Alternativas de controle químico de junquinho resistente aos herbicidas inibidores da als.

Cyperus iria L. (CYPIR) é uma das principais ciperáceas ocorrentes em lavouras de arroz irrigado. Durante muitos anos, os herbicidas inibidores da enzima acetolactato sintase (ALS) foram a principal ferramenta para controle de CYPIR, favorecendo a seleção de biótipos com resistência cruzada. Com base no nível de resistência, é necessária a adoção de medidas de controle químico alternativo a fim de evitar a evolução da resistência e reduzir a interferência sobre a cultura. O objetivo desse trabalho foi avaliar alternativas de controle químico de CYPIR com resistência cruzada aos herbicidas inibidores da ALS, ocorrente em lavouras de arroz irrigado no Sul do Brasil. Dois experimentos foram conduzidos em casa de vegetação, em delineamento inteiramente casualizado com quatro repetições. Os herbicidas utilizados foram: imazethapyr; formulação de imazapyr+imazapic; bentazon; propanil; formulação de bentazon+imazamox; mistura de (bentazone + imazamox) + (imazapyr + imazapic); associação de bentazone + formulação de (imazapyr + imazapic); glyphosate; e testemunha sem herbicida. A avaliação do controle foi realizada em biótipo resistente (CYPIR-R) e suscetível (CYPIR-S), e a fitotoxicidade avaliada nas cultivares Guri Inta CL, IRGA 424 RI e IRGA 409. Aos 28 dias após aplicação (DAA) foi avaliado o controle/ fitotoxicidade e a matéria seca da parte aérea (MSPA). Todos os tratamentos testados, com exceção do imazethapyr e formulação de imazapyr+imazapic isolados, foram eficientes. Há alternativas para o controle químico de Cyperus iria resistente aos inibidores da ALS e esses, quando associados com produtos que apresentam mecanismo de ação diferentes, não inviabilizam o uso da tecnologia ClearField®.Cyperus iria L. (CYPIR) is one of the main cyperaceae occurring in irrigated rice crop. For many years, acetolactate synthase inhibitor herbicides (ALS) were the main tool to control CYPIR, favoring the selection of cross-resistance biotypes. Based on the level of resistance, it is necessary to adopt alternative chemical control measures in order to avoid the evolution of the resistance and to reduce the interference on the crop. The aim of this work was to evaluate alternatives of chemical control of CYPIR to ALS-inhibiting herbicides, occurring in irrigated rice crops in southern Brazil. There were conducted two experiments in greenhouse, arranged in completely randomized design with four replicates. The herbicides used were: imazethapyr; imazapyr+imazapic formulation; bentazon; propanil; formulation of bentazon+imazamox; mixture of (bentazone + imazamox) + (imazapyr + imazapic); association of bentazone + (imazapyr + imazapic); glyphosate; and control without herbicide. The control evaluation was performed in a resistant (CYPIR-S) and susceptible (CYPIR-S) biotype, and the phytotoxicity evaluated in the Guri Inta CL, IRGA 424 RI and IRGA 409 cultivars. At 28 days after application (DAA) the control / phytotoxicity and shoot dry matter (SDM) were evaluated. All treatments tested, except for imazethapyr and imazapyr+imazapic applied in isolation, were efficient. There are alternatives to the chemical control of Cyperus iria resistant to ALS-inhibiting herbicides and these, when associated with products that have different mechanisms of action, do not impair the use of ClearField® technology

Effects of Simulated Microgravity on Embryonic Stem Cells

There have been many studies on the biological effects of simulated microgravity (SMG) on differentiated cells or adult stem cells. However, there has been no systematic study on the effects of SMG on embryonic stem (ES) cells. In this study, we investigated various effects (including cell proliferation, cell cycle distribution, cell differentiation, cell adhesion, apoptosis, genomic integrity and DNA damage repair) of SMG on mouse embryonic stem (mES) cells. Mouse ES cells cultured under SMG condition had a significantly reduced total cell number compared with cells cultured under 1 g gravity (1G) condition. However, there was no significant difference in cell cycle distribution between SMG and 1G culture conditions, indicating that cell proliferation was not impaired significantly by SMG and was not a major factor contributing to the total cell number reduction. In contrast, a lower adhesion rate cultured under SMG condition contributed to the lower cell number in SMG. Our results also revealed that SMG alone could not induce DNA damage in mES cells while it could affect the repair of radiation-induced DNA lesions of mES cells. Taken together, mES cells were sensitive to SMG and the major alterations in cellular events were cell number expansion, adhesion rate decrease, increased apoptosis and delayed DNA repair progression, which are distinct from the responses of other types of cells to SMG

Diagnóstico preliminar de perdas de grãos na colheita de soja em Campo Novo do Parecis (MT) na safra 2015/2016.

(Embrapa Soja. Documentos, 372)

Two Estrogen Response Element Sequences Near the PCNA Gene Are Not Responsible for Its Estrogen-Enhanced Expression in MCF7 Cells

The proliferating cell nuclear antigen (PCNA) is an essential component of DNA replication, cell cycle regulation, and epigenetic inheritance. High expression of PCNA is associated with poor prognosis in patients with breast cancer. The 5'-region of the PCNA gene contains two computationally-detected estrogen response element (ERE) sequences, one of which is evolutionarily conserved. Both of these sequences are of undocumented cis-regulatory function. We recently demonstrated that estradiol (E2) enhances PCNA mRNA expression in MCF7 breast cancer cells. MCF7 cells proliferate in response to E2.Here, we demonstrate that E2 rapidly enhanced PCNA mRNA and protein expression in a process that requires ERalpha as well as de novo protein synthesis. One of the two upstream ERE sequences was specifically bound by ERalpha-containing protein complexes, in vitro, in gel shift analysis. Yet, each ERE sequence, when cloned as a single copy, or when engineered as two tandem copies of the ERE-containing sequence, was not capable of activating a luciferase reporter construct in response to E2. In MCF7 cells, neither ERE-containing genomic region demonstrated E2-dependent recruitment of ERalpha by sensitive ChIP-PCR assays.We conclude that E2 enhances PCNA gene expression by an indirect process and that computational detection of EREs, even when evolutionarily conserved and when near E2-responsive genes, requires biochemical validation

PCNA levels in neuroblastoma are increased in tumors with an amplified N- myc gene and in metastatic stage tumors

N- myc oncogene amplification in neuroblastoma has been found to be significantly associated with advanced stage disease and tumor progression. However, there is a lack of data on tumors, regarding the relationship between N- myc gene amplification and proliferation activity. Proliferating cell nuclear antigen (PCNA) is a proliferation-induced 36 kD nuclear protein that is the auxiliary component of DNA polymerase δ. PCNA levels in tissues have been found to correlate with proliferative activity. We have examined PCNA levels in neuroblastomas in relation to N- myc gene amplification and tumor stage. Statistically, significantly higher levels of PCNA were observed in tumors with an amplified N- myc gene relative to tumors with a single gene copy. The highest levels of PCNA were observed in advanced stage tumors with an amplified N- myc gene. Treatment of neuroblastoma cells in culture with retinoic acid, which induces differentiation, resulted in a substantial decrease in PCNA. Our results suggest that PCNA levels may reflect differences in proliferative activity between neuroblastomas, related to stage of the disease and to N- myc gene copy number.[/p ]Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42581/1/10585_2004_Article_BF00880069.pd

Effect of companion crops of catch crop on the productivity of crop-rotation link: spring barley – winter wheat

W pracy przedstawiono wyniki badań przeprowadzonych w latach 1998- 2001 w Stacji Badawczej w Mochełku na glebie kompleksu żytniego dobrego, w ogniwie zmianowania jęczmień jary – pszenica ozima. Badano wpływ uprawy wsiewek międzyplonu na plonowanie jęczmienia jarego (rośliny ochronnej) i pszenicy ozimej (rośliny następczej) oraz na produkcyjność ogniwa zboże jare – zboże ozime. Określono także plony zielonej masy wsiewek i ich oddziaływanie na zboża w zależności od ilości i rozkładu opadów. Plonowanie wsiewek, zwłaszcza roślin bobowatych, było silnie zróżnicowane w latach badań. Stwierdzono, że największy plon zielonej masy zarówno w momencie zbioru jęczmienia jarego, jak i w odroście pożniwnym wydawały na ogół cykoria oraz życica wielokwiatowa. Wsiewki koniczyny białej i seradeli, mimo mniejszych plonów, zwiększyły o 1,5-4,1%, a wsiewki cykorii i życicy wielokwiatowej zmniejszyły o 5,3- 8,7% produkcyjność ogniwa jęczmień jary – pszenica ozima.The present paper covers the results of studies carried out in 1998-2001 on a good rye soil complex at the Mochełek Experiment Station which involved spring barley – winter wheat crop rotation link. There were evaluated the effects of companion crops of catch crop on the yield of spring barley (a cover crop) and winter wheat (a successive crop) as well as on the productivity of the link: spring cereal – winter cereal. Also green matter yield of companion crops was defined and their effect on cereals depending on precipitation and its distribution. Companion crops yielding, especially Fabaceae, varied greatly over the study years. It was found that the highest yield of green matter, both upon spring barley harvest and post-harvest regrowth, was noted for chicory and Italian ryegrass. Companion crops of white clover and serradella, despite lower yields, increased the productivity of spring barley – winter wheat crop rotation link by 1.5-4.1% and chicory and Italian ryegrass decreased it by 5.3-8.7%

Wpływ nawożenia organicznego i mineralnego oraz użyźniacza glebowego na zachwaszczenie plantacji ziemniaka

The number of weed species occurring in agricultural crops in Poland ranges from 300 to 400, and in potato cultivation this number ranges from 29 to 55 species. Potato is a plant which is heavily grown over with weeds, since it is cultivated in wide row spaces and is characterized by slow initial growth. The aim of the 3-year study was to estimate the effect of cultivation practices such as limited mineral fertilization, the use of farmyard and straw, catch crop cultivation, as well as the use of a soil fertilizer on the occurrence of weeds in a potato plantation. It was shown that the numbers of weeds determined in three growing seasons before row closure stayed at low level (2-9 plants per m2), and before tuber harvest it was only slightly higher. Among dicotyledonous weed species, the most frequently occurred: white goose-foot (Chenopodium album L.), field violet (Viola arvensis Murr.), smallflower galinsoga (Galinsogaparviflora Cav.) and shepherd’s purse (Capsella bursa-pastoris L Med.), and of monocotiledonous – barnyard grass (Echinochloa crus galli L.) and quack grass (Elymusrepens L.). The lowest weed infestation, particularly with dicotyledonous species, was recorded after the application of straw as organic fertilizer. Smallest number of dicotyledonous weeds occurred when the standard rate of mineral fertilizers was reduced by 50%. Whereas the use of the soil fertilizer UGmax caused increase in the numbers of monocotyledonous weeds before potato row closure and of both monocotyledonous and dicotyledonous before tuber harvest. The smallest weed infestation occurred when straw fertilization was used, mineral fertilization was reduced by 50% and the soil fertilizer was not applied.W Polsce liczba gatunków chwastów występujących w uprawach rolniczych wynosi od 300 do 400, a w uprawie ziemniaka liczba ta waha się w granicach od 29 do 55 gatunków. Ziemniak jest rośliną, która silnie się zachwaszcza, gdyż uprawiany jest w szerokiej rozstawie rzędów oraz charakteryzuje się powolnym początkowym wzrostem. Celem 3-letnich badań było określenie wpływu zabiegów agrotechnicznych, takich jak ograniczone nawożenie mineralne, stosowanie obornika i słomy, uprawa międzyplonów, a także stosowanie użyźniacza glebowego na występowanie chwastów na plantacji ziemniaka. Wykazano, że liczebność chwastów oznaczanych w trzech sezonach wegetacyjnych przed zwarciem rzędów kształtowała się na niskim poziomie (2-9 szt. na m2), a przed zbiorem bulw była tylko nieznacznie wyższa. Wśród dwuliściennych gatunków chwastów najliczniej występowały: komosa biała (Chenopodium album L.), fiołek polny(Viola arvensis Murr.), żółtlica drobnokwiatowa (Galinsoga parviflora Cav.) i tasznik pospolity(Capsella bursa-pastorisL Med.), a jednoliściennych chwastnica jednostronna (Echinochloa crus galli L.) i perz właściwy(Elymus repens L.). Najmniejsze zachwaszczenie, zwłaszcza gatunkami dwuliściennymi, zanotowano po zastosowaniu słomy jako nawozu organicznego. Mniejsza liczba chwastów dwuliściennych występowała wtedy, gdy standardową dawkę nawozów mineralnych zmniejszono o 50%. Stosowanie użyźniacza glebowego UGmax spowodowało natomiast zwiększenie liczby chwastów jednoliściennych przed zwarciem rzędów ziemniaka oraz jedno- i dwuliściennych przed zbiorem bulw. Najmniejsze zachwaszczenie występowało wówczas, gdy stosowano nawożenie słomą, zmniejszono o 50% nawożenie mineralne i nie stosowano użyźniacza glebowego

Effect of fertilisation with straw, stubble intercrops, and varied tillage on some properties of soil in the crop-rotation link: winter wheat – spring barley

Celem badań przeprowadzonych w latach 1999-2002 na glebie kompleksu żytniego dobrego było określenie wpływu nawożenia słomą, uprawy międzyplonów ścierniskowych i sposobu umieszczenia biomasy roślinnej w glebie przez zróżnicowaną uprawę roli na niektóre właściwości warstwy ornej w ogniwie zmianowania pszenica ozima – jęczmień jary. Nawożenie słomą spowodowało zmniejszenie zawartości azotu mineralnego w glebie jesienią. Pod wpływem spłycenia pożniwnej i rezygnacji z przedzimowej uprawy roli zmniejszyła się wilgotność, wzrosła zwięzłość gleby i zwiększyło się zachwaszczenie rośliny następczej. Uprawa międzyplonów ograniczała na ogół zachwaszczenie i ilość azotu mineralnego w glebie, ale zwłaszcza przy niedoborze opadów może zwiększać zwięzłość gleby i zmniejszać jej wilgotność. Możliwość uprawy żyta ozimego w międzyplonie ścierniskowym, w warunkach rezygnacji z przedzimowej uprawy roli, jest ograniczona, prowadzi bowiem wiosną do niekorzystnych zmian właściwości warstwy ornej gleby.The objective of the study carried out over 1999-2002 on good rye soil complex soil was to evaluate the effect of fertilisation with straw, cultivation of stubble intercrops and the method of placing plant biomass in soil by varied tillage on some properties of soil arable layer in the crop-rotation link: winter wheat – spring barley. The fertilisation with straw decreased the mineral nitrogen concentration in soil in autumn. As a result of a less deep post-harvest tillage and abandoning the pre-winter tillage, soil moisture decreased, while the soil compaction as well as weed infestation of the successive crop increased. The cultivation of intercrops usually limited the weed infestation and the amount of mineral nitrogen in soil, especially with a rainfall deficit, the soil compactness could increase and its moisture – decrease. The cultivation of winter rye in stubble intercrop, with no pre-winter tillage, is limited as it leads to unfavourable changes in the topsoil properties in spring

Wpływ glifosatu użytego do desykacji gorczycy białej (Sinapis alba L.) na wartość siewną nasion

In the years 2008-2010 the effect of glyphosate used before harvesting of white mustard at a dose of 1.0 and 2.0 kg a.s.·ha-1 on the value of its seeds was studied. Evaluation included: weight of one thousand seeds, uniformity, weight test, energy and germination capacity as well as the initial sprout growth. Also plant emergence from seeds planted at the depth of 2 and 4 cm was determined. The effect of glyphosate on physical parameters of seeds, as well as on germination capacity and emergence capacity depended on its dose. Applied at a dose of 2.0 kg a.s.·ha-1 it decreased uniformity and the weight of one thousand seeds, and because of the decrease of germination capacity below 87% and emergence from depth of 2 cm, it prevents their utilization as a seed material. Decrease of emergence from greater depths as a result of application of even 1.0 kg of glyphosate per ha, decreases the risk of self-sown plants as relative weeds.W latach 2008-2010 badano wpływ glifosatu stosowanego przed zbiorem gorczycy białej w dawce 1,0 i 2,0 kg s.a.·ha-1 na jakość jej nasion. Oceniono: masę tysiąca nasion, wyrównanie, gęstość w stanie zsypnym, energię i zdolność kiełkowania oraz początkowy wzrost kiełków. Określono także wschody roślin z nasion umieszczonych na głębokości 2 i 4 cm. Oddziaływanie glifosatu na parametry fizyczne nasion, a także zdolność kiełkowania i wschodów zależało od jego dawki. Stosowany w dawce 2,0 kg s.a.·ha-1 zmniejszył wyrównanie i masę tysiąca nasion, a z powodu ograniczenia zdolności kiełkowania poniżej 87% i wschodów już z głębokości 2 cm uniemożliwia ich wykorzystanie jako materiału siewnego. Ograniczenie wschodów z większych głębokości w wyniku aplikacji nawet 1,0 kg glifosatu na ha zmniejsza ryzyko występowanie samosiewów jako chwastów fakultatywnych