传统中药白芍原植物分类鉴定及根形态解剖研究

对我国主产地的白芍(Radix Paeonia alba)原植物10个居群进行调查及标本采集,植物鉴定结果为：川白芍原植物粉红花居群为原变种芍药Paeonia lactiflora Pall,白花居群为芍药变种毛果芍药P.lactiflora var.trichocarpa(Bunge)Stern;毫白芍原植物线条居群和蒲棒居群均为芍药;杭白芍原植物红花、白花、粉红花居群均为毛果芍药;陕西韩城、江苏东海、山东荷泽白芍均为芍药,各居群在花色及形态上有明显而稳定的变异。根横切面解剖结构显示,按木质部的排列方式可将白芍原植物10个居群分为两大类：第一类为有呈两个不相连的扇形中央导管群,并且有狭长、具分枝的从形成层到根中央部分连续排列的木质部,基本上是原植物芍药的植物特征,其中毫白芍线条居群兼有毛果芍药和芍药的特征;第二类为具有不明显的根中央扇形导管束,导管束呈环状围绕中央排列,并且有粗短不分枝的靠近形成层处成群的导管,与原植物毛果芍药的特征基本一致,其中杭白芍红花居群与川白芍白花居群根中央导管群呈现较明显的2个分离扇形排列,类似芍药。白芍原植物的种分类定位与花色无密切关联,但由于性状的稳定,可以考虑作为变种或变型定位。     

Flavonoid glycosides from Centaurea pseudoscabiosa subsp. pseudoscabiosa from Turkey

Three flavonoid glycosides were isolated and characterized, together with a further 13 substances belonging to various classes of compounds, in particular two phenolic acids, a coumarin, a sugar and nine flavonoids from the flowered aerial parts of Centaurea pseudoscabiosa subsp. pseudoscabiosa Boiss. et Buhse (Asteraceae). Some considerations about their evolutionary meaning are provided.     

Floral and vegetative morphometrics of five Pleurothallis (Orchidaceae) species: correlation with taxonomy,phylogeny, genetic variability and pollination systems

Morphometric analyses of vegetative and floral characters were conducted in 21 populations of five Pleurothallis (Orchidaceae) species occurring in Brazilian 'campo rupestre' vegetation. A phylogenetic analysis of this species group was also carried out using nuclear ribosomal DNA internal transcribed spacers (ITS1 and ITS2). Results of the ordination and cluster analyses agree with species' delimitation revealed by taxonomic and allozyme studies. The groups formed in ordination analysis correspond to the pollinator groups determined in a previous pollination study. Relationships among the species in the cluster analysis using only vegetative characters are similar to those found in a previous allozyme study, but those indicated by cluster analysis using only floral characters differ. These results support the hypothesis that floral similarities are due to convergence driven by similar pollination mechanisms, and therefore floral traits may not be good indicators of phylogenetic relationships in this group. The results of the phylogenetic analysis support this conclusion to some extent. There is no correlation between genetic (allozyme) and morphological variability in the populations nor in the way this variability is distributed among conspecific populations. We describe a new subspecies of Pleurothallis ochreata based on differences in vegetative and chemical characters as well as geographic distribution. Absence of differentiation in floral characters, attraction of the same pollinator species, interfertility and genetic similarity support the argument for subspecific rather than specific status.     

Effect of Azospirillum-mediated plant growth promotion on the development of bacterial diseases on fresh-market and cherry tomato

AIMS: Plant growth-promoting (PGP) activity of two Azospirillum strains and their effects on foliar and vascular bacterial diseases were evaluated on fresh market and cherry tomato. METHODS AND RESULTS: Tomato seeds were inoculated with A. brasilense Sp7 or Azospirillum sp. BNM-65. Four-week-old plants were challenge-inoculated with Clavibacter michiganensis subsp. michiganensis (bacterial canker) or with Xanthomonas campestris pv. vesicatoria (bacterial spot). Azospirillum-induced PGP was greater on cherry than on fresh-market tomato. Cherry tomato was more resistant to bacterial canker but more susceptible to bacterial spot than the fresh-market tomato. Canker severity was not affected by Azospirillum seed treatments. However, leaf- and plant-death were delayed on Azospirillum-treated plants compared with nontreated controls. Azospirillum increased the bacterial spot severity on cherry but not on fresh-market tomato. CONCLUSIONS: PGP was observed on both tomato genotypes, although growth effects were larger on cherry tomato. Also, Azospirillum treatments may alter tomato susceptibility to bacterial diseases. SIGNIFICANCE AND IMPACT OF THE STUDY: The interaction between PGP rhizobacteria like Azospirillum spp., not known to induce systemic resistance, with plant pathogens distantly located is frequently overlooked. This work demonstrates the importance of this kind of evaluation.     

Identification and purification of the 69-kDa intracellular protease involved in the proteolytic processing of the crystal delta-endotoxin of Bacillus thuringiensis subsp. tenebrionis

The dynamics of appearance of intracellular proteases in relation to the synthesis of crystal delta-endotoxin was studied to identify the native intracellular protease(s) involved in the proteolytic processing of the 73-kDa protoxin of Bacillus thuringiensis subsp. tenebrionis. In vitro proteolytic activation of the 73-kDa protoxin indicated the possible role of 69-kDa protease in the proteolytic processing of 73-kDa protoxin. The purified 69-kDa protease was able to cause the proteolytic activation of the 73-kDa protoxin to 68-kDa toxin and this conversion was inhibited by ethylenediamine tetraacetic acid and 1,10-phenanthroline.     

紫斑牡丹及其一新亚种

本文回顾了有关紫斑牡丹的调查和分类历史。它曾被混同于 P．suffruticosa,P．papaveracea 及P．suffruticosa var．papaveracea。它以叶2至3回羽状复叶,小叶17～33,花瓣白色,基部有大紫斑, 花丝黄色,花盘和柱头淡黄色区别于近缘种。种下分化为两个异域的亚种;秦岭北坡的紫斑牡丹小叶全 部或大部分分裂,是一个新亚种,P．rockii subsp．taibaishanica,而P.rockii subsp．linyanshanii T.Hong et G．L.ostii则是P．rockii subsp．rockii的多余名。     

大花黄牡丹分类学地位的研究

通过野外调查、引种试验,对大花黄牡丹与黄牡丹的形态特征、生长和繁殖特性进行了综合比较研究,结果表明,二者之间在植株高度、心皮数目、花色、花瓣基部有无棕红斑及繁殖特性等存在明显差异;同时,染色体组型、带型及蛋白亚基构成分析也表明二者之间有明显差异,因此我们认为,大花黄牡丹应上升为种的等级：Ｐａｅｏｎｉａ ｌｕｄｌｏｗｉｉ（Ｓｔｅｒｎ ｅｔ Ｔａｙｌｏｒ）Ｊ．Ｊ．Ｌｉ ｅｔ Ｄ．Ｚ．Ｃｈｅｎ,ｓｔａｔ     

An Investigation on Strains of Clavibacter michiganensis subsp. michiganensis in North and North West of Iran

Tomato bacterial canker disease was first reported from Urmiyeh in West Azerbaijan province in Iran. The disease causes lesion (canker), wilting and dryness of infected plants, leaf and fruit spots and the decline of the whole plant. Out of 102 isolates obtained from the fields in the major tomato producing areas of understudy regions, 98 were found Gram positive, yellow‐pigmented isolates, identified as Clavibacter michiganensis subsp. michiganensis based on the morphological and biochemical characteristics described in previous studies. Among these strains, 64 were virulent and 34 showed poor virulence. A strain of Cmm (NCPPB382) was used as a check (standard) in all steps of this study. DNA fingerprinting with repetitive‐sequence‐based PCR (rep‐PCR) (BOX primer) carried out among 11 representative strains (eight strains from West Azerbaijan, two from Golestan and one as standard). The most virulent strain was chosen as representative in each location. Dendrograms were prepared using NTSYS‐pc version 2/o2e software, unweighted pair group with arithmetic average method and simple matching similarity coefficient. According to the site of cut‐off line, three groups (clusters) with 82/5% similarity and six groups with 55% similarity were separated based on biochemical and SDS‐PAGE data, and rep‐PCR reactions respectively. Low similarity among groups (55%) can be explained as high genetic diversity among the strains. One strain of west Azerbaijan and the strains of Golestan, clustered in the same group suggesting that they may have been originated from a common source. Other strains of west Azerbaijan were clustered into different groups including II, III, IV, V and VI, suggesting the possibility of occurrence of different populations in a geographical region.     

No loss of genetic diversity in small and isolated populations of Medicago sativa subsp. falcata

Molecular allozyme markers of three polymorphic isozymes were used to estimate the genetic diversity among the seed progeny in fragmented Estonian populations of sickle medic Medicago sativa ssp. falcata L. depending on the population size and the isolation degree. Genetic diversity H_e was high in all populations, ranging between 0.795 and 0.893. No correlation between the genetic diversity measures and population size or isolation distance was found. Even the smallest population had equally high genetic diversity as about a hundred times larger population. Genetic differentiation of populations into two major groups was associated with the geographic position of populations, except one remote population. Elimination of seed progeny of reduced fitness by embryo abortion and continuous yearlong contribution of the highly heterozygous progeny through the soil seed bank are considered as important supplementary factors that have contributed to maintaining high levels of genetic diversity in populations of sickle medic in addition to its autotetraploid nature and perennial life form.     

Pectolytic Bacteria Associated with Soft Rot of Calla Lily (Zantedeschia spp.) Tubers

Soft rot is the most important disease on calla lily in Poland. The isolation of the presumptive pathogen from symptomatic tubers on nutrient agar yielded bacteria with different colony morphology. Of 41 isolates collected, 10 showed pectolytic activity on crystal violet pectate medium and caused soft rot on potato slices. All pectolytic bacteria appeared to be Gram‐negative rods producing typical soft rot on inoculated leaf petioles of calla lily. Bacteria with colonies which morphologically resembled those used for inoculation were re‐isolated from diseased petioles. Their identification was based on phenotypic characters and sequence of the gene fragment coding 16S rRNA. It was found that, in addition to Pectobacterium carotovorum subsp. carotovorum, soft rot of calla lily can be caused by Pectobacterium carotovorum subsp. atrosepticum, Pseudomonas marginalis, Pseudomonas veronii and Chryseobacterium indologenes. The latter two are described for the first time as plant pathogens. The pectolytic activity of all identified bacteria, except that of P. carotovorum subsp. atrosepticum, was lower than that of P. carotovorum subsp. carotovorum, but strains of P. veronii showed a higher activity than P. marginalisand C. indologenes species.