Sanitary security of foodstuffs
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Sanitary quality of maize (corn) & Mycotoxins

Research Programmes

Approval of artificial contamination methods

Artificial contamination has played an important part in the improvement of selection patterns. It enables the disease to be maintained over the years at suitable levels for effective sorting of genetic material.

In this case, the programme enabled artificial contamination methods to be approved in order to improve selection patterns for genetic material in the area of sensitivity to Fusaria.

Preparing the inoculum

 

Inoculations

 

Two methods of inoculation, specific to both sections of Fusarium, were developed:

F. Liseola

Inoculation of F. LiseolaThe period of infestation with F. Liseola began around 14 days after the appearance of lint, lasting until harvest. The highest contamination by this pathogen was observed when the ear had suffered prior damage.

The ears were damaged using a 3-pronged fork (with 1 cm long prongs) which had been soaked in demineralised water then the powder contaminated with F. Liseola. This physical damage is similar to damage caused by insects.

Inoculation was carried out 14 days after the appearance of lint for the Liseola section.

 

Fusarium graminearum

Inoculation of F. graminearumThe infestation period for F. graminearum occurs briefly around 4 - 5 days after flowering (when the lints are swollen). The greatest contamination by this pathogen is observed when the pathogen penetrates via the lints.

The powder contaminated with F. graminearum was used to contaminate the lints: a pinch was placed on the swollen lints, 4 - 5 days after they appeared.

 

© Maïsadour Semences 2020 | Doc. designed August 10, 2006 - updated 15 mars, 2007 | Mentions légales |

 

Stages for sorting genetic material

Artificial infestation was used at different stages of the selection pattern:

1) On the original populations and the first selection generations: the most sensitive elements were eliminated very early on. The tolerance of the original genetic material was thus generally improved.

2) On lines being registered: tests using artificial inoculation were repeated over a period of at least 2 years in order to obtain reliable results. The level of tolerance of the lines was taken into account when determining the choice of hybrids to be tested. Highly sensitive lines were discarded.