Search results for "Zea may"

Loss of virulence in Ustilago maydis by Umchs6 gene disruption

2003

A gene encoding a sixth chitin synthase (Umchs6, sequence GenBank accession No. AF030554) from the plant pathogenic hemibasidiomycete Ustilago maydis (DC.) Cda. was isolated and characterized. The predicted protein is 1103 amino acids in length with a calculated molecular mass of 123.5 kDa. a2b2 null mutants were obtained by substitution of a central fragment of the Umchs6 gene with the hygromycin resistance cassette, and a1b1 null mutants were obtained by genetic recombination in plants of an a2b2Δch6 and a wild-type a1b1 strain. The mutation had no effect on the dimorphic transition in vitro or on mating, and growth rate of the mutants was only slightly reduced. On the other hand, they di…

Pyrosequencing vs. culture-dependent approaches to analyze lactic acid bacteria associated to chicha, a traditional maize-based fermented beverage fr…

2015

The diversity of lactic acid bacteria (LAB) associated with chicha, a traditional maize-based fermented alcoholicbeverage from Northwestern Argentina, was analyzed using culture-dependent and culture-independent approaches.Samples corresponding to 10 production steps were obtained from two local producers at Maimará(chicha M) and Tumbaya (chicha T). Whereas by culture-dependent approach a few number of species(Lactobacillus plantarum and Weissella viridescens in chicha M, and Enterococcus faecium and Leuconostocmesenteroides in chicha T) were identified, a higher quantitative distribution of taxa was found in both beveragesby pyrosequencing. The relative abundance of OTUs was higher in chic…

Cropping system dynamics, climate variability, and seed losses among East African smallholder farmers: a retrospective survey.

2014

Abstract Climate variability directly affects traditional low input and rain-fed farming systems, but few studies have paid attention retrospectively to the cropping system’s ability to mitigate climate risk. This study analyzes the impacts of rainfall variability on farmers’ seed variety losses over time, considering changes in smallholder farming systems. The cropping system dynamics, in favoring maize at the expense of sorghum and pearl millet, have induced an increasing risk of seed loss during drought. Combining ecological anthropology and climatology, a retrospective survey asking farmers about the period 1961–2006 was carried out at three altitudinal levels (750, 950, and 1100 m) on …

The Largest Subunit of RNA Polymerase II as a New Marker Gene to Study Assemblages of Arbuscular Mycorrhizal Fungi in the Field

2014

Due to the potential of arbuscular mycorrhizal fungi (AMF, Glomeromycota) to improve plant growth and soil quality, the influence of agricultural practice on their diversity continues to be an important research question. Up to now studies of community diversity in AMF have exclusively been based on nuclear ribosomal gene regions, which in AMF show high intra-organism polymorphism, seriously complicating interpretation of these data. We designed specific PCR primers for 454 sequencing of a region of the largest subunit of RNA polymerase II gene, and established a new reference dataset comprising all major AMF lineages. This gene is known to be monomorphic within fungal isolates but shows an…

Biostimulant Potential of Humic Acids Extracted From an Amendment Obtained via Combination of Olive Mill Wastewaters (OMW) and a Pre-treated Organic …

2018

Olive mill wastewaters (OMW) detain contain significant levels of phenolic compounds with antimicrobial/phytotoxic activity and high amounts of undecomposed organic matter that may a high pollutant load that exerts negative effects on soil biology because of significant levels in phenolic compounds with antimicrobial/phytotoxic activity and limited biodegradability, and high amounts of undecomposed organic matter. Among OMW detoxification techniques, those focusing on oxidative degradation of phenolic compounds are relevant those focusing on oxidative degradation of phenolic compounds to reduce their toxicity. The composting (bio-oxidation) process in particular, exploits exothermic oxidati…

Effects of Environmental Lighting and Tryptophan Devoid Diet on the Rat Vaginal Cycle

1998

Cerebral serotonin level influences luteinizing hormone release and, consequently, ovulation. The present study evaluated the effects of precooked maize meal (polenta), a diet almost devoid of tryptophan the serotonin precursor on the alterations of the estrus cycle as measured by vaginal smears analysis in Wistar rats. Several conditions of environmental lighting were used in order to modify ovarian cycle: 1) natural alternating light/dark cycle; 2) continuous darkness; 3) continuous light by sodium steams: 4) continuous light by fluorescent neon tubes. Rats bred in continuous lighting showed estrus-proestrus rate significantly greater than rats bred in normal lighting or in continuous dar…

Scientific Opinion on an application by Syngenta (EFSA-GMO-DE-2009-66) for placing on the market of herbicide tolerant and insect resistant maize Bt1…

2015

Question number: EFSA-Q-2009-00444 on request from Competent Authority of Germany; The EFSA GMO Panel previously assessed the four single events combined to produce a four-event stack maize Bt11 × MIR162 × MIR604 × GA21 and did not identify safety concerns. In this opinion, the EFSA GMO Panel assesses the four-event stack maize and all its subcombinations independently of their origin. No new data on the single events, leading to modification of the original conclusions on their safety, were identified. The molecular, agronomic, phenotypic and compositional data on the four-event stack maize did not give rise to safety concerns and there is no reason to expect interactions between the singl…

Smagā metāla svina uzkrāšanās kukurūzas augos un ietekme uz fizioloģiskajiem parametriem saistībā ar vermikomposta saturu substrātā

2017

Svina pieaugošā piesārņojuma un tā lielās toksicitātes dzīvajos organismos dēļ ir ļoti svarīgi meklēt efektīvus un praktiski pielietojamus līdzekļus, kas ļautu samazināt tā piesārņojumu. Pēdējā laikā tiek vērsta uzmanība uz dabiskas izcelsmes materiāliem kā iespējamiem svina saistītājiem. Viens no tādiem ir vermikomposts, kura sastāvā lielā daudzumā esošo humīnvielu spēja saistīt smagos metālus, tiek skaidrota ar vermikomposta iespējamo pozitīvo efektu. Darba mērķis ir noskaidrot, kāda ir svina ietekme uz kukurūzas (Zea mays) augšanas un fizioloģiskajiem parametriem un kā tie izmainās, pievienojot substrātam vermikompostu, kā arī noteikt, vai pievienotais vermikomposts samazina svina uzkrāš…

Production of feeds for African catfish Clarias gariepinus using plant proteins

2012

Anatomiskās, morfoloģiskās un fizioloģiskās izmaiņas kukurūzai (Zea mays L.) un lauka pupām (Vicia faba) cinka ietekmē

2017

Piesārņojums ar smagajiem metāliem ir aktuāla pasaules mēroga problēma, kas galvenokārt saistīta ar metalurģijas un intensīvās lauksaimniecības attīstību un tās radītajām sekām. Pētījumu veica Latvijas Universitātes Bioloģijas fakultātes Augu Fizioloģijas katedrā laika posmā no 2015. gada oktobra līdz 2017. gada maijam. Šī darba mērķis bija izpētīt dažādu cinka koncentrāciju substrātā ietekmi uz augu morfoloģiskajām, anatomiskajām un fizioloģiskajām izmaiņām, kā modeļobjektus izmantojot lauka pupu (Vicia faba) un kukurūzu (Zea mays). Pētījumā atklājās, ka lauka pupās un kukurūzā hlorofila koncentrācija lapās variantos ar mazu cinka koncentrāciju palielinās, bet variantos ar lielu cinka konc…