Development of an efficient and cost-effective doubled haploid production
system and genetic transformation system are the prerequisite to initiate
haploid breeding and genetic modification in flax respectively.
Pre-culturing anthers on a high osmotic, high auxin and high mineral salt
concentration for a period of time before transfer to a low osmotic, low
auxin and low salt concentration significantly increased the overall
efficiency of regeneration or anther efficiency than directly culturing
anthers on a low osmotic, low auxin and low salt concentration medium.
This culture procedure also dramatically reduced the frequency of shoot
regeneration from somatic cells in anther culture. Using this procedure,
a highly efficient anther culture-derived callus based transformation
system was developed. The transformation efficiency of anther
culture-derived callus based transformation system was four times higher
than the best reported transformation efficiency using hypocotyls as the
ex-plants in Agrobacterium tumefaciens based transformation system or
particle bombardment based transformation system. The frequency of escape
in anther culture-derived callus based transformation system was one
third of that in hypocotyl-based transformation system using A.
tumefaciens or one half using particle bombardment. This very high
efficient transformation system will prove to be very valuable in basic
research for gene discovery and practical applications in genetic
engineering for improved traits.