Conventional Maize Varieties Research Articles

Maize metabolomics in relation to cropping system and growing year

Maize is important to global food security, being one of the predominant cereals in human and domesticated livestock diets worldwide. Due to the increasing human population, it will be important to not only design cropping systems to increase maize yield and sustainability but also to improve the nutritional quality of maize edible tissues. To determine cropping system impacts on maize grain nutritional content, we sampled grain from conventional and organic maize varieties grown for three growing seasons using five cropping systems. We analyzed the grain using metabolic fingerprinting of methanol extracts with ultra-high performance liquid chromatography (UHPLC) coupled with mass spectrometry (MS), adopting both non-targeted and targeted approaches. The cropping systems are part of a long-term study at the Beltsville Agricultural Research Center in Beltsville, Maryland, and were a three-year conventional no-till rotation (NT), a three-year conventional chisel-till rotation (CT), a two-year organic rotation (Org2), a three-year organic rotation (Org3), and a six-year organic rotation (Org6). Each cropping system had been in place for at least 10 years, allowing specific cropping-system-induced alterations of soil edaphic and microbial properties. Non-targeted metabolic fingerprinting detected a total of 90 compounds, the majority of which were phenolics. Metabolic profiling was further targeted toward 15 phenolics, 1 phytohormone, 7 carbohydrates and 7 organic acids, which were quantified in the maize grain originating from the five cropping systems. Statistical analysis of this subset of quantitative data determined that cropping system can significantly influence levels of certain maize grain metabolites. However, natural impacts (growing year) were substantially greater than cropping system impacts, likely masking or over-riding some cropping system impacts. Additionally, maize cultivar genetics had greater impact than cropping system on the maize grain metabolome and was the greatest “managed” impact on the metabolite profiles. Results indicate that until natural environmental impacts on maize grain metabolite levels are understood and managed, the best approach to reliably increase maize grain nutritional quality is through development of maize cultivars with enhanced nutritional content that are robust to natural environmental influence.

The distribution of phosphorus, carotenoids and tocochromanols in grains of four Chinese maize (Zea mays L.) varieties

Grains of three specialty maize varieties and one conventional maize variety cultivated in China were collected and dissected to obtain the germ, endosperm, and pericarp fraction, and the distribution pattern of phosphorus, carotenoids, and tocochromanols was determined. The results showed that phytochemical contents varied significantly among different maize fractions. The germ fraction accounted for 78.3 to 86.5% of the total phosphorus present in the maize kernels. Over 86.9% of carotenoids were located in the endosperm. Except for waxy maize, 64.5 to 74.8% of the tocochromanols were contributed by the germ. Considerable differences in phytochemical contents were observed between the genotypes. Waxy maize contained the highest content of tocopherols, tocotrienols and tocochromanols meanwhile waxy maize had the lowest carotenoid and phytate phosphorus content. High lysine maize contained the highest levels in carotenoids and lowest tocochromanols. Over all, total carotenoids were significantly inversely associated with total tocochromanols.

Food/Feed and Environmental Risk Assessment of Herbicide-tolerant and Insect-resistant Genetically Modified Maize NK603 x MON810 for Import, Processing, Food and Feed Uses under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2004/01)

Food/Feed and Environmental Risk Assessment of Herbicide-tolerant and Insect-resistant Genetically Modified Maize NK603 x MON810 for Import, Processing, Food and Feed Uses under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2004/01)

Diazotrophic bacteria from maize exhibit multifaceted plant growth promotion traits in multiple hosts.

Sierra Mixe maize is a geographically remote landrace variety grown on nitrogen-deficient fields in Oaxaca, Mexico that meets its nutritional requirements without synthetic fertilizer by associating with free-living diazotrophs comprising the microbiota of its aerial root mucilage. We selected nearly 500 diazotrophic (N2-fixing) bacteria isolated from Sierra Mixe maize mucilage and sequenced their genomes. Comparative genomic analysis demonstrated that isolates represented diverse genera and composed three major diazotrophic groups based on nitrogen fixation gene content. In addition to nitrogen fixation, we examined deamination of 1-amino-1-cyclopropanecarboxylic acid, biosynthesis of indole-3-acetic acid, and phosphate solubilization as alternative mechanisms of direct plant growth promotion (PGP). Genome mining showed that isolates of all diazotrophic groups possessed marker genes for multiple mechanisms of direct plant growth promotion (PGP). Implementing in vitro assays corroborated isolate genotypes by measuring each isolate’s potential to confer the targeted PGP traits and revealed phenotypic variation among isolates based on diazotrophic group assignment. Investigating the ability of mucilage diazotrophs to confer PGP by direct inoculation of clonally propagated potato plants in planta led to the identification of 16 bio-stimulant candidates. Conducting nitrogen-stress greenhouse experiments demonstrated that potato inoculation with a synthetic community of bio-stimulant candidates, as well as with its individual components, resulted in PGP phenotypes. We further demonstrated that one diazotrophic isolate conferred PGP to a conventional maize variety under nitrogen-stress in the greenhouse. These results indicate that, while many diazotrophic isolates from Sierra Mixe maize possessed genotypes and in vitro phenotypes for targeted PGP traits, a subset of these organisms promoted the growth of potato and conventional maize, potentially through the use of multiple promotion mechanisms.

