Isolation and identification of Serratia marcescens Ha1 and herbicidal activity of Ha1 ‘pesta’ granular formulation

A total of 479 bacterial strains were isolated from brine(Bohai, Qinhuangdao City, Hebei Province, China). Bioassay results indicated that 4 strains named Ha1, Ha17, Ha38, and Ha384 had herbicidal activity. And strain Ha1 had the highest effective herbicidal activity. As a result, this study aims to identify strain Ha1, characterize its physiological and biological activities, evaluate the herbicidal activity of its metabolites, and develop a ‘pesta' formulation and assess its effectiveness on Digitaria sanguinalis. Ha1 was identified as Serratia marcescens based on 16 S r DNA sequencing. This strain has a flagellum, a diameter of 0.5 to 0.8 μm, and a length of 0.9 to 2.0 μm. The indole test shows positive results, and the catalase enzyme exhibits strong positive reactions. Results further showed that the inhibitory concentration(IC50) of the crude extracts to D. sanguinalis radicula and coleoptile were 3.332 and 2.828 mg m L–1, respectively. Both the suppression of D. sanguinalis and the cell viability of the Ha1 formulation in ‘pesta' were higher when stored at 4°C than at(25±2)°C. These results indicated that S. marcescens Ha1 can potentially be used as a biocontrol agent against D. sanguinalis.     

Promotion and Inhibition of Ruminal Epithelium Growth by Butyric Acid and Insulin-Like Growth Factor-1（IGF-1） in Dairy Goats

Isolated ruminal epithelia from caudal blind sacs of dairy goats were incubated with butyrate and insulin-like growth factor-1（IGF-1） at different concentrations. Proportions of ruminal epithelium in different phases of the cell division cycle were determined by flow cytometric analysis. The proportion of epithelial cells in S phase and G2-M phase（PS＆G2-M） increased significantly（P〈0.01） whereas the proportion of epithelial cells in G0-G1 phase（PG0-G1） decreased after incubation with IGF-1. PS＆G2-M decreased whereas PG0-G1 increased markedly（P〈0.01） after incubation with sodium butyrate. PS＆G2-M incubated with IGF-1 and butyrate sodium together increased more than that incubated with IGF-1 alone; PG0-G1, however, decreased significantly（P〈0.01）. Our results indicate that IGF-1 enhances whereas sodium butyrate inhibits the proliferation of rumen epithelial cells. Furthermore, butyrate and IGF-1, together, have a synergic effect on the proliferation of rumen epithelium.     

Isolation and Biological Characteristics of Photosynthetic Bacterium Strain PSB-1

Photosynthetic bacteria(PSB) with multiple functions of applying photo-energy and complex metabolism, are widely spread in lakes, rivers and seas. According to Bergey's manual of systematic bacteriology, the PSB includes at least 27 genera[1]. In recent years, some new species of PSB have been reported The study of PSB is of high value in theory and practice. Some new biochemical compounds derived from PSB are discovered with the potentiality of insecticide, fungicide, herbicide and bacteriacide[8,9].PSB can also be applied to the control of environment,and industries of energy and feed.[8,9,10]     

Correlation Analysis on Single Nucleotide Polymorphism of CAPN1 Gene and Meat Quality and Carcass Traits in Chickens

The selection of meat quality has received considerable focus in chicken breeding. This study was aimed at investigating the effect of CAPN1 gene on meat quality traits in chicken populations. Primer pairs for 3 UTR in CAPN1 were designed from database of chicken genomic sequence. Polymorphisms were detected using PCR-SSCP and DNA sequencing. A mutation at position 9 950 nt （G/A, locus A） was found among individuals in each population. The allele and genotype frequencies significantly differed among eight lines with higher frequencies of allele A2 and genotype AIA2 （P〈0.01）. The least square analysis showed that there was significant difference （P 〈 0.05） in muscle fiber density and some carcass traits among genotypes and that the breast muscle fiber density （BFD） of birds ofAIA1 genotype was significantly higher （P〈0.05） than that of birds ofA2A2 genotype. It was concluded that the CAPN1 gene was the major gene affecting the muscle fiber traits of chicken or was linked with the major gene. These results were useful for studying the molecular mechanism that influences meat traits and were used as the base of molecular-assisted selection to meat quality traits. So, this site may be a potential marker affecting the muscle traits of chickens.     

