Ipangulines and minalobines, chemotaxonomic markers of the infrageneric Ipomoea taxon subgenus Quamoclit, section Mina

A comprehensive GC-MS analysis of 8 Ipomoea species belonging to the subgenus Quamoclit, section Mina revealed that the members of this taxon form combinations of two necine bases with rare necic acids resulting in unique pyrrolizidine alkaloids. The occurrence and diversity of these metabolites show remarkable variations: Some species, especially Ipomoea hederifolia and Ipomoea lobata, are able to synthesize a large number of alkaloids whereas others, especially Ipomoea coccinea and Ipomoea quamoclit, are poor synthesizers with only a few compounds. However, these metabolites are apparently chemotaxonomic markers of this infrageneric taxon in general. They represent either esters of (-)-platynecine (altogether 48 ipangulines and 4 further esters including results of a previous study) or esters of (-)-trachelanthamidine, an additional novel structural type called minalobines (altogether 21 alkaloids). Both types are characterized by section-specific rare necic acids, e.g., ipangulinic/isoipangulinic acid, phenylacetic acid. The alkaloids of Ipomoea cholulensis, I. coccinea, I. hederifolia, Ipomoea neei, and Ipomoea quamoclit were mono and diesters of platynecine. Minalobines turned out to be metabolites of I. lobata (Cerv.) Thell. (syn.: Mina lobata Cerv.) lacking ipangulines. The major alkaloid of this species, minalobine R, has been isolated and identified as 9-O-(threo-2-hydroxy-2-methyl-3-phenylacetoxy-butyryl)-(-)-trachelanthamidine on the basis of spectral data. Apparently only two of the species included in this study, Ipomoea cristulata and Ipomoea sloteri, are able to synthesize both, ipangulines as well as minalobines. Minalobine O could be isolated as a major alkaloid of I. cristulata, its structure has been established as 9-O-(erythro-2-hydroxy-2-methyl-3-tigloyloxy-butyryl)-(-)-trachelanthamidine on the basis of spectral data.     

水蕹菜（Ipomoea aquatica）对含银废水的净化功能研究

 本文通过对水蕹菜净化含银废水的室内外静、动态试验研究得出：(1)水蕹菜对离子态银(Ag+)的去除速率高于对络合态银(Ag(S2O3)2)3-的去除速率即KAg+>K[Ag(S2O3)2]3-;(2)水蕹菜对银的净化率R与污水停留时间t呈指数函数关系(R=AeB/t,A、B为常数,B<0),其表面去除负荷Ps则与t呈幂函数关系(Ps=AtB B<0);(3)试验证明水蕹菜是生物净化含银废水的优良品种之一。     

Complex anthocyanins from Ipomoea congesta

Six acylated anthocyanins have been isolated from the flowers of Ipomoea congesta R. Brown. One has been previously described as an acylated peonidin derivative. Three others are isomers, derived from peonidin-3-(caffeylsophoroside)-5-glucoside. The fifth was characterised as peonidin-3-(p-coumarylcaffeylsophoroside)-5-glucoside and the last as peonidin-3-(coumarylsophoroside)-5-glucoside. It is noteworthy that the anthocyanins found in this species have the same glycosidic pattern, 3-sophoroside-5-glucoside, as those reported for the cyanidin derivatives in Ipomoea cairica flowers. Acylated anthocyanin occurrence in Tubiflorae order is of chemotaxonomical value.     

五爪金龙茎的解剖结构

运用常规石蜡切片、显微观察及显微照相的方法, 对五爪金龙( Ipomoea cairica) 茎的结构进行了观察研究, 结果表明: 五爪金龙茎的解剖结构以初生结构为主, 维管形成层已经形成, 但次生结构尚不发达。通常具3～6 个空腔, 初步推断其为裂生式分泌道; 表皮外弦向壁增厚, 具角质层, 具气孔及气室;紧贴表皮内方的1～3 层和皮层最内1～3 层的细胞可能为分泌细胞; 具双韧维管束, 木质部极为发达, 导管细胞紧密排列, 围绕内韧皮部和中央的髓而成一圆周; 形成层位于外韧皮部与木质部之间; 茎中央是大型薄壁细胞构成的髓, 具簇晶。     

