POD SHATTER IN RAPE

Résultats exploitables

Pod shatter denotes the opening of oilseed rape silques and dispersal of the seeds as they mature. Flowering and seed shatter is not synchronous in rape; hence there is no such thing as the 'correct harvest time'. Immature seeds contain more moisture and more chlorophyll both of which lead to reduced oil quality. Late harvest dates leading to less immature seeds is often accompanied by loss of yield and problems with fighting run-away rape with chemical herbicides in the following year. Swathing reduces the risk that wind bring about excessive shattering of seeds from the most mature pods while allowing the younger ones to catch up to some extent. Timing of swathing is very critical and it is not always that yields are greater than the potential yield from a crop harvested by direct combining. Technology is being developed to engineering shatter resistance into oilseed rape using the tools of molecular biology Two physiologically distinct approaches towards obtaining a selective delay of pod opening relative to seed maturation are being investigated: interference with the enzymes that bring about the physical separation of the carpels; interference with the hormonal regulation of the pod opening process in broader terms. An examination was made of the roles of endo-polygalacturonase in dissolution of load bearing structures holding the carpels together and a detailed examination was carried out of the roles of auxins and ethylene and its precursor on the initiation or stimulation of pod opening. Such studies have enabled the possibility of breeding greater shatter resistance in transgenic plants, based on key elements of the pod opening process, based on interference with pod opening. So far a solid foundation for two main approached aimed at engineering shatter resistance has been established. A rape transformation procedure is in place, and the first generation of are being developed.

Résultats exploitables

Partager cette page

Télécharger