Comparative effects of Glomus mosseae and P fertilizer on foliar mineral composition of Acacia senegal seedlings inoculated with Rhizobium

Summary A factorial experiment with two controlled factors was conducted in the greenhouse with Acacia Senegal seedlings. The substrate was a degraded sandy soil (Dior soil) poor in available P (11 ppm — Olsen). The first controlled factor was soil sterilization, with two levels: (A) sterilized soil; (B) non-sterilized soil. The second factor was fertilization, with six levels: (1) uninoculated control; (2) inoculation with Rhizobium (ORS 1007); (3) inoculation with Glomus mosseae; (4) double inoculation with ORS 1007 and G. mosseae; (5) inoculation with ORS 1007 and 30 ppm phosphorus per plant; (6) inoculation with ORS 1007 and 60 ppm phosphours. The combination of the two factors and their levels led to 12 different plant treatments (A1–A6 and B1–B6). Compared to the control B1, the B5 and B6 treatments containing phosphorus increased: nodule dry weight about 7 times ; leaf dry weight about 4 times ; total N, P and Mg 4–5 times; total K and Ca 3–4 times. The mycorrhizal inoculation had the same positive effect on plant growth and mineral composition but with lower values. Plants inoculated with Rhizobium alone gave the lowest results. The A1 treatment gave lower values than B1. Foliar mineral contents varied within a narrow range (20–30%).     

“HAIRY CANOLA” – Arabidopsis GL3 Induces a Dense Covering of Trichomes on Brassica napus Seedlings

Transformation with the Arabidopsis bHLH gene 35S:GLABRA3 (GL3) produced novel B. napus plants with an extremely dense coverage of trichomes on seedling tissues (stems and young leaves). In contrast, trichomes were strongly induced in seedling stems and moderately induced in leaves of a hairy, purple phenotype transformed with a 2.2 kb allele of the maize anthocyanin regulator LEAF COLOUR (Lc), but only weakly induced by BOOSTER (B-Peru), the maize Lc 2.4 kb allele, or the Arabidopsis trichome MYB gene GLABRA1 (GL1). B. napus plants containing only the GL3 transgene had a greater proportion of trichomes on the adaxial leaf surface, whereas all other plant types had a greater proportion on the abaxial surface. Progeny of crosses between GL3⁺ and GL1⁺ plants resulted in trichome densities intermediate between a single-insertion GL3⁺ plant and a double-insertion GL3⁺ plant. None of the transformations stimulated trichomes on Brassica cotyledons or on non-seedling tissues. A small portion of bHLH gene-induced trichomes had a swollen terminal structure. The results suggest that trichome development in B. napus may be regulated differently from Arabidopsis. They also imply that insertion of GL3 into Brassica species under a tissue-specific promoter has strong potential for developing insect-resistant crop plants. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

内生真菌与苍术粉对连作花生根际微生物区系和微量元素的影响

通过盆栽试验,研究了内生真菌拟茎点霉B3(Phomopsis liquidambari)及苍术(Atractylodes lancea)粉联合施用对连作花生根际土壤微生物区系、酶活性及有效态微量元素(Mo、B、DTPA-Fe、Zn、Cu、Mn)含量的影响。结果表明:内生真菌B3和苍术粉复合处理比内生真菌B3处理的荚果和秸秆产量分别增加10.28%和14.11%,内生真菌B3处理与正常施肥相比显著提高了根瘤数量、荚果和秸秆产重,各处理组与正常施肥对照相比分枝数和根长无显著差异。B3处理与对照相比显著提高了种子期、结荚期和成熟期根际土壤可培养细菌和放线菌数量,B3和苍术粉复合处理与对照相比显著提高种子期、花期和成熟期可培养真菌和放线菌数量;细菌DGGE指纹图谱聚类分析表明,B3和苍术粉复合处理相对于正常施肥处理,显著改变种子期、苗期、花期和成熟期花生根际土壤细菌群落结构,同时苗期、花期和结荚期的细菌条带数和香农指数也有所提高,真菌DGGE指纹图谱聚类分析表明,B3和苍术粉复合处理对真菌群落影响较大,除种子期以外的生育期真菌条带数和香农指数都有明显提高,花期真菌群落结构变化最大,相似度仅为49.6%。花生关键生育期(花期和结荚期)根际土壤脲酶和蔗糖酶活性B3处理和复合处理都显著高于正常施肥对照,促进了连作花生生态系统的物质循环和能量流动。B3和苍术粉复合处理促进了花生生长发育必需微量元素Mo、B、Fe、Zn、Mn的活化,花生叶片和籽粒中微量元素Mo、B、Fe的积累显著增加。研究结果表明,内生真菌和苍术粉联合施用能有效改善连作花生根际微生物区系,提高土壤酶活性,促进微量元素的活化和吸收,对缓解花生连作障碍具有重要意义。     

Development of a pair of bifunctional expression vectors for <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Bacillus licheniformis</Emphasis>

A pair of bifunctional expression vectors, pBL-WZX and pHY-WZX, for Escherichia coli and Bacillus licheniformis was constructed to express interesting genes in a secretory manner. The vectors contain an expression cassette consisted of the promoter and signal peptide region of B. licheniformis amyL as well as an artificial multiple cloning site and a terminator and utilize kanamycin-resistance and/or tetracycline-resistance for selection in both B. licheniformis and E. coli. Both vectors contain a part of 3′ terminal fragment of B. licheniformis amyL. The 5′-terminal or 3′-terminal fragment of B. licheniformis amyL can cause the integration and amplification of expression cassette in the chromosome of B. licheniformis under a kanamycin-selection pressure. pBL-WZX is an integrational vector while pHY-WZX is free one for B. licheniformis. Both vectors were succeeded in secretory expression of manL in both B. licheniformis and E. coli.     

Heterotopic expression of class B floral homeotic genes supports a modified ABC model for tulip (Tulipa gesneriana)

In higher eudicotyledonous angiosperms the floral organs are typically arranged in four different whorls, containing sepals, petals, stamens and carpels. According to the ABC model, the identity of these organs is specified by floral homeotic genes of class A, A+B, B+C and C, respectively. In contrast to the sepal and petal whorls of eudicots, the perianths of many plants from the Liliaceae family have two outer whorls of almost identical petaloid organs, called tepals. To explain the Liliaceae flower morphology, van Tunen et al. (1993) proposed a modified ABC model, exemplified with tulip. According to this model, class B genes are not only expressed in whorls 2 and 3, but also in whorl 1. Thus the organs of both whorls 1 and 2 express class A plus class B genes and, therefore, get the same petaloid identity. To test this modified ABC model we have cloned and characterized putative class B genes from tulip. Two DEF- and one GLO-like gene were identified, named TGDEFA, TGDEFB and TGGLO. Northern hybridization analysis showed that all of these genes are expressed in whorls 1, 2 and 3 (outer and inner tepals and stamens), thus corroborating the modified ABC model. In addition, these experiments demonstrated that TGGLO is also weakly expressed in carpels, leaves, stems and bracts. Gel retardation assays revealed that TGGLO alone binds to DNA as a homodimer. In contrast, TGDEFA and TGDEFB cannot homodimerize, but make heterodimers with PI. Homodimerization of GLO-like protein has also been reported for lily, suggesting that this phenomenon is conserved within Liliaceae plants or even monocot species.these authors contributed equally to this work     

Rhodotorula himalayensis sp. nov., a novel psychrophilic yeast isolated from Roopkund Lake of the Himalayan mountain ranges, India

Twenty-five psychrophilic yeasts were isolated from the soil of Roopkund Lake, Himalayas, India. Two colony morphotypes were identified and representatives of ‘morphotype 1’ were identified as Cryptococcus gastricus. Representatives of ‘morphotype 2’, namely 3A^T, 4A, 4B and Rup4B, showed similar phenotypic properties and are identical with respect to the nucleotide sequence of the ITS1-5.8S rRNA gene-ITS2 region and D1/D2 domain of the 26S rRNA gene. The sequence of D1/D2 domain of 3A^T shows 97.6–98.8% similarity with Rhodotorula psychrophila CBS10440^T, Rhodotorula glacialis CBS10437^T and Rhodotorula psychrophenolica CBS10438^T and in the neighbour-joining phylogenetic tree strains; 3A^T, 4A, 4B and Rup4B form a cluster with Rhodotorula glacialis and Rhodotorula psychrophila. Strains 3A^T, 4A, 4B and Rup4B also differ from their nearest phylogenetic relatives in several biochemical characteristics such as in assimilation of d-galactose, l-sorbose, maltose, citrate, d-glucuronate and creatinine. Thus, based on the phylogenetic analysis and the phenotypic differences 3A^T, 4A, 4B and Rup 4B are assigned the status of a new species of Rhodotorula for which the name Rhodotorula himalayensis sp. nov. is proposed with 3A^T as the type strain (=CBS10539^T =MTCC8336^T). GenBank/EMBL accession numbers for (partial) 18SrRNA gene-ITS1-5.8S rRNA gene-ITS2-26S rRNA gene (partial) sequences of Rhodotorula himalayensis sp. nov. 3A^T is AM410635.     

A chromosome-specific sequence common to the B genome of polyploid wheat and Aegilops searsii

A low-copy, non-coding chromosome-specific DNA sequence, isolated from common wheat, was physically mapped to the distal 19% region of the long arm of chromosome 3B (3BL) of common wheat. This sequence, designated WPG118, was then characterized by Southern hybridization, PCR amplification and sequence comparison using a large collection of polyploid wheats and diploid Triticum and Aegilops species. The data show that the sequence exists in all polyploid wheats containing the B genome and absent from those containing the G genome. At the diploid level, it exists only in Ae. searsii, a diploid species of section Sitopsis, and not in other diploids including Ae. speltoides, the closest extant relative to the donor of the B genome of polyploid wheat. This finding may support the hypothesis that the B-genome of polyploid wheat is of a polyphyletic origin, i.e. it is a recombined genome derived from two or more diploid Aegilops species.     

细叶蒿草炭黑粉菌新种及中国黑粉菌补遗VII

本文报道炭黑粉菌一新种,即细叶蒿草炭黑粉菌(Anthracoidea filifoliae L. Guo sp.nov.)和4个我国新记录种:1)角孢炭黑粉菌(A. angulata(H. Sydow) Boidol & Poclt), 2)黍状苔炭黑粉菌(A. paniceae Kukkenen), 3)狼尾草团黑粉菌(Sorosporium penniseti Mundkur)和4)米勒粘孢黑粉菌(Tolyposporium muellerianum (Thuemen) McAlpine)。     

Review of rotifers and crustaceans in highly acidic environments of pH values ≤3

A review of the literature on rotifers and crustacean zooplankton in highly acidic environments revealed that data from eleven aquatic environments on three continents (America, Europe, Japan) with a pH 3 are available. Seven sites are influenced by volcanism or weathering processes in the catchment area, four others originated from human mining activities. Species richness was generally low. Only 16 species are found and 1–11 species are reported for each area. These studies clearly show that small littoral or benthic rotifers predominate over crustaceans under highly acidic conditions. In the Lusatian mining area (Germany), all lakes are colonized by zooplankton, even the most acidic one with a pH of 2.3. The core community consists of the rotifers Cephalodella hoodi, C. gibba, Elosa worallii and Rotaria rotatoria, with C. hoodi and E. worallii the most abundant. Larger species, such as the rotifer Brachionus sericus or the cladoceran Chydorus sphaericus, occur at a pH close to 3. A similar pattern is reported from acidic mining lakes in Illinois, U.S.A. Many of these species can also be found in less acidic softwater or even alkaline environments due to the tolerance of a broad range of pH values. Elosa worallii and Brachionus sericus are probably the most acidophilic rotifer species, though at least the latter can also grow at neutral pH in the laboratory. Clear understanding of the pH limits of B. sericus in nature may also have been complicated by the fact that it has probably in the past been wrongly named as B. urceolaris (phenotype `sericus'). The typical B. urceolaris cannot tolerate extremely low pH. Overall, generalist species with a worldwide distribution seem to play the major role in the colonization of anthropogenic highly acidic lakes.     

Implication of two glutathione S-transferases in the optimal metabolism of m-toluate by Sphingomonas yanoikuyae B1

A putative glutathione S-transferase (GST) gene (bphK) was identified in the meta-cleavage operon for the degradation of m-toluate by Sphingomonas yanoikuyae B1. Disruption of bphK resulted in the loss of GST activity against 1-chloro-2,4-dinitrobenzene and a much increased lag time of the mutant strain MB3 (bphK::Km) following subculture into m-toluate medium. In contrast, an increased lag time was not observed when MB3 was grown on biphenyl or m-xylene and MB3 showed normal growth on m-toluate when complemented with a subclone containing the bphK gene only. Furthermore, an additional GST activity was detected in MB3. The induction timing of this second GST activity coincided with the beginning of the exponential growth phase of MB3 on m-toluate, reached maximal activity within three hours, and then dropped sharply to the basal level. Thus, it is apparent that BphK and/or the second GST are necessary for optimal growth of B1 on m-toluate. This revised version was published online in June 2006 with corrections to the Cover Date.     

不同光质对红花檵木愈伤组织生长及黄酮类物质含量的影响

该试验以红花檵木叶片诱导的愈伤组织为试验材料,以黑暗(CK)为对照,分别进行白光(W)、红光(R)、蓝光(B)、蓝紫光(BP)、蓝光+UV-A(B+UV A)和UV-A处理15d和30 d,通过对愈伤组织的生长、生理指标、花色素苷和总黄酮含量的比较分析,探讨光质对红花檵木愈伤组织生长和黄酮类物质含量的影响.结果 显示:...     

青花菜BoSCL3基因的克隆和渍水胁迫下的表达特征分析

为了解SCL3 (scarecrow-like 3)基因的功能,从青花菜(Brassica olreacea var. italica)中克隆得到1个SCL3基因,命名为BoSCL3,其cDNA全长1 355 bp,编码446个氨基酸。BoSCL3分子量为49.96 kD,为疏水性蛋白,与油菜(B. napus)、芜菁(B. rapa)中SCL3蛋白的亲缘关系最近,同科植物的SCL3具有较高的同源性。荧光定量PCR分析结果表明,青花菜BoSCL3基因表达量随渍水胁迫时间延长先下降后上升,推测其可能参与渍水胁迫响应。这为探讨青花菜BoSCL3基因响应渍水胁迫的分子机制提供理论依据。     

Intergeneric (intersubtribe) hybridization between Moricandia arvensis and Brassica A and B genome species by ovary culture

Summary Intergeneric hybrids between Moricandia arvensis (C₃–C₄ intermediate species) and Brassica A and B genome species (B. campestris and B. nigra) were produced via ovary culture. When M. arvensis was used as a female parent, the hybrid embryo yield (0.25–0.45 embryo per pollination) was similar between two genomes, regardless of the male parent. The reciprocal hybrid using B. campestris as a female was also obtained, although yield of embryo was lower (0.02 embryo per pollination). On the other hand, no hybrids were obtained without the in vitro technique. As most hybrid embryos could not develop normal shoots, plants were regenerated by inducing shoots on the cultured hypocotyl. The hybrid nature of the regenerated plant was confirmed morphologically and cytogenetically. A certain amount of bivalents (2.52-2.71) in the hybrids indicated the existence of partial chromosome homology between two genera. The present results indicate that ovary culture is an effective technique for overcoming the crossing barrier between M. arvensis and Brassica cultivated species.     

Phylogenetic relationships among genera in theLiliaceae-Asparagoideae-Polygonatae s.l. inferred fromrbcL gene sequence data

The chloroplast gene encoding ribulose-1,5-bisphosphate-carboxylase (rbcL) was sequenced for phylogenetic analysis of 13 species (10 genera) in the tribePolygonatae s.l. of theLiliaceae-Asparagoideae. The data were analysed using maximum parsimony and neighbour-joining methods. There were 233 phylogenetically informative sites out of 1368 base pairs compared. The results suggest that there are three monophyletic groups withinPolygonatae s.l. with high bootstrap confidence values. Group A representsPolygonatae s.str., with generaMaianthemum, Smilacina, Convallaria, Disporopsis, andPolygonatum. Group B containsUvularia andDisporum and group C includesStreptopus, Tricyrtis, Clintonia, andProsartes. The study suggests thatPolygonatae s.l. are not a monophyletic group, including at least three groups of different phylogenetic origin. Monophyly of the taxa within groups A, B, and C is supported by the high bootstrap confidence values (85–100%) of the bootstrap replications for both parsimony and neighbour-joining methods. The differences between each group (calculated as 100x base substitutions per site) were 6.99–9.03 for group A and B, 4.92–7.35 for A and C, and 6.66–7.57 for B and C.     

Mapping of Fhb2 on chromosome 6BS: a gene controlling Fusarium head blight field resistance in bread wheat (Triticum aestivum L.)

Fusarium head blight (FHB) is one of the most important fungal wheat diseases worldwide. Understanding the genetics of FHB resistance is key to facilitate the introgression of different FHB resistance genes into adapted wheat. The objective of this project was to study the FHB resistance QTL on chromosome 6B, quantify the phenotypic variation, and qualitatively map the resistance gene as a Mendelian factor. The FHB resistant parent BW278 (AC Domain*2/Sumai 3) was used as the source of the resistance allele. A large recombinant inbred line (RIL) mapping population was developed from the cross BW278/AC Foremost. The population segregated for three known FHB resistance QTL located on chromosomes 3BSc, 5A, and 6B. Molecular markers on chromosome 6B (WMC104, WMC397, GWM219), 5A (GWM154, GWM304, WMC415), and 3BS (WMC78, GWM566, WMC527) were amplified on approximately 1,440 F_2:7 RILs. The marker information was used to select 89 RILs that were fixed homozygous susceptible for the 3BSc and 5A FHB QTLs and were recombinant in the 6B interval. Disease response was evaluated on 89 RILs and parental checks in the greenhouse and field nurseries. Dual floret injection (DFI) was used in greenhouse trials to evaluate disease severity (DS). Macroconidial spray inoculations were used in field nurseries conducted at two locations in southern Manitoba (Carman and Glenlea) over two years 2003 and 2004, to evaluate disease incidence, disease severity, visual rating index, and Fusarium-damaged kernels. The phenotypic distribution for all five-disease infection measurements was bimodal, with lines resembling either the resistant or susceptible checks and parents. All of the four field traits for FHB resistance mapped qualitatively to a coincident position on chromosome 6BS, flanked by GWM133 and GWM644, and is named Fhb2. The greenhouse-DS trait mapped 2 cM distal to Fhb2. Qualitative mapping of Fhb2 in wheat provides tightly linked markers that can reduce linkage drag associated with marker assisted selection of Fhb2 and aid the pyramiding of different resistance loci for wheat improvement.     

Characterisation of the gene encoding a protective antigen from Babesia microti identified it as η subunit of chaperonin containing T-complex protein 1

Passive immunisations with a monoclonal antibody termed 1-5H showed a partial but significant inhibition of parasitaemia against Babesia microti challenge infection. By immunoscreening with 1-5H, a clone (termed p58 gene) was obtained from a cDNA expression library of B. microti and the complete nucleotide sequence was determined. A protein homology search showed significant amino acid identities to the η subunit of the chaperonin containing T-complex protein 1 (CCT) of human (59%), mouse (58%) and Plasmodium falciparum (62%). Genomic analyses indicated that the p58 gene is present as a single copy gene and contains a total of approximately 400-bp introns in the genome of B. microti. The mAb 1-5H recognised a 58-kDa protein of B. microti and was found to cross-react with a 60-kDa protein of Babesia rodhaini. These results suggest the possibility that the p58 protein is the CCT η subunit of B. microti and functions as a chaperonin.     