Interactions Ticks,Hosts and Pastures： Case of the Girolando Dairy Cattle and the Artificial Pastures of Panicum maximum and Panicurn maximum var. C1

On the Kpinnou ranch in Benin, it was observed that the Girolando dairy cattle which graze Panieum maximum var. CI are more susceptible to infestation of ticks. The purpose of this study was to highlight the interactions between ticks and their bovine hosts and two types of artificial grazing pastures. Nineteen young Girolando dairy cattle were used during the big rainy season （March-June） 2009. All present ticks on the animals have been counted according to the body region. The bovine have been divided into two relatively homogeneous groups often and nine animals. The group I of 10 animals had been grazed on Panicum maximum whereas the group 2 of 9 animals had been grazed on Panicum maximum var. C 1. During the two months of grazing, a weekly monitoring of the evolution of the load in ticks has been achieved. Four genera of ticks were identified on the bovine Girolandos （Amblyomma, Hyalomma, Rhipicephalus and Boophilus）. The Boophilus genus is the most abundant （P 〈 0.05）. The animals having grazed Panicum maximum var. C I are more infested than those that have been grazed Panicum maximum. A variation of the rate of infestation of the animals has been observed in relation to the different body areas. The colour of the coat also has an effect on the load in tick of the bovine. The bovine of dark coat are in general more infested （P 〈 0.05） than those of clear colour.     

Correlation Analysis of Rice Seed Setting Rate and Weight of 1 000-Grain and Agro-Meteorology over the Middle and Lower Reaches of the Yangtze River, China

The purpose of this study is to reveal the effects of historic climate change on rice yield over the middle and lower reaches of the Yangtze River, China, and to better adapt to climate change in the future. This study presents the relation of temperature and precipitation and rice components from 1981 to 2003 at 48 early rice stations and 30 middle rice stations. It focuses on an analysis of three stages： flowering, pre-milk, and late milk. The results show that mean maximum temperature and mean daily precipitation at the stages of flowering and pre-milk are most related to early rice yield. Yield change of middle rice is mainly because of mean precipitation change at the flowering stage. Furthermore, percentage of undeveloped grain increases as mean maximum temperature rises at the flowering stage. Over-precipitation in the reproductive stage is a major reason for reduction in yield of early rice. Consecutive rainfall and continuous high temperature can have negative effects on middle rice yield. Global warming would affect middle rice more seriously than early rice.     

Cloning and Sequence Analysis of Glycoprotein D Gene of Bovine Herpesvirus-1 Strain Luojing

By means of PCR,the gene encoding gD of bovine herpesvirus-1 (BHV-1) strain Luojing was amplified,cloned and sequenced. The nucleotide sequence of this gD gene was 1 251 bp,encoding 417 amino acids. Comparied with the published P8-2 strain ,the homology of the necleotide sequence is 99.92%,and that of the deduced amino acid sequence is 100%. The results indicated that gD of BHV-1 was highly conservative.     

Type 1 interferons and the virus-host relationship: a lesson in détente

The interface between an infectious agent and its host represents the ultimate battleground for survival: The microbe must secure a niche for replication, whereas the host must limit the pathogen's advance. Among the host's arsenal of antimicrobial factors, the type 1 interferons (IFNs) induce potent defense mechanisms against viruses and are key in the host-virus standoff. Viruses have evolved multiple tricks to avoid the immediate antiviral effects of IFNs and, in turn, hosts have adapted use of this innate cytokine system to galvanize multiple additional layers of immune defense. The plasticity that exists in these interactions provides us with a lesson in détente.     