五爪金龙茎的解剖结构

运用常规石蜡切片、显微观察及显微照相的方法,对五爪金龙(Ipomoea cairica)茎的结构进行了观察研究,结果表明:五爪金龙茎的解剖结构以初生结构为主,维管形成层已经形成,但次生结构尚不发达。通常具3~6个空腔,初步推断其为裂生式分泌道;表皮外弦向壁增厚,具角质层,具气孔及气室;紧贴表皮内方的1~3层和皮层最内1~3层的细胞可能为分泌细胞;具双韧维管束,木质部极为发达,导管细胞紧密排列,围绕内韧皮部和中央的髓而成一圆周;形成层位于外韧皮部与木质部之间;茎中央是大型薄壁细胞构成的髓,具簇晶。     

Structure proof of muricatin B: 11-hydroxy hexadecanoic acid dirhamnoside

Synthesis of (+)-11-hydroxyhexadecanoic acid-O-(4-O-α-L-rhamnopyranosyl)-α-L- rhamnopyranoside showed that muricatin B from Ipomoea muricata does not contain the proposed β- but an α-linked dirhamnoside moiety. This is the first reported synthesis of a naturally occurring O-glycoside of a long chain hydroxy-fatty acid.     

甘薯与牵牛EST资源的SSR信息分析

为挖掘番薯（Ipomoea）属EST-SSR资源,从NCBI数据库下载23406条甘薯（Ipomoea batatas (L.) Lam.）EST和62282条牵牛（Ipomoea nil (L.) Roth）EST,利用生物信息学软件预处理、去冗余、拼接处理后得到12812条无冗余的甘薯EST（6.70 Mb）和28422条牵牛唯一序列（17.19 Mb）。对这些序列进行SSR搜索,在甘薯上获得328个SSR位点,发生频率为2.56%;牵牛上筛选到962个SSR位点,出现频率为3.38%。甘薯和牵牛EST-SSR具有多个共同特征：在SSR位点中,主要是二核苷酸重复类型,其次是三核苷酸重复;在二核苷酸重复中,出现最多的重复基序为AG/CT,其次是AT/AT;在三核苷酸重复中,主要基序是AAG/CCT;SSR位点的长度主要集中在20~22 bp。结果表明,这些搜索出的EST-SSR重复基序类型丰富、多态性潜能高,具有较高的开发和利用价值。     

Hydrolytic fragmentation of seed gums under microwave irradiation

The seed gum solutions of Ipomoea purga, Ipomoea palmata, Ipomoea dasysperma, Cyanaposis tetragonolobus (Guar gum) and Crotolaria medicaginea were microwave (MW) irradiated and their degradation to oligo and monosaccharides was investigated. The gum solutions were fragmented into oligosaccharides/constituent monosaccharides depending upon the length of MW exposure in presence of catalytic amount of mineral acid or even when no acid was used. A mechanism for the microwave induced hydrolytic degradation of the seed gums has been proposed. The MW exposure time required for the partial and complete degradation of the gums was found dependent on the types of the linkages and degree of the branching present in the gums.     

Effect of Light and NaCI Salinity on the Growth of Callus Cultures of Ipomoea pes-caprae (L.) R. Brown and Ipomoea batatas (L.) Lam

Callus cultures of Ipomoea pes-caprae and I. batatas were establishedon MS medium containing 10^–5 M 2,4-D and 10^–8 Mbenzyladenine. Ipomoea pes-caprae calli exhibited green pigmentationand grew better in the light than in darkness. Callus tissuesof I. batatas showed a pale-yellow colouration and they grewat the same rate in light as in dark conditions. I. pes-capraeand I. batatas callus cultures were sensitive to the presenceof 60 mM NaCl in the culture medium, the growth of the formerbeing more sensitive in light than in darkness. The significanceof the responses of I. pes-caprae callus cultures in relationto the mechanism of salt tolerance is discussed. Ipomoea batatas, Ipomoea pes-caprae, sweet potato, railroad vine, callus cultures, salinity, light     

城市污泥和化肥对水稻土种植的通菜中邻苯二甲酸酯（PAEs）的影响

对水稻土施用城市污泥和化肥盆栽通菜,应用GC／MS联机检测技术对通菜中6种邻苯二甲酸酯化合物(PAEs)进行分析,探讨施肥对通菜中PAEs含量的影响,结果表明,各处理通菜中6种PAEs化合物的总含量(∑PAEs)在2．129～7.111mg·kg^-1之间,依次为广州污泥+化肥(7．111mg·kg^-1)>广州污泥(4．767mg·kg^-1)>佛山污泥(3;569mg·kg^-1)>佛山污泥+化肥(3．305mg·kg^-1)>化肥(2．638mg·kg^-1)>空白对照(2．129mg·kg^-1)。显示了施肥造成通菜中∑PAEs不同程度的提高,各处理通菜中的PAEs均以个别化合物为主,其中空白对照、化肥、佛山污泥和广州污泥处理的通菜中邻苯二甲酸丁基苄基酯(BBP)占∑PAEs的40％～81％。佛山污泥+化肥处理的通菜中邻苯二甲酸正二丁酯(DnBP)占∑PAEs的56％,而广州污泥+化肥处理的通菜中邻苯二甲酸丁基苄基酯(BBP)、邻苯二甲酸正二辛酯(DnOP)和邻苯二甲酸(2-乙基己基)酯(DEHP)各占∑PAEs的30％左右,通菜中∑PAEs和多数化合物的含量不同程度地大于其在根系中的含量。     

