PLANT REGENERATION FROM MATURE SEED'S EMBRYO OF PINUS MERKUSII JUNGH. JUNGH VRIES

Abstract

Dendrolimus punctatus  (Walker)  is  endemic  to  Southeast  Asia  and has been the most  serious  damaging insect  on  Pinus merkusii Jungh.  &  de  Vries  species  of  Vietaam  in  recent  years.  In  an  attempt  to  develop ttansgenic Pinus merkusii Jungh. & de Vries plant with  insect resistant  gene, a protocol  for plant  generation from  embryos  of  the  plant  was  carried  out.  The  multi-shoot  induction  protocol  includes  several  steps: The mature seed, at first, was suface-sterilized  in 70% ethanol (v/v), followed by 60% Javen (v/v) and few washes with  sterile  distilled  water.  The  embryos  were  aseptically  removed  from  sterilized  mature  seeds  and  placed horizontally  on the  shoot  induction medium  (WP medium  supplemented  with  1 mgi'  BAP, 2 mgi"' NAA, 1

mgf'  casein  hydrolysate).  After  6 days,  explants  were ttansferred to the  muhi-shoot  medium  (WP medium supplemented  with  9  mgi"'  BAP). Multi-shoots  were ttansferred into  shoot-elongation  medium  consisted  of WP medium supplemented with 0.5 mg f' NAA, 0.2 mg 1"' GA3, 1  mg 1"' activated charcoal. For rooting,  2 - 3 cm long shoots were cultivated on the root induction medium containing 0.5 mgi"' IBA. The highest  frequency of plant regeneration was up to 67.5%. The average efficiency  for regeneration was 12.5 regenerated shoots per embryo.  The  frequency  of  rooted  plant  was  68.9%.  Rooted  plants  successfully  ttansferred  into  the  soil  in greenhouse.