Uticaj tehnologije gajenja na prinos ozime pšenice

This paper deals with result of the effects of different technologies on grain yield of winter wheat in investigated period (1999/00-2001/02) on the chernozem luvic soil type. Tillage systems and fertilization with nitrogen fertilizers in applied technologies have a big influence on grain yield of winter wheat. The results of our investigation show that yield grain of winter wheat was higher 11.65% in technologies which included mulch tillage system then conventional technologies. Technology with no tillage system decreased grain yield of winter wheat. Amounts of inorganic nitrogen fertilizers as main factor have effect on the grain yield of winter wheat. Grain yield increased with the level of inorganic nitrogen.U radu je ispitivan uticaj tri tehnologije gajenja ozime pšenice (konvencionalne i dve konzervacijske) na prinos zrna ozime pšenice sorte Pobeda. Ispitivanje je obavljeno na "Radmilovcu" eksperimentalnom dobru Poljoprivrednog fakulteta u Zemunu na zemljištu tipa izluženog černozema u trogodišnjem periodu (1999/2000-2001/2002. g.). Tehnologija gajenja ozime pšenice koja uključuje konzervacijski sistem obrade zemljišta sa čizel plugom i različitim nivoima prihranjivanja azotom pokazao je niz prednosti u odnosu na tehnologiju gajenja sa konvencionalnom obradom raoničnim plugom i u odnosu na tehnologiju gajenja sa direktnom setvom. Najveći prinosi ozime pšenice dobijeni su u tehnologiji gajenja sa konzervacijskom obradom zemljišta. Prinos zrna pšenice u tehnologiji gajenja sa zaštitnom obradom zemljišta bio je značajno veći u trogodišnjem proseku za 11.65% od prinosa u konvencionalnoj tehnologiji, a vrlo značajno veći za 26.17% od konzervacijske tehnologije gajenja koja uključuje direktnu setvu. Prihranjivanje sa količinom od 60 kg/ha uticalo je na povećanje prinosa prosečno za 20,44%, a sa 120 kg/ha za 24.73%, u odnosu na kontrolu bez prihranjivanja

Delivery of a Chlamydial Adhesin N-PmpC Subunit Vaccine to the Ocular Mucosa Using Particulate Carriers

Trachoma, caused by the intracellular bacterium Chlamydia trachomatis (Ct), remains the world's leading preventable infectious cause of blindness. Recent attempts to develop effective vaccines rely on modified chlamydial antigen delivery platforms. As the mechanisms engaged in the pathology of the disease are not fully understood, designing a subunit vaccine specific to chlamydial antigens could improve safety for human use. We propose the delivery of chlamydia-specific antigens to the ocular mucosa using particulate carriers, bacterial ghosts (BGs). We therefore characterized humoral and cellular immune responses after conjunctival and subcutaneous immunization with a N-terminal portion (amino acid 1-893) of the chlamydial polymorphic membrane protein C (PmpC) of Ct serovar B, expressed in probiotic Escherichia coli Nissle 1917 bacterial ghosts (EcN BGs) in BALB/cmice. Three immunizations were performed at two-week intervals, and the immune responses were evaluated two weeks after the final immunization in mice. In a guinea pig model of ocular infection animals were immunized in the same manner as the mice, and protection against challenge was assessed two weeks after the last immunization. N-PmpC was successfully expressed within BGs and delivery to the ocularmucosa was well tolerated without signs of inflammation. N-PmpC- specific mucosal IgA levels in tears yielded significantly increased levels in the group immunized via the conjunctiva compared with the subcutaneously immunized mice. Immunization with N-PmpC EcN BGs via both immunization routes prompted the establishment of an N-PmpC-specific IFN gamma immune response. Immunization via the conjunctiva resulted in a decrease in intensity of the transitional inflammatory reaction in conjunctiva of challenged guinea pigs compared with subcutaneously and non-immunized animals. The delivery of the chlamydial subunit vaccine to the ocular mucosa using a particulate carrier, such as BGs, induced both humoral and cellular immune responses. Further investigations are needed to improve the immunization scheme and dosage

Levels of N-PmpC-specific IgG in the sera of BALB/c mice immunized via the conjunctiva or subcutaneously.

<p>Serum samples were collected two weeks after the completion of the immunizations and were assayed by ELISA (dilution 1:100). Each dot represents one sample. Lines indicate the mean values [A_492/620 ± SD (n = 10)] calculated for each group. The statistical significance of the observed differences was evaluated using 1-way repeated ANOVA (<i>p <0</i>.<i>05*</i>, <i>p <0</i>.<i>005</i>**, <i>p <0</i>.<i>0001</i>***). In all cases when the non-immunized group was not a reference, compared groups are indicated by arrows.</p

Levels of anti-N-PmpC mucosal IgA in tear washes from BALB/c mice obtained by two routes of immunization.

<p>Samples were collected two weeks after the completion of the immunization schedule and were assayed by ELISA (dilution 1:10). Each dot represents one sample. Lines indicate the mean values [A_492/620 ± SD (n = 10)] calculated for each group. The statistical significance of the observed differences was evaluated using 1-way repeated ANOVA using non-immunized group as a reference (<i>p <0</i>.<i>05*</i>, <i>p <0</i>.<i>005</i>**, <i>p <0</i>.<i>0001***</i>).</p

The proliferation indices (PI) of N-PmpC-stimulated splenocytes from BALB/c mice immunized according to the assigned immunization protocol.

<p>The numbers of viable splenocytes were assessed by <i>Cell</i> Counting Kit-<i>8</i> assay following a 48 h cultivation in 10% FCS/50 μM β-mercaptoethanol/RPMI 1640 medium supplemented or not with N-PmpC (10 μg/ml). Each dot represents PIs calculated for individual mouse. Lines indicate the mean values [A_492/620 ± SD (n = 10)] calculated for each group. The statistical significance of the observed differences in PIs between groups treated according to the assigned protocols was evaluated using 1-way repeated ANOVA. <i>(p < 0</i>.<i>05*</i>, <i>p < 0</i>.<i>005**</i>, <i>p <0</i>.<i>0001***)</i>. Non-immunized group was used as a reference unless otherwise indicated by two head-arrow.</p

Ocular conjunctiva of N-PmpC EcN BGs-treated and control guinea pig eyes.

<p>Guinea pigs were exposed to N-PmpC EcN BGs two and 24 h. Conjunctival epithelia from both N-PmpC EcN BGs-treated and control displayed normal cell layers and morphology. No sign of tissue edema were observed in the conjunctiva studied after exposure to N-PmpC EcN BGs compared with controls. Scale bar: 10 μm. Magnification 40x.</p

Guinea pigs were immunized with N-PmpC EcN BGs and plain EcN BGs via the conjunctiva and subcutaneously, on days 0, 14 and 28 (50 μg BGs per dose) and two weeks after the completion of the specified immunization protocol were challenged by the ocular administration of 1 x 10⁶ IFU/animal.

<p>The animals were visually assessed and scored on a daily basis. Results are presented as mean pathology score ± SD at defined time point for all animals within a group (n = 5 per group).</p