三种除草剂对五爪金龙的防除作用及2,4-D丁酯对环境的影响

用3种除草剂(2,4-D丁酯、麦草畏和塔隆)对五爪金龙(Ipomoea cairica L.Sweet)进行化学防除试验。结果表明:1.00 mL L-1的2,4-D丁酯可以彻底杀灭五爪金龙。喷施1.00 mL L-12,4-D丁酯20 d后,五爪金龙茎叶枯死率接近100%;60 d后五爪金龙的总生物量显著低于其它处理及对照;90 d后未出现生长恢复,最终盖度防效为99.8%。而喷施1.00 mL L-1的麦草畏40 d后,五爪金龙的茎叶枯死率为99.0%,但仍有少量存活的根,90 d后再次萌生率为10.0%;喷施1.00 mL L-1塔隆40 d后,五爪金龙的茎叶枯死率为100%,90 d后再次萌生率为100%。土壤残留分析表明:在有机质含量较高[(10.14±1.01)g kg-1]的土壤中2,4-D丁酯降解速率较快,半衰期为14 d,施药后80 d的土壤中已检测不到2,4-D丁酯。此外,在野外喷洒1.0 mL L-1的2,4-D丁酯对其它植物是安全的,施药1年后,样地内的植物均能恢复生长。因此,实践中可用1.00 mL L-1的2,4-D丁酯来防除五爪金龙。     

邻苯二甲酸酯在不同品种通菜-土壤系统中的累积效应研究

在邻苯二甲酸(2-乙基己基)酯(DEHP)不同污染程度的水稻土上盆栽不同品种通菜,应用GC／MS联机检测技术研究了通菜-土壤系统中DEHP的环境行为与归宿．结果表明,通菜中DEHP的含量为0．335～12．710mg·kg^-1,与土壤的污染程度呈正相关．不同品种通菜之间对DEHP的吸收累积效应存在显著差异,与其叶子大小存在一定的正相关关系．种植不同品种通菜后土壤中DEHP的残留量(1．424～19．834mg·kg^-1)存在显著差异．通菜对土壤中DEHP的BCFs都小于1．0,与土壤的污染程度呈负相关．不同通菜品种的BCFs之间存在显著差异,中等叶子通菜品种的BCFs相对较大。     

Transcriptome Sequencing of a Novel Albino Mutant of Hexaploid Sweetpotato

Plant Molecular Biology Reporter - Sweetpotato (Ipomoea batatas L), the herbaceous plant cultivated for its starchy storage roots, has a complex genome (2n?=?6x?=?90) with...     

Oviposition preference and larval performance of the sweet potato butterfly Acraea acerata on Ipomoea species in Ethiopia

• 1 The sweet potato butterfly Acraea acerata is an indigenous species in Ethiopia that has become a major pest on the introduced sweet potato Ipomoea batatas. To assess the role of wild Ethiopian Ipomoea species as host plants, the presence of larvae on wild ipomoeas was studied, and female oviposition choice and larval performance were tested on five wild ipomoeas, as well as on sweet potato.
• 2 In laboratory tests, oviposition and larval development were successful on two wild ipomoeas (Ipomoea tenuirostris and Ipomoea cairica) but no oviposition occurred on the remaining three species. Of the latter, larvae did not feed on Ipomoea hochstetteri and Ipomoea indica, and survival rates were extremely low on Ipomoea purpurea.
• 3 Sweet potato was a better host plant than I. tenuirostris and I. cairica in terms of oviposition preference, larval survival and pupal size; pupae were larger, resulting in more fecund female butterflies.
• 4 In the wild butterfly populations were abundant on I. tenuirostris but absent on I. cairica. Females also tended to prefer I. tenuirostris to I. cairica in oviposition choice experiments. However, no significant differences in performance were found between larvae raised on I. tenuirostris and I. cairica in the laboratory.
• 5 Wild populations of A. acerata also existed on Ipomoea obscura, a plant not investigated in the present study.
• 6 The abundance of A. acerata on wild ipomoeas is too low to likely affect butterfly population densities on sweet potato. However, wild populations may act as reservoirs subsequent to butterfly population bottlenecks on sweet potato.

