Genetic analysis of a CSR10 (indica) × Taraori Basmati F3 population segregating for salt tolerance using ISSR markers

Segregation for salinity tolerance and ISSR markers based molecular polymorphism were investigated in a F₃ plant population raised via single-seed descent method from a cross between salt-tolerant indica rice variety CSR10 and salt-susceptible premium traditional Basmati rice variety Taraori Basmati HBC19. A total of 130 F₃plants were evaluated individually for salinity tolerance on 1–9 scale on the basis of seedling growth parameters; the average score ranged between 1.7 to 8.3. Frequency distribution curve obtained using the salinity tolerance data of F₃ population and a chi-square analysis, showed a good fit to a normal distribution. Eleven plants each in the category of salt-tolerant and salt-susceptible were selected from the segregating F₃ population for ISSR marker analysis. A total of 149 bands (4–11 bands per primer) ranging from 200 to 3530 bp were scored for the two rice varieties and the selected CSR10 × HBC19 segregating F₃ plants using 26 ISSR primers. Of these, 89 were monomorphic and 60 were polymorphic. Of the 60 polymorphic bands,36 and 20 bands were specific to CSR10 andHBC19 respectively. The remaining four bands were amplified using UBC primers 810,848, 853 and 886 and present in only some of the CSR10 × HBC19 F₃ plants. Notably, ISSR primers with dinucleotide repeat motif and 5'-anchored end amplified more number of bands (7.0 bands/primer) compared to3'-anchored dinucleotide primers (5.4bands/primer), but 3'-anchored dinucleotide primers revealed higher level of polymorphism (2.6 polymorphic bands/primer) compared to 5'-anchoreddinucleotide primers (1.43 polymorphic bands/ primer). While distribution of majority of the polymorphic bands were more or less in the expected ratios in salt-tolerant and/or salt-sensitive F₃segregating plants, but some of the bands amplified using UBC ISSR primers 823, 825,826, 849, 853, 864, 866 and 884 showed highly skewed distribution. Such polymorphic bands stand greater chances of having a linkage with the genes/ QTLs for salinity tolerance and shall be the target for further studies. This revised version was published online in July 2006 with corrections to the Cover Date.     

<Emphasis Type="Italic">Oryza sativa</Emphasis> straw restricts <Emphasis Type="Italic">Phalaris minor</Emphasis> growth: allelochemicals or soil resource manipulation?

Unharvested stubbles or harvested straw of rice (Oryza sativa L.) gets incorporated into soil and interferes with the seedling growth of crop plants. In this paper, we investigated whether rice straw, either through releasing allelochemicals and/or through manipulating soil properties, influences seedling growth of Phalaris minor Retz., a non-native weed largely restricted to wheat (Triticum aestivum L.) fields. One hundred twenty grams of soil was amended with rice straw (0.5, 1, 2, 4, or 6 g/pot) and its effect on fresh shoot biomass of P. minor was examined. Any modification of rice straw phytotoxicity through the use of washed rice straw, activated charcoal, soil sterilization, or nitrogen fertilization was also studied. We carried out chemical and microbial analysis of soils to examine the role of soil properties in influencing P. minor growth. Incorporation of rice straw into soil suppressed the growth of P. minor through modifying soil properties. A dose-dependent increase in total phenolics was observed in soil amended with rice straw. Activated carbon or washing of rice straw, however, could not ameliorate the phytotoxic effects of rice straw. Our results provide initial evidence that rice straw restricts P. minor growth by manipulating soil chemical and microbiological properties. Authors contributions IJ conceived of and supervised the study, and wrote the paper; SK carried out the work.     

Organochlorine insecticide residues in the rain water in Delhi,India

Rain water samples were regularly collected from three sites, namely, Netaji Nagar, Moti Nagar and Town Hall within the Delhi city area from July, 1980 to June, 1982. The pesticide residues were adsorbed on polyurethane foam coated with 0.5 % DC-200 and subsequently extracted and analyzed for DDT, HCH and their metabolites/isomers. The concentration of total DDT ranged from 0.22 to 108 μg L^?1 with a mean value of 12.5 μg L^?1. The samples of rain water contained varying levels of 4,4-DDT, 2,4-DDT, 4,4-DDE, and 4,4-DDD. The 4,4-DDT, 4,4-DDE and 2,4-DDT were the main components of total DDT. The range of HCH residues in rain water was from 0.08 to 43 μg L^?1 with a mean of 5.3 μg L^?1. The residues of HCH consisted mainly of α- and γ-isomers with traces of β and δ-isomers. The α- and γ-isomers accounted for 76 and 24% of total HCH, respectively. The concentrations of DDT and HCH in rain water were generally less than 10 μg L^?1 and exceeded 10 in only 4 and 3 cases, respectively. The residues of these insecticides were generally higher during October to December. Residues of DDT were higher at Moti Nagar which is near a DDT factory. Residues of HCH were maximum at Town Hall, a commercial area of the city.     

Efficacy of N2O2 donor schiff bases and their Zn2+ complexes on various morphological and biochemical parameters of Cicer arietinum L.

Schiff-base polydentate ligands types of salen and salophen can form stable complexes with Zn²⁺ and these metal complexes can act as a source of zinc (Zn) to plant's body if they are used as micronutrient supplements. Inspired by these facts, four different Schiff-base ligands and their Zn²⁺ complexes were first synthesized and then characterized by different analytical and spectroscopic techniques. To investigate their effects local chickpea seeds were treated with each ligands and complexes and different morphological and biochemical parameters were monitored. Among all the complexes and ligands it was found that the C4 complex, that is, [N,N'-(o-phenylene)bis-(3-methoxysalicylidenediamine)] monohydrate showed the maximum efficacy when treated as a micronutrient supplement for Cicer arietinum L. So that these complexes especially the C4 can act as an potential source of Zn.     

Protection of mice against <Emphasis Type="Italic">Brucella abortus 544</Emphasis> challenge by vaccination with recombinant OMP28 adjuvanted with CpG oligonucleotides

Brucella abortus, a gram negative, facultative intracellular pathogen causes brucellosis in many animal species and humans. Although live, attenuated vaccines are available against this infection, they suffer from certain limitations. Therefore, the development of an effective subunit vaccine against brucellosis is an area of intense research. The outer membrane proteins (OMPs) of Brucella species have been extensively studied for its immunogenicity and protective ability. We have investigated the potential of CpG ODN to enhance the immunogenicity and protective efficacy of recombinant 28 kDa outer membrane protein (rOMP28) of Brucella melitensis. The study demonstrated vigorous immunoglobulin G (IgG) response of OMP28. The administration of rOMP28 with CpG caused increased cell mediated immune response in terms of induced IgG2a, T-cell proliferation and up-regulation of type I cytokine expression. In contrast, the free antigen suppressed the interferon gamma (type I cytokine) production on in-vitro stimulation of spleenocytes. The result indicates the role of OMP28 in the down regulation of IFN-γ production. Moreover, the B. abortus S-19 vaccinated mice showed highest production of IL-4 and IFN-γ. The protective ability of the antigen was evaluated by systemic bacterial clearance after challenging the mouse with B. abortus 544 pathogen. The level of protection was significant in rOMP28+CpG treated mice but was lower than the required level. The results of the present study indicate that rOMP28 could be an immunogen capable of inducing both humoral and cellular immune response. The humoral response was biased towards Th1 type when it was co-administered with CpG.     

Effect of herbicides with different modes of action on physiological and cellular traits of Anabaena fertilissima

Cyanobacteria are important components of the lowland rice ecosystem. Therefore, it is important to examine the effect of herbicides (commonly used against weeds of rice crop) on the performance of cyanobacteria. We studied the toxic effects of three herbicides often used in rice field, viz. propanil, pretilachlor and glyphosate, on the performance traits of Anabaena fertilissima C.B. Rao. Pretilachlor [0–40 active ingredient (ai) mg/L] and glyphosate (0–80 ai mg/L) exhibited toxicity to A. fertilissima at higher doses than propanil (0–1.5 mg/L). Propanil had severe damaging effects on cellular characteristics of A. fertilissima when compared to pretilachlor or glyphosate. Propanil treatment of A. fertilissima resulted in the leakage of protoplast from the heterocyst due to the breakage of the plasma membrane and surrounding wall. Our study shows that photosystem II herbicides such as propanil could have deleterious effects on phototrophic (cyanobacterial) communities, which are an integral part of the rice ecosystem.     

