Optimization of Sterilