Development and release of a malacosporean (Myxozoa) from Plumatella repens (Bryozoa: Phylactolaemata)

During an experiment to transmit Tetracapsula bryosalmonae Canning, Curry, Feist, Longshaw et Okamura, 1999 to a laboratory-cultured bryozoan, Plumatella repens L. a previously undescribed malacosporean species was noted. This parasite produced sacs of spores in the host that reached 1.2 mm in length. The spores released from the sacs appeared similar in size to the two species of Tetracapsula previously described although slight differences in form were noted. Release of spores from the bryozoans was observed associated with the lophophore of the host. The use of experimental bryozoan cultures for the examination of malacosporeans is described and discussed.     

Improved control of clubroot (Plasmodiophora brassicae) by a mixture of a fungicide and a plant defense inducer

Journal of Plant Diseases and Protection - The mixtures of 10 % cyazofamid SC and 25 % methiadinil SC were selected at different concentrations in root irrigation treatment of...     

Longevity of a mixture of acetamiprid and bifenthrin (Transport(TM) ) at the termiticidal application rate

BACKGROUND: The 30 month longevity, mobility and insecticidal activity of a combination of acetamiprid and bifenthrin currently marketed in the United States for the prevention of termite infestation in buildings was investigated in greenhouse and laboratory studies. RESULTS: Acetamiprid dissipated to below the limit of detection within 7 months of application, while bifenthrin remained in the soil at levels sufficient to kill termites for the duration of the study. Acetamiprid was detected in decreasing amounts in eluates of treated soil from months 1 to 4, while no bifenthrin was detected in eluates at any time. The treated soil remained toxic to termites for the 30 month duration of the study. Two indices of synergy between technical‐grade acetamiprid and bifenthrin demonstrated that it is unlikely that there would be any synergism between the two active ingredients in the field. The presence of vegetation did not have a significant effect on the longevity of bifenthrin, except at intermediate times, where residues in the treated soil were higher in vegetated plots, depending on depth and time. CONCLUSIONS: Acetamiprid has a short residual time in soil, and this formulation's effectiveness beyond about 7 months against subterranean termites is due to the bifenthrin content. Copyright © 2011 Society of Chemical Industry     

Population flux and mortality in a ragwort (Senecio jacobaea L.) infestation

Actuarial data on the progress through the life-cycle and the death of individual plants of Senecio jacobaea in permanent pasture were obtained over a period of one year by repeated mapping of all the plants in twenty permanent quadrats. The data were used to construct a model of population flux and mortality in a hypothetical population in which germination, maturation and death were constant from year to year and equal to those in the real population in the year of study. In the hypothetical population 57% of all plants died as seedlings. 35% as vegetative rosettes and 8% immediately after flowering. Of plants which flowered in the first 2 years or survived into a third year 8% were annuals or winter annuals, 39% were biennials and 53% were perennials.     

Phyllonorycter apparella, a new record and a new pest of trembling aspen (Populus tremula) in Turkey

Phyllonorycter apparella (Herrich-Schäffer, 1855) (Lepidoptera: Gracillariidae) is a new record for the Turkish fauna and a new trembling aspen(Populus tremula L.) pest for Turkey. Its biology, damage and infestation ratio were studied in Sankami?. (Kars), Turkey, during 1996 and 1997.P. apparella has one generation a year. The developmental stages of the pest are described briefly. P.apparella hibernates in the adult stage. At the beginning of June, the adults appear. Females deposit their eggs on both leaf surfaces, generally one by one, 7–10 days after emerging. The early instars (sap-feeding larvae) start to mine mostly from the underside of leaves. Each mine has one larva, and each leaf may have up to 26 mines. The last instar (tissue-feeding larva) begins to pupate in the mine after mid August. The adults emerge from mid September to the beginning of October, and move to the trunks of old pine trees, where they hibernate in bark crevices. The infestation level may be as high as 90% of the leaves on some trees.     

Inhibition of chitinolytic enzymes from Streptomyces griseus (bacteria), Artemia salina (crustacea), and a cell line from Chironomus tentans (insecta) by allosamidin and isoallosamidin

The influence of allosamidin and its diastereoisomer isoallosamidin on chitinase activity from an insect cell line of Chironomus tentans, the crustacean Artemia salina and the bacterium Streptomyces griseus was studied. The rank order of susceptibility of chitinase activity to both inhibitors was found to be: insects »crustaceans« fungi, although isoallosamidin is about 600-fold (insect) or 400-fold (crustacea) less active than allosamidin and does not inhibit chitinase from Streptomyces at all. The complete and exclusive inhibition of N-acetyl-β-D-glucosaminidase by an acetylgluconolactone-derivative and chitinase activity by allosamidin indicates that both enzymes can be determined separately in crude extracts, (containing both enzymes), with the substrates 4-methylumbelliferyl-N-acetylglucosaminide or 4-methylumbelliferyl-chitoriose, respectively.     

TransgenicNicotiana Benthamiana and grapevine plants transformed with grapevine virus a (GVA) sequences

As part of a project to construct virus-resistant transgenic grapevines, grapevine virus A (GVA) coat protein (CP) sequences were introduced into grapevine and the model plantNicotiana benthamiana. The engineered constructs were tested for their ability to engender resistance inN. benthamiana. A number of GVA-CP-transformedN. benthamiana lines have become resistant to GVA. Preliminary biological and molecular analyses strongly suggest that in most cases the obtained resistance is RNA-mediated. Several lines of transgenic grapevine were obtained.     