Photostabilization of quinalphos by crystal violet on the surface of kaolinite and palygorskite

Photochemical stability of the insecticide, quinalphos (O,O-diethyl O-quinoxalin-2-yl phosphorothioate), adsorbed on kaolinite and palygorskite was studied. In all cases considerable photostabilization was achieved in comparison with the sample of pesticide in its free form. Improvement of photostabilization was achieved when a cationic dye (crystal violet) was co-adsorbed with the quinalphos. The interactions between quinalphos and clays were studied by Fouriertransform infra-red spectroscopy. It is suggested that photostabilization is due to steric hindrance imposed by the clay surface to the isomerization step of photochemical reaction and pacification of clay surface by crystal violet.     

The effects of prednisone and azathioprine on circulating immunoglobulin levels and lymphocyte subpopulations in normal dogs.

This study investigates serum immunoglobulin (SIg) levels and lymphocyte subpopulations in normal dogs in response to putative immunosuppressive doses of prednisone and/or azathioprine. The objectives were to quantify SIg levels and lymphocyte subpopulations, including Thy-1+, CD4+, CD8+ and B cells, in normal dogs both before and after the administration of prednisone and/or azathioprine at 2 mg/kg, PO, each. Eighteen beagles were divided into 3 groups of 6 dogs each. Blood samples for radial immunodiffusion assay of IgG, IgM and IgA, complete blood count (CBC)and flow cytometry were collected prior to the administration of any drugs and again after 14 d of azathioprine, prednisone or azathioprine and prednisone. Peripheral blood mononuclear cells were isolated using density centrifugation and were incubated with monoclonal antibodies reacting with CD4+, CD8+, Thy-1+ and membrane immunoglobulin. Lymphocyte subsets were quantified using flow cytometry. Azathioprine-treated dogs had no significant changes in SIg levels or lymphocyte subpopulations. Prednisone-treated dogs had significant (P < 0.05) decreases in all SIg levels, all lymphocyte subpopulations and erythrocyte numbers, and had an increase in neutrophil counts. Prednisone and azathioprine-treated dogs had significant (P < 0.05) decreases in serum IgG levels and Thy-1+ and CD8+ lymphocyte subpopulations, with an increase in the CD4:CD8. These dogs also had a significant decrease in erythrocyte number and a significant increase in the monocyte count. These findings suggest that azathioprine and prednisone in combination or prednisone alone may be useful for the treatment of T cell-mediated diseases since decreased circulating T cell levels were demonstrated following treatment. The combination of drugs or azathioprine alone may not be appropriate for treatment of acute or autoantibody-mediated immune disease, because SIg levels were minimally affected by treatment.     

Porcine intestinal epithelial cell lines as a new in vitro model for studying adherence and pathogenesis of enterotoxigenic Escherichia coli

Enterotoxigenic Escherichia coli (ETEC) infections result in large economic losses in the swine industry worldwide. The organism causes diarrhea by adhering to and colonizing enterocytes in the small intestines. While much progress has been made in understanding the pathogenesis of ETEC, no homologous intestinal epithelial cultures suitable for studying porcine ETEC pathogenesis have been described prior to this report. In the current study, we investigated the adherence of various porcine ETEC strains to two porcine (IPEC-1 and IPEC-J2) and one human (INT-407) small intestinal epithelial cell lines. Each cell line was assessed for its ability to support the adherence of E. coli expressing fimbrial adhesins K88ab, K88ac, K88ad, K99, F41, 987P, and F18. Wild-type ETEC expressing K88ab, K88ac, and K88ad efficiently bound to both IPEC-1 and IPEC-J2 cells. An ETEC strain expressing both K99 and F41 bound heavily to both porcine cell lines but an E. coli strain expressing only K99 bound very poorly to these cells. E. coli expressing F18 adhesin strongly bound to IPEC-1 cells but did not adhere to IPEC-J2 cells. The E. coli strains G58-1 and 711 which express no fimbrial adhesins and those that express 987P fimbriae failed to bind to either porcine cell line. Only strains B41 and K12:K99 bound in abundance to INT-407 cells. The binding of porcine ETEC to IPEC-J2, IPEC-1 and INT-407 with varying affinities, together with lack of binding of 987P ETEC and non-fimbriated E. coli strains, suggests strain-specific E. coli binding to these cell lines. These findings suggest the potential usefulness of porcine intestinal cell lines for studying ETEC pathogenesis.