Food/Feed and Environmental Risk Assessment of Insect Resistant Genetically Modified Maize 1507 for Cultivation, Import, Processing, Food and Feed Uses under Directive 2001/18/EC and Regulation (EC) No 1829/2003 (C/ES/01/01, C/NL/00/10, EFSA/GMO/NL/2004/02)

Food/Feed and Environmental Risk Assessment of Insect Resistant Genetically Modified Maize 1507 for Cultivation, Import, Processing, Food and Feed Uses under Directive 2001/18/EC and Regulation (EC) No 1829/2003 (C/ES/01/01, C/NL/00/10, EFSA/GMO/NL/2004/02)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize GA21 from Syngenta Seeds for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/19)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize GA21 from Syngenta Seeds for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/19)

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 x GA21 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/49)

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 x GA21 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/49)

Food/Feed and Environmental Risk Assessment of Insect-resistant Genetically Modified Maize MIR604 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/11)

Food/Feed and Environmental Risk Assessment of Insect-resistant Genetically Modified Maize MIR604 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/11)

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 from Syngenta Seeds for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/RX/Bt11)

Food/Feed and Environmental Risk Assessment of Insect-Resistant and Herbicide-Tolerant Genetically Modified Maize Bt11 from Syngenta Seeds for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/RX/Bt11)

Food/Feed and Environmental Risk Assessment of Application (Reference EFSA/GMO/UK/2008/56) for Authorization of Insect Resistant and Herbicide Tolerant Genetically Modified Maize Bt11 x MIR604 x GA21 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 from Syngenta Seeds

Food/Feed and Environmental Risk Assessment of Application (Reference EFSA/GMO/UK/2008/56) for Authorization of Insect Resistant and Herbicide Tolerant Genetically Modified Maize Bt11 x MIR604 x GA21 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 from Syngenta Seeds

Food/feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize MIR604 x GA21 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/48)

Food/feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize MIR604 x GA21 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/48)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize Bt11 x MIR604 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/50)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize Bt11 x MIR604 in the European Union under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2007/50)

Food/Feed and Environmental Risk Assessment of Insect Resistant Genetically Modified Maize MON810 for Cultivation, Seed Production, Import, Processing and Feed Uses under Directive 2001/18/EC (Notification C/F/95/12/02)

Food/Feed and Environmental Risk Assessment of Insect Resistant Genetically Modified Maize MON810 for Cultivation, Seed Production, Import, Processing and Feed Uses under Directive 2001/18/EC (Notification C/F/95/12/02)

Food and Environmental Risk Assessment of Herbicide-tolerant Genetically Modified Maize NK603 for Food Uses, Import and Processing under Directive 2001/18/EC (Notification C/ES/00/01)

Food and Environmental Risk Assessment of Herbicide-tolerant Genetically Modified Maize NK603 for Food Uses, Import and Processing under Directive 2001/18/EC (Notification C/ES/00/01)

Food/feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 59122 x NK603 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/20)

Food/feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 59122 x NK603 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/20)

Final Health and Environmental Risk Assessment of Genetically Modified Maize 59122

Final Health and Environmental Risk Assessment of Genetically Modified Maize 59122

Final Health and Environmental Risk Assessment of Genetically Modified Maize MON 89034

Final Health and Environmental Risk Assessment of Genetically Modified Maize MON 89034

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 59122 x 1507 x NK603 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/21)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 59122 x 1507 x NK603 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/UK/2005/21)

Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 1507 x 59122 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/NL/2005/15)

Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 1507 x 59122 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/NL/2005/15)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 1507 x 59122 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/NL/2005/15)

Food/Feed and Environmental Risk Assessment of Insect-resistant and Herbicide-tolerant Genetically Modified Maize 1507 x 59122 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (EFSA/GMO/NL/2005/15)