Impact of genetic structures on haploid genome-based quantification of genetically modified DNA: theoretical considerations, experimental data in MON 810 maize kernels (Zea mays L.) and some practical applications

The pattern of aleurone variegation of maize kernels carrying Ac and bz-m2(DI) as reporter allele for Ac activity depends on the dosage of both Ac and Ds. Alterations of Ac dosage can abolish Ds excision at certain times and allow it to occur at other times. wx-m7 and wx-m9 are different Ac insertions in the Waxy gene which have different dosage effects on Ds excision. Kernels, heterozygous for the two Ac alleles and being either wx-m7/wx-m7/wx-m9 or wx-m9/wx-m9/wx-m7 exhibit characteristic patterns of predominantly late excisions; this is in strong contrast to the pattern of early excisions present on wx-m7/wx-m7/wx-m7 homozygotes. This observation supports the hypothesis that the Ac alleles express different amounts of transposase (TPase) during development and that above a certain level of TPase transposition is inhibited. Furthermore, experimental results suggest that the frequency of Ac-induced events is influenced by the dosage and composition of the transactivated Ds or Ac allele. Thus, transposition frequency seems not to be exclusively determined in trans by the amount of active TPase, but also by specific cis-acting properties of the TPase substrate.

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Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed

Toxicology and Industrial Health ◽

10.1177/0748233713505125 ◽

2013 ◽

Vol 32 (4) ◽

pp. 614-624 ◽

Cited By ~ 1

Author(s):

Muhammad Ibrahim ◽

Naseer Ahmed ◽

Faizan Ullah ◽

Zabta Khan Shinwari ◽

Asghari Bano

Keyword(s):

Zea Mays ◽

Zea Mays L ◽

Genetically Modified

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Maize (Zea Mays L) landraces from the southern region of Brazil: contamination by Fusarium sp, zearalenone, physical and mechanical characteristics of the kernels

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132009000700002 ◽

2009 ◽

Vol 52 (spe) ◽

pp. 11-16 ◽

Cited By ~ 6

Author(s):

Tatiana Roselena de Oliveira ◽

David de Souza Jaccoud-Filho ◽

Luciana Henneberg ◽

Milton Domingos Michel ◽

Ivo Mottin Demiate ◽

...

Keyword(s):

Zea Mays ◽

Mechanical Characteristics ◽

Zea Mays L ◽

Southern Region ◽

Fusarium Sp ◽

Maize Kernels ◽

Physical And Mechanical Characteristics

This work had as objectives the study of the physical and mechanical characteristics of maize kernels in relation to the contamination by Fusarium sp and by zearalenone in twenty landraces of maize from the southern region of Brazil. From the analyzed samples, 60 % has been considered to have a hard endosperm type and 40 % an intermediary one. A correlation between the physical and mechanical variables was observed as an indication that the higher is the proportion of hard endosperm, more dense will be the kernel and more force for its rupture will be necessary. The level of contamination by Fusarium sp was between 5.5 and 24.75% among the analyzed grains, correlating positively with the flotation index, indicating that the landraces of maize with a softer endosperm can present a higher contamination by this genus. The presence of zearalenone was verified in 75 % of the samples, in concentrations varying from 50 to 640 µg kg-1.

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Some factors influencing electrolyte leakage from maize (Zea mays L.) kernels

Seed Science Research ◽

10.1017/s0960258500000581 ◽

1991 ◽

Vol 1 (1) ◽

pp. 15-20 ◽

Cited By ~ 19

Author(s):

H. Bruggink ◽

H. L. Kraak ◽

M. H. G. E. Dijkema ◽

J. Bekendam

Keyword(s):

Zea Mays ◽

Moisture Content ◽

Electrolyte Leakage ◽

Zea Mays L ◽

Mechanical Damage ◽

Kernel Weight ◽

Conductivity Measurements ◽

Factors Influencing ◽

Quality Testing ◽

Maize Kernels

AbstractEven though the embryo of a maize (Zea mays L.) kernel contributes relatively little to total kernel weight, it is a main source of electrolytes which leach from the kernel during imbibition. Ageing of maize kernels for 18 days at 40°C and a moisture content of about 15% results in an increase of electrolyte leakage which almost exclusively originates from the embryo. The effect of ageing is most apparent after prolonged periods of imbibition. Mechanical damage increases leakage early during imbibition, the effect of damage being considerably larger for aged than for unaged kernels. The large amount of electrolytes measured after the first hour of imbibition of undamaged kernels comes mainly from the pericarp. The electrolyte content of the pericarp is variety dependent and may interfere with quality testing by conductivity measurements.

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