克幼脲对玉米螟的毒力和药效测定

本文研究了苯甲酰基苯脲类化合物克幼脲对玉米螟的毒力及药效。室内测定表明，克幼脲对玉米螟低龄幼虫的胃毒毒力ＬＣ_５０＝２．３９ｍｇ／ｋｇ，对玉米螟卵也表现了一定的抑制效应；田间试验证明，克幼脲复配４号对玉米螟的防效达９４．２％。     

Isolation and Characterization of a New Virulence Gene (abvA) of Agrobacterium tumefaciens

A mutant (M-1) was isolated by transposon (Tn5) insertion mutagenesis of Agrobacterium tumefaciens (strain A-208, C58 chromosome, nopaline type T37 pTi, virulent). The M-1 mutant exhibited a complete avirulent phenotype on Kalanchoe daigremontiana leaf and Kalanchoe pinnata stem but a very attenuated virulent phenotype on root of Daucus carota. The mutant had one insertion of Tn5 in pTi. A wild-type target segment (2.3 kb) that included the site of Tn5 insertion in M-1 mutant was cloned. Introducing the 2.3 kb segment into M-1 complemented completely the avirulent phenotype, producing galls as big as strain A-208. The 2.3 kb segment was sequenced, identifying three open reading frames, ORF 1 (354 bp), ORF 2 (261 bp) and ORF 3 (801 bp) in the segment. A Tn5 was inserted between the third and fourth nucleotide of ORF 1 in M-1. The ORF 1 had no homology to any reported genes and thus was named the abvA gene. The ORF 3 had the high homology (identities 44%, positive 68%) to the gene of the sarcosine oxidase β subunit (accession no. sp/P40875). Introduction of the DNA segment (743 bp) containing the abvA gene and its promoter region into M-1 partially complemented the avirulent phenotype of the mutant, producing galls smaller than strain A-208. The abvA gene was distributed not only on nopaline-type pTi (T37) but also on octopine-type pTi (A6NC) and chromosome (C58) of A. tumefaciens. M-1, being avirulent on K. daigremontiana and K. pinnata, had a Tn5 insertion only in the abvA gene on pTi but not in the abvA gene on the chromosome, implying that the abvA gene on the chromosome in strain A-208 is not functional. A binary vector, pIG121-Hm, containing the β -glucuronidase (GUS) gene with an intron was introduced into M-1, which was then applied to leaves of K. daigremontiana to assay GUS activity for monitoring T-DNA transfer to the host nucleus. High GUS activity comparable to that in strain A-208 was detected in M-1 in spite of its inability to induce galls, suggesting that M-1 can transfer T-DNA into the host nucleus, but cannot integrate it into the chromosome. Received 25 October 2000/ Accepted in revised form 28 December 2000     

EK-2612, a new cyclohexane-1,3-dione possessing selectivity between rice (Oryza sativa) and barnyardgrass (Echinochloa crus-galli)

A newly synthesized experimental compound, EK-2612 is one of the class of cyclohexane-1,3-diones which are commonly known to be grasskillers. A greenhouse study was conducted to evaluate the herbicidal performances of EK-2612 on several grass species in comparison with tralkoxydim, a commercialized cyclohexanedione derivative. Like tralkoxydim, the compound EK-2612 showed excellent control efficacy on most grass weeds tested through foliar application rates between 250 and 63 g AI ha(-1). Unlike tralkoxydim, however, EK-2612 showed a good rice safety, and there was no rice damage observed at the level below 125 g AI ha(-1), while rice injury developed at the same application rates of tralkoxydim. With this rice safety, EK-2612 controlled barnyardgrass effectively up to the two-leaf stage under both submerged and dried paddy conditions. An in vitro ACCase assay indicated that EK-2612 is a strong ACCase inhibitor; however, the dose-response was not substantially different in rice and barnryardgrass, showing I50 values of 0.1 and 0.12 microM, respectively. These results suggest that the compound EK-2612 is targeting plant ACCase, but the whole-plant rice safety is not attributable to a different inhibition of the target site in rice from that in barnyardgrass.     

Occurrence and molecular characterization of Actinidia virus C (AcVC), a novel vitivirus infecting kiwifruit (Actinidia spp.) in China

Kiwifruit (Actinidia spp.) is an economically important fruit crop in the world. China is the largest producer of kiwifruit in terms of both acreage and yield. In this study, a novel virus, tentatively named Actinidia virus C (AcVC), was discovered in Actinidia deliciosa ‘Xuxiang’ grown in commercial kiwifruit fields in the Shaanxi province, a major kiwifruit-growing region in China. Sequencing of the complete genome showed that AcVC has 7,668 nucleotides (not including the poly-(A) sequence). Complete genome comparison and phylogenetic analysis showed that AcVC is most closely related to AcVA and then to AcVB. AcVC shares 69.2% nucleotide identity with AcVA (GenBank accession number JN427014 ). Based on these data, Actinidia virus C is assigned as a new tentative member of the genus Vitivirus in the family Betaflexiviridae. AcVC was found to infect A. deliciosa and A. chinesis, the two major cultivated kiwifruits. Infection frequency of AcVC varied with the kiwifruit-growing regions and cultivars in the Shaanxi province of China.     

橘小实蝇一种重要的寄生蜂-凡氏费氏茧蜂

橘小实蝇寄生蜂凡氏费氏茧蜂Fopius vandenboschi(Fullaway)隶属膜翅目小茧蜂科潜蝇茧蜂亚科,是田间控制橘小实蝇的优势蜂种,在国外田间控制橘小实蝇已获得巨大成功,而国内应用寄生蜂田间控制橘小实蝇尚属空白。本研究室在研究中发现田间已有凡氏费氏茧蜂F.vandenbosch定殖,并室内繁殖成功。本文详细地描述了该寄生蜂的特征,旨在为田间应用奠定基础。