植物激素对大岩桐愈伤组织诱导和芽分化增殖的影响

以大岩桐(Sinningia specioca)的幼嫩茎、叶片为外植体,通过正交实验的方法探讨不同浓度和比例的植物激素对愈伤组织诱导和芽分化增殖的影响。实验结果表明:大岩桐愈伤组织的形成最佳激素组合为2,4二-氯苯氧乙酸2.0 mg/L 6苄-基嘌呤0.1 mg/L 萘乙酸0.3 mg/L;芽分化的最佳激素组合为6苄-基嘌呤0.5mg/L 萘乙酸0.1 mg/L。     

Plant regeneration and protoplast culture of Browollia speciosa

Explants from hypcotyls and cotyledons of Browalia speciosa were shown to regenerate plantlets.Protoplasts were isolated from etiolated cotyledon material, and, although callus was readily obtained, plantlet regeneration was not observed using numerous hormone regimes.Abbreviations M Mannitol - 2,4-D Dichlorophenoxyacetic acid - NAA Naphthalene-acetic acid - BAP Benzylaminopurine - MS medium Murashige and Skoog (1962) medium - UM medium Uchimiya and Murashige (1974) medium - COT cotyledon - SH shoot - R root     

丝棉木的引种及繁殖

丝棉木(Chorisia speciosa St.)是原产南美洲热带及亚热带地区的木棉科植物。落叶乔木,树干挺拔,树形优美,花期长,花朵大而绚丽,美国、秘鲁等国广泛用于道路及庭园绿化。一般认为只能通过种子繁殖。70年代末至80年代初我国广东和海南地区曾少量试种,表明植株长势及观赏效果甚佳。但一直不能自然结实,因而难     

大叶紫薇叶的化学成分研究

从大叶紫薇叶子中分离鉴定了4个化合物,分别为23-羟基熊果酸(1)、alphitolic acid(2)、熊果酸(3)和β-谷甾醇(4),这4个化合物均为首次从该植物中分离得到。     

Water relations of tropical dry forest flowers: pathways for water entry and the role of extracellular polysaccharides

Many trees in tropical dry forests flower during the dry season when evaporative demand is high and soil water levels are low. In this study the factors influencing the water balance of flowers from three species of dry forest trees were examined. Flowers had greater mucilage contents than leaves, high intrinsic and absolute capacitances, long time constants for water exchange and high transfer resistances. Flower water potentials were higher than in leaves and did not fluctuate over the lifespan of the flower. Flower water content also remained constant even though evaporation rates were high, suggesting that water was being supplied from the stem. In two of the species, the water potential gradient between flowers and leaves was opposite to that necessary for water transport from stem to flowers through the xylem, and it was therefore hypothesized that water may enter the flower through the phloem. Calculations showed that nectar production in these flowers could drive a sink of sufficient magnitude to allow water input via the phloem equal to water lost from the flower to the atmosphere.     

Comparative larvicidal activity of essential oils from three medicinal plants against Aedes aegypti L

This work aimed at comparing larvicidal activity of essential oils extracted from the dried leaves of Alpinia speciosa, Cymbopogon citratus, and Rosmarinus officinalis against Ae. aegypti larvae. The larvae were observed for 4 h and at 24 h according to a completely randomized design with three replications and the following concentrations [μl/ml]: 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, and controls were distilled water, and commercial standard citral, camphor, eucalyptol, α‐pinene, and β‐myrcene. The essential oil of C. citratus had the lowest LC₅₀ (0.28) and LC₉₀ (0.56) values, followed by that of A. speciosa (0.94 and 1.2, resp.) and of R. officinalis (1.18 and 1.67, resp.), and only the commercial standards citral and α‐pinene were larvicidal.     

大花紫薇大小孢子的发生及雌雄配子体的发育

用石蜡切片法对不同发育时期的大花紫薇（Lagerstroemia speciosa）花朵进行解剖研究,探讨其大小孢子的发生及雌雄配子体的发育过程,结果发现：大花紫薇花药4室,花药壁由表皮、药室内壁、中层和腺质绒毡层构成,发育类型为双子叶型;小孢子四分体多为四面体型,偶见十字交叉型,胞质分裂为同时型;成熟花粉粒属于2-细胞型,具3孔沟,偶见败育现象;大花紫薇雌蕊具6~7心皮,子房6~7室,每室具多枚倒生胚珠,双珠被,厚珠心,大孢子4分体呈直线排列,近合点端大孢子发育为蓼型胚囊,成熟胚囊为7细胞8核。花粉及胚囊发育多数正常,大花紫薇可以作为优良的杂交母本;同时可以根据开花物候不同阶段花的形态特征,初步判断大花紫薇大、小孢子发生和雌、雄配子体的发育进程。     

A comprehensive multi-directional exploration of phytochemicals and bioactivities of flower extracts from Delonix regia (Bojer ex Hook.) Raf., Cassia fistula L. and Lagerstroemia speciosa L.

Delonix regia (Bojer ex Hook.) Raf., Cassia fistula L. and Lagerstroemia speciosa L. are three ornamental plants that produce colorful flowers. The present study aimed to evaluate the phytochemicals and bioactivities of methanolic extracts of flowers from Delonix regia (DrFME), Cassia fistula (CfFME), and Lagerstroemia speciosa (LsFME). The presence of ten different chemical classes in varying degrees was confirmed while qualitatively screened. During quantitative determination, LsFME possesses the highest amount of total phenolic (418.0 mg/g), flavonoid (50.8 mg/g), and tannin (256.3 mg/g) contents. The extracts showed excellent antioxidant capacity in a concentration-dependent manner with the lowest IC50 value (41.51 μg/mL) displayed by LsFME. LsFME paralyzed the experimental worms at 2.95 min and killed at 3.96 min. DrFME was found to be more effective in thrombolytic (35.5% clot lysis) and anticoagulant activities. Negligible hemolytic activity (IC50 > 200 μg/mL) found for all extracts which suggest their less potential toxicity. The in vivo experiments revealed that the CfFME has the highest analgesic (64.34% pain inhibition) activity while LsFME has the highest antidiarrheal (70.27% inhibition) and antihyperglycemic (46.94% inhibition) activities at 400 mg/kg of body weight doses. This study has shown the presence of phytochemicals and potential bioactivities which indicates the possibility of these flowers to be used as a source of phytochemicals as well as safe and effective natural medicine.     

The cleavage of cyanogenic lipids by esterases

A method for the determination of esterases responsible for the cleavage of cyanogenic lipids is described. The cyanogenic esterase of Ungnadia speciosa seeds was examined. This enzyme was found exclusively in the lipid phase of homogenates, where also all cyanogenic lipids were located. The esterase exhibited maximum activity at pH 4.4.     

厦门地区紫薇二次成花调控技术研究

以控根器栽培的6年生紫薇(Lagerstroemia indica)为试材，在首次花后采用不同修剪强度、辅助追肥等综合调控措施进行处理，建立紫薇二次开花花期调控技术体系。结果表明，植株修剪和追肥均可促进紫薇二次开花。其中，紫薇首花后修剪4/5的抽生新枝，间隔两周根部追施一次150～180 g阿康复合肥，现蕾后间隔5 d叶面喷施一次花多多2号500倍液，两种肥料分别施用两次效果最佳。紫薇二次开花的盛花期、花枝长度及花序数量均显著高于其他处理；花期天数与其他处理相比处于较高水平，控花期间每两周喷施一次1000倍液啶虫脒和800倍液三唑酮，可有效防治紫薇长斑蚜、白粉病和煤烟病，保证紫薇正常花芽分化。