发育研究和物种鉴定工作。     

莲雾插穗与其母体植株叶片光合特性比较研究

在种苗智能化快繁系统调控下,探讨生根过程中莲雾插穗叶片与其母体植株叶片光合特性的差异。结果表明,扦插前中期插穗叶片的净光合速率高于母体植株,插穗叶片PSII有效光化学量子产量（YIELD ）始终保持在离体时的较高水平,插穗生根后叶片光合电子传递速率（ETR）均高于母体植株,反映了在种苗智能化快繁系统调控下,莲雾插穗叶片的光合能力不低于其母体植株,仍保持刚离体时的较高水平,插穗依靠叶片光合作用为其生根提供物质和能量。     

莲雾采前管理及采后商品化处理技术

果实的采前管理与果实的品质和耐贮性关系密切.介绍了莲雾结果树的肥水管理、花果管理、病虫害防治等采前管理技术,同时介绍了莲雾商品生产的采后处理技术,包括果实的适时采收、分级、预冷、保鲜处理等重要环节,为莲雾的商品化生产提供相应的标准化操作规范.     

莲雾智能化快繁插穗、基质和促根剂类型选择研究

在种苗智能化系统调控下探讨莲雾插穗、基质、促根剂等3 种因素对扦插生根的影响,结果表明：木质化及半木质化枝梢带叶插穗其成活率高、根系性状好于落叶枝梢插穗;泥炭土基质的插穗根条数显著地高于沙基质,根生长量亦明显地高于沙及珍珠岩基质;IBA、NAA、IAA 等3 种促根剂中以IBA 种类效果较好,其中IBA500×10^-6处理对插穗成活率提高及根条数增加有明显作用.     

红鳞蒲桃开花物候特性研究

对红鳞蒲桃种群的花期物候，单株、单个花序、单花的开花动态进行系统的观测研究，详细测量并记录花部构件，同时调查红鳞蒲桃种群的同花期植物。结果表明：红鳞蒲桃种群的花期物候为8月1日～9月15日（2008年），持续时间46d；单株花期从23d到33d不等；单花序的花期情况较为复杂，总体表现为花朵数越多，该花序持续时间越长，但也有个别情况出现，在开花中期花序持续时间长，开花后期花序持续时间最短，开花前期花序持续时间介于两者之间；在整个种群花期内单花平均开花时间约5．2d，种群开花前期单花的持续时间约为6．7d，开花中期约为4．7d，末花期约为4．3d，种群开花前期单花的持续时间显著大于种群中后期的持续时间。红鳞蒲桃种群的同花期植物隶属于16科21属22种。     

Epidemiology of a Neotropical rust (Puccinia psidii): periodical analysis of the temporal progress in a perennial host (Syzygium jambos)

The epidemiology of the Neotropical rust caused by Puccinia psidii in the Indian Myrtaceae Syzygium jambos (rose apple) was investigated in central Brazil. Disease severities recorded during a 12-month period were fitted by a Fourier curve with three cyclic components or harmonics. The first, second and third harmonics accounted for 49·6, 25·9, and 1·5% of total disease measured, respectively. A highly significant linear correlation was observed between the first harmonic and the accumulated number of days having at least 6 h wetness, or a minimum of 90% relative humidity, combined with temperatures that ranged from 18 to 20°C. No significant correlation was observed between the second and third harmonics and the weather variables evaluated. Rose apple trees showed a flush of growth with new susceptible host tissue during the evaluation period, with two major outbreaks of rust of variable intensity. Host growth was fitted by a Fourier curve with two significant harmonics. The first and second harmonics accounted for 37·5 and 22·1% of total host growth measured, respectively. A highly significant negative linear correlation was observed between the first harmonic and daily maximum and minimum temperatures, rainfall, and duration of the light period. Inoculum availability was not a limiting factor for disease progress since urediniospores were present during most of the period studied. A major peak in numbers of rust spores followed the main peak of disease severity. Thus, rust epidemics on rose apple in central Brazil were shown to depend on the duration of leaf wetness in the dark, and also on night-time temperatures during that same wetness period. This study is the first example of a periodical analysis of an epidemic in a perennial crop.     

Toxicity nanoinsecticide based on clove essential oil against Tribolium castaneum (Herbst)

This study aimed to characterize nanoparticles loaded with clove (Syzygium aromaticum) essential oil-based polyethylene glycol (PEG) and to know their insecticidal activity against red flour beetle (Tribolium castaneum). The nanoparticles have irregular shapes in good dispersion. The nanoformulation could not enhance clove oil contact toxicity to T. castaneum, but could protect the oil from degradation and evaporation while simultaneously allowing sustained release, as indicated by the continued high toxicity for 16 weeks of storage.     

Structure–activity relationships of eugenol derivatives against Aedes aegypti (Diptera: Culicidae) larvae

BACKGROUND: Dengue fever is a severe public health problem for several countries. In order to find effective larvicides to aid control programs, the structure‐activity relationships of eugenol derivatives against Aedes aegypti (Diptera: Culicidae) larvae were evaluated. Additionally, the composition and larvicidal activity of Syzygium aromaticum essential oil was assessed. RESULTS: Four compounds representing 99.05% of S. aromaticum essential oil have been identified. The essential oil was active against Ae. aegypti larvae (LC₅₀ = 62.3 and 77.0 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity of eugenol, the major compound of the essential oil, was further evaluated (LC₅₀ = 93.3 and 71.9 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity and structure‐activity relationships of synthetic derivatives of eugenol were also assessed. The larvicidal activity of the derivatives varied between 62.3 and 1614.9 ppm. Oxidation of eugenol allylic bond to a primary alcohol and removal of the phenolic proton resulted in decreased potency. However, oxidation of the same double bond in 1‐benzoate‐2‐methoxy‐4‐(2‐propen‐1‐yl)‐phenol resulted in increased potency. CONCLUSION: Structural characteristics were identified that may contribute to the understanding of the larvicidal activity of phenylpropanoids. The present approach may help future work in the search for larvicidal compounds. Copyright © 2012 Society of Chemical Industry