Closing Remarks for the Workshop on Tissue Culture and Transformation S7

1
Closing Remarks for the Workshop on Tissue
Culture and Transformation (S7)

• Participants N.Tylor, K. Reamakers, T.
  Zimmerman, P. Chavarriaga, P. Zhang, AM Thro, S.
  Zok, K.E. Kpemoua, E. Hopps and R. Escobar

2
Progress made since CBN-IV

• Transgenic plants with specific traits were
  discussed in starch and biotic stress sessions of
  CBN-V.
• 15 genes (traits) used for transformation, 10
  were new. Five marker genes still in use. At
  least 8 different promoters of either
  constitutive, inducible or specific expression
  were reported. For CBN-IV, only two promoters
  were in use.
• Development of TC systems for transformation 4
  labs working with FEC, 1 lab with direct
  embryogenesis, 1 lab with organogenesis.
• FEC developed for 20 new cultivars, 12 of which
  are farmer accepted.
• Organogenesis from SE cotyledons has been induced
  in 15 African cultivars. 10 have been moved to
  the fields.
• RITA is currently used to improve transgenic
  plant recovery and for efficient propagation of
  transgenic and non-trangenic plants
• 208 cultivars (42 of the core collection), 4
  wild species and FEC from two cultivars have been
  cryopreserved and successfully recovered

3
TC Bottlenecks

• No information is available on farmers
  acceptance of transgenic cassava.
• FEC development is time-consuming.
• Difficulty to regenerate FEC for all cultivars.
• Regeneration efficiency is low.
• Somaclonal variation from FEC-regenerated plants.
• Organogenesis is time consuming.

4
Field Testing

• At least four labs ready to move transgenics to
  the fields with modified starch, virus, herbicide
  and insect resistance genes, and acyanogenesis.
• Three possible places with Biosafety regulations
  in place Virgin Islands (USA), CIAT (Colombia)
  and Kenia.

5
Technology Transfer

• No labs from developing countries asking for
  transformation technology yet. Probably the
  technology is not robust yet to be transferred
  (?)
• Low cost propagation technology is available to
  NPs and other users in developing countries.

6
Conclusions

• We believe we have made significant progress in
  TC and transformation in the last two years.
  However, there are still bottlenecks that need to
  be overcome to achieve more efficient systems,
  especially in transformation. For this purpose it
  would be desirable to improve communication and
  collaboration among different labs to share the
  know-how of basic technologies for the benefit
  of all.