     

An examination of the monophyly of morning glory taxa using Bayesian phylogenetic inference

The objective of this study was to obtain a quantitative assessment of the monophyly of morning glory taxa, specifically the genus Ipomoea and the tribe Argyreieae. Previous systematic studies of morning glories intimated the paraphyly of Ipomoea by suggesting that the genera within the tribe Argyreieae are derived from within Ipomoea; however, no quantitative estimates of statistical support were developed to address these questions. We applied a Bayesian analysis to provide quantitative estimates of monophyly in an investigation of morning glory relationships using DNA sequence data. We also explored various approaches for examining convergence of the Markov chain Monte Carlo (MCMC) simulation of the Bayesian analysis by running 18 separate analyses varying in length. We found convergence of the important components of the phylogenetic model (the tree with the maximum posterior probability, branch lengths, the parameter values from the DNA substitution model, and the posterior probabilities for clade support) for these data after one million generations of the MCMC simulations. In the process, we identified a run where the parameter values obtained were often outside the range of values obtained from the other runs, suggesting an aberrant result. In addition, we compared the Bayesian method of phylogenetic analysis to maximum likelihood and maximum parsimony. The results from the Bayesian analysis and the maximum likelihood analysis were similar for topology, branch lengths, and parameters of the DNA substitution model. Topologies also were similar in the comparison between the Bayesian analysis and maximum parsimony, although the posterior probabilities and the bootstrap proportions exhibited some striking differences. In a Bayesian analysis of three data sets (ITS sequences, waxy sequences, and ITS + waxy sequences) no supoort for the monophyly of the genus Ipomoea, or for the tribe Argyreieae, was observed, with the estimate of the probability of the monophyly of these taxa being less than 3.4 x 10(-7).     

Assessing the roles of roots and shoots in the accumulation of cadmium in two sweet potato cultivars using split-root and reciprocal grafting systems

Plant and Soil - The root cadmium (Cd) concentrations of sweet potato (Ipomoea batatas [L.] Lam.) cultivars vary greatly. In this study, we explored the role of shoots and roots in Cd accumulation...     

Isolation and culture of protoplasts from high anthocyanin-producing callus of sweet potato

Optimum conditions for the isolation and culture of protoplasts from high anthocyanin-producing callus of sweet potato (Ipomoea batatas) were investigated. Growth phase of callus and the ratio of callus-enzyme solution affected the yield of protoplasts. Composition of the medium and protoplast density were examined for protoplast culture.Small colonies were regenerated from the protoplasts. Upon transfer to light a high amount of anthocyanin was accumulated in these colonies.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - MES 2-(N-morpholino)-ethanesulfonic acid     

Notes on Convolvulus, Astripomoea, Ipomoea and Merremia (Convolvulaceae) from the Horn of Africa

The six new species Convolvulus scopulatus, a shrub from gypseous semidesert coastal plains in northern Somalia, Astripomoea procera, a woody climber in Acacia-Commiphora bushland on sand in south-central Somalia, Ipomoea hiranensis, a prostrate or climbing shrublet in Acacia-Commiphora bushland in rocky places on sandstone in south-central Somalia, Ipomoea galhareriana, a woody climber in bushland on sand in central Somalia, Ipomoea pogonantha, a woody climber in bushland usually on red soil over limestone in eastern and southern Ethiopia, southern Somalia and northern Kenya, and Ipomoea corrugata, a herb with trailing stems in bushland on sandy soil in south-central Somalia, are described, and illustrations are provided for most of them. The new combinations Ipomoea ovatolanceolata (= I. adenoides var. ovatolanceolata) and Merremia obtusa (= M. ampelophylla subsp. obtusa) are made, and a new synonymy is provided for M. ampelophylla. Merremia ellenbeckii is neotypified and M. lobata is placed in synonymy.     

A new species of Ipomoea section Quamoclit (Convolvulaceae) from the Caribbean and a new combination for a Mexican species

Ipomoea praematura sp. nov. differs fromI. hederifolia L., its closest congener, in flower color and phenology, capsule shape, and seed shape and pubescence. Other distinguishing characteristics show some overlap with its more widespread and variable relative. The new species grows along the Caribbean coast of South America and on nearby islands. The recently described MexicanQuamoclit fissifolia McPherson is transferred asIpomoea fissifolia.