Population Dynamics and Survival of Rhizoctonia solaniAG-1 in Field Soil Under Rice-Wheat Rotation

A field under rice-wheat rotation was selected near Chengdu, China, to study the population of Rhizoctonia solani anastomosis group 1 (AG-1), pathogen causing rice sheath blight disease, in natural soil ecosystem. Inocula of the fungus recovered from the field were divided into three types, i.e., sclerotia, free mycelium retained in the soil passed through a 0.355mm sieve, and colonized plant debris which was subdivided into small colonized debris retained between 2.00 and 0.355mm sieves and large colonized debris retained on 2.00mm sieve after wet screening. Quantitative estimation of the three types of inocula in one year indicated that small colonized debris was the dominant inoculum type for most of the time. The population peaked in March and September at 1 210 and 480 colonized debris i00 g^-1 air-dry soil respectively, and fell down in December and August to 0 and 177 colonized debris 100 g^-1 air-dry soil respectively. Free mycelium was only detectable in March, September and October with 1 209, 7.9 and 14.5 μg fresh wt myceliumg^-1 air-dry soil respectively, which corresponded to the two peaks and the second highest level of small debris density in the year. Viable sclerotia and large colonized debris were rare with populations ranging from 0 to 3 for sclerotia and 0 to 14 for large colonized debris 100 g^-1 air-dry soil, but were the main structures to survive over winter. It was expected that soil temperature was the main factor determining population dynamics of R.solani AG-I in natural soil. Optimum temperature for population increasing is predicted to be around 15℃, with a range from i0 to 25℃. Viability tests indicated that 60.9% sclerotia could survive after 265 d being buried in natural sandy loam in field conditions in Beijing, while colonized rice straw debris (0.5 - 1.0 cm long) could not yield the fungus on medium plates after 88 d of being buried under the same conditions.     

Comparison of Growth and Development Patterns of Fenneropenaeus chinensis (Osbeck) Huanghai No.1 and the First Generation of Wild Population

[Objective] The aim was to estimate the developmental characteristics of Huanghai No.1 and the first generation of wild population in Fenneropenaeus chinensis for providing a reference for the development, feeding management and breeding. [Method] Four growth models were used to fit the growth patterns of 15 morphological traits. The squared multiple correlation coefficient (R2 ) of the Cubic growth model was higher than the other three models, so it was selected to investigate the growth pattern and age in month at inflexion. [Result] Ages in month at inflexion of body weight in Huanghai No.1 and the G1 population were 2.87 (body weight at inflexion was 14.98 g) and 4.05 (body weight at inflexion was 26.26 g), respectively. In addition, Ages in month at inflexion of morphological characters in Huanghai No.1 were from 0.51 to 3.07. CL had the most rapid growth rate, followed by AW, CH, AH, CW, BL, FL, AL5, AL3, AL4, TL, AL2, AL1, and AL6. Ages in month at inflexion in the G 1 population were from 2.38 to 3.08, except that of AL2, and the order of achieving the most rapid growth rate was AL2, AL1, AL3, AL4, CH, AL5, CW, FL, AH, AW, TL, CL, BL, and AL6, that delayed one month than that of Huanghai No.1 except AL2 and AL1. [Conclusion] The development of Huanghai No.1 cultivar was advanced for about one month compared to that of the G1 population.     

Purification of Aminopeptidase N Protein and Differences in cDNAs Encoding APN1 Between Susceptible and Resistant Helicoverpa armigera Strains to Bacillus thuringiensis Toxins

The brush border membrane vesicles (BBMVs) in midgut of Helicoverpa armigera were successfully separated, and most of the Aminopeptidase N (APN) activities in BBMV were preserved. The 3-[(3-chlor-amidopropyl) dimethylammonio]-l-propane-sulphonate (CHAPS) can enhance the dissolution of BBMV, and phosphatidylinositol-specific phosopholipase C (PI-PLC) can cleave the APN from midgut membrane. The APN was primarily purified using a Mono-Q column. The results of immunoblotting showed that the 120 and 170 kDa proteins in the BBMV could bind CrylAc, and 120 kDa APN was a glycosylphosphalidylinositol(GPI)-anchored protein. Two Bt-resistant strains (Bt-P, Bt-M) were obtained after being selected for more than five years in laboratory using Bt insecticides and Bt transgenic cotton incorporated into diet separately. The resistance of Bt-P and Bt-M were 1 083.3 and 48.7 times that of susceptible strain. The genes encoding APNI in midgut of susceptible and resistant H.armigera were cloned by PCR and RACE techniques. The inferred amino acid sequences of APNI possessed the common character of APN family in insects. In comparison with APNI in susceptible strain, three nucleotide mutations were observed in the APNI of Bt-M strain and resulted in two amino acid replace in the putative protein sequences, and eight nucleotide mutations were observed in Bt-P strain and resulted in five amino acid replace.     

Phylogeny and biodiversity of Trichoderma and Hypocrea and its implications on taxonomy

Safe strain identification and species recognition is an important issue for Trichoderma and Hypocrea, because members of the genus are economically important producers of industrial enzymes and antibiotics, have application as biocontrol agents against plant pathogens, whereas some have become known as opportunistic pathogens of immunocompromised mammals and humans. However, classical approaches based on the use of morphological and phenetic characters have been difficult to apply, due to…     

The Effects of Dwarfing Genes （Rht-B1b,Rht-D1b,and Rht8） with Different Sensitivity to GA3 on the Coleoptile Length and Plant Height of Wheat

Understanding the effects of wheat dwarfing genes on the coleoptile length and plant height is crucial for the proper utilization of dwarfing genes in the improvement of wheat yield. Molecular marker analysis combined with pedigree information were used to classify wheat cultivars widely planted in major wheat growing regions in China into different categories based on the dwarfing genes they carried. The effects of the dwarfing genes with different sensitivity to gibberellins （GA3） on the coleoptile length and plant height were analyzed. Screening of 129 cultivars by molecular marker analysis revealed that 58 genotypes of wheat contained the dwarfing gene Rht-B1b, 24 genotypes of wheat contained Rht-D1b gene and 73 genotypes of wheat possessed Rht8 gene. In addition, among these 129 cultivars, 35 genotypes of wheat cultivars contained both Rht-B1b and Rht8 genes and 16 genotypes of wheat cultivars contained both Rht-D1b and Rht8 genes. Wheat cultivars with the dwarfing genes Rht-B1b or Rht-D1b were insensitive to GA3, while the cultivars with the dwarfing gene Rht8 were sensitive to GA3. Most of the wheat genotypes containing combination of Rht8 gene with either Rht-B1b or Rht-D1b gene were insensitive to GA3. The plant height was reduced by 24.6, 30.4, 28.2, and 32.2%, respectively, for the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋ Rht8, and Rht-D1b ＋ Rht8 genes. The plant height was reduced by 14.3% for the wheat cultivar containing GA3-sensitive gene Rht8. The coleoptile length was shortened by 25.4, 31.3, 28.4 and 31.3%, respectively, in the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋Rht8 and Rht-D1b ＋ Rht8 genes, while the coleoptile length was shortened only by 6.2% for the wheat cultivar containing Rht8 gene. We conclude that GA3-insensitive dwarfing genes （Rht-B1b and Rht-D1b） are not suitable for the wheat improvement in dryland because these two genes have effect on reducing both plant height and coleoptile length. In contrast, GA3- sensitive dwarfing gene （Rht8） is a relatively ideal candidate for the wheat improvement since it significantly reduces the plant height of wheat, but has less effect on the coleoptile length.     

Bacterial Expression and Purification of an Active ω-Atracotoxin-Ar1b from Spider Atrax robustus

The ω-atracotoxin-Ar1b toxin(ω-ACTX-Ar1b)is one of the arthropod-selective peptide neurotoxins from the venom of Australian funnel-web spider Atrax robustus.The gene of Ar1b was synthesized and cloned into pET-32a(+)vector to allow expression of Ar1b as a fusion protein with thioredoxin and the His-tag(rTrx-Ar1b)in E.coli BL21(DE3).The optimal condition for inducing the expression of rTrx-Ar1b was 1.0 mmol L-1 IPTG for 6 h at 28℃.The fusion protein rTrx-Ar1b was expressed in soluble form and was purified effectively by His Trap HP affinity column and rpHLPC and a final yield of purified rTrx-Ar1b was 95 mg from 1000 mL E.coli culture.The LD50 values for Mythimna separate and Tenebrio molitor were 111.66 and 11.04 μg g-1 determined by injection of the purified rTrx-Ar1b.The results indicated that the recombinant Ar1b protein was successfully expressed in E.coli and it was high toxicity against tested insects.