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Will
transformation systems for the large seeded grain legumes, peas, lupins
or chickpeas be adaptable to cowpea?
T.J.V. Higgins,
L Molvig, W. Tate, S. Gollasch & L.M. Tabe
It
is now possible to transform many large-seeded grain legumes. Although
the rate of recovery of transgenic lines together with transmission to
the next generation is low, the systems are robust enough to allow
transfer of the technology from lab to lab. Low efficiency, means that
0.3 to 1% of the starting explants will result in a unique
transformation event. Thus,
it is still a very laborious process and it is clear that a large-scale
effort is needed for any pulse legume project.
We find that it is important to avoid a callus phase during
regeneration and transformation. Other
features that are critical to success are selection of an explant that
regenerates in tissue culture with a high frequency.
The choice of selection agent, medium type and hormonal regime,
while important, are of secondary significance.
Three approaches to transformation of legumes can be illustrated
with peas and chickpeas expressing a bean a-amylase
inhibitor gene and lupins expressing a gene for a rumen-stable, high
sulfur, amino acid-containing protein.
The aims of this research are to improve field performance and
seed quality of peas and chickpeas.
Enhanced seed protein quality of lupins is aimed at more
efficient ruminant animal production.
These approaches to pulse transformation are being adapted to
cowpea.
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