Quantities and types of ectomycorrhizal and endophytic fungi associated with Betula platyphylla var. japonica seedlings during the initial stage of establishment of vegetation after disturbance

Ectomycorrhizal and endophytic fungi of Betula platyphylla Sukatchev var. japonica Hara seedlings were investigated by bioassay using soils from sites where the surface layer had been removed by destructive disturbances. Soil samples were taken from sites A, B, C and D, where 1, 2–3, 4–5, and 7–8 years, respectively had passed since disturbance. Naturally regenerated B. platyphylla var. japonica seedlings grew at sites C and D, but not at sites A or B. The percentages of ectomycorrhizal formation in seedlings were significantly lower in the soils from site A (4%) and site B (13%), compared to those in the soils from site C (53%) and site D (37%). The numbers of ectomycorrhizal morphologic types in sites A, B, C, and D were eight, five, one, and seven, respectively. The same dominant type of ectomycorrhiza was found in sites C and D, and this type was different from those in sites A and B. The frequencies of colonization of seedling roots by endophytic fungi, especially Mycelium radicis atrovirens Melin (MRA) in soils from sites A and B were 31 and 33%, respectively; these frequencies were significantly higher than those for site C (0%) and site D (2%). During the initial stage of establishment of vegetation following disturbance, the quantities and types of ectomycorrhizal fungi in the field that have the potential to associate with B. platyphylla var. japonica might rapidly change after invasion of the host plant. Ectomycorrhizal fungi seemed to compete with endophytic MRA fungi for colonization of the roots of B. platyphylla var. japonica seedlings.     

The development and multiple uses of a standardised bioassay method to select hypocrealean fungi for biological control of aphids

A technically standardised bioassay method was designed, evaluated and used to assess virulence and host range of hypocrealean fungi against aphids. A track mounted sprayer was used to apply conidia because hand held versions of the same sprayer can be used for field applications, thereby allowing the outcome from laboratory experiments to predict activity in the field accurately. Eighteen fungal isolates were assessed in single concentration bioassays against the black bean aphid Aphis fabae Scopoli. Isolates comprised commercially available mycoinsecticides (based on Beauveria bassiana and Lecanicillium longisporum) and isolates of B. bassiana, Lecanicillium spp., Paecilomyces fumosoroseus and Metarhizium anisopliae. Aphid mortality was in excess of 80% for 15 isolates, and HRI 1.72 (L. longipsorum), Z11 (P. fumosoroseus), Mycotech strain GHA (B. bassiana) and ARSEF 2879 (B. bassiana) were studied further. Multiple concentration bioassays identified HRI 1.72 as the most virulent isolate against A. fabae with significantly smaller LC₅₀ and LT₅₀ values compared to other isolates. A precise LC₅₀ value (2.95 × 10² conidia ml⁻¹) was calculated for HRI 1.72 using a second multiple concentration assay with smaller concentrations of conidia. The four isolates were applied at a single concentration (1 × 10⁸ conidia ml⁻¹) against Myzus persicae, A. fabae, Acyrthosiphon pisum, Metopolophium dirhodum, Sitobion avenae and Rhopalosiphum padi. A ranking of aphid susceptibility was obtained, such that S. avenae > M. persicae, A. pisum, A. fabae > R. padi. Results indicate the importance of standardising bioassay methods to reduce bioassay variability without compromising the ability to use the bioassay to investigate fungus–host interactions under varying abiotic and biotic conditions.     

Genetic diversity and relationships between nine species of bamboo in Sri Lanka, using Random Amplified Polymorphic DNA

Random Amplified Polymorphic DNA (RAPD) showed a high degree of polymorphism in nine species of bamboo, Dendrocalamus giganteus Wall ex Munro, D. asper Becker ex K. Heyn, D. longispathus (Kurz) Kurz, Bambusa vulgaris `Striata', B. ventricosa, B. bambos (L.) A. Voss, B. atra Lindley, Gigantochloa atroviolacea Wdjaja and Arundinaria hindsii, in Sri Lanka. The lowest mean genetic distance of 0.143 was between B. vulgaris and B. ventricosa. They could however be distinguished morphologically. The genetic distances separating D. longispathus from D. giganteus and D. asper were both greater than that between the latter two species, which had a value of 0.313. Although the genetic distances between Bambusa vulgaris, B. ventricosa and B. bambos were relatively small, B. atra separated from them at greater distances. The smaller genetic distances between G. atroviolacea and B. vulgaris, B. ventricosa and B. bambos indicated that G. atroviolacea had a closer affinity to these three Bambusa species than B. atra. A. hindsii with the greatest genetic distances from all other species in the study, was not related to any of them. RAPD analysis was useful in determining the genetic diversity and relationships and in detecting problematic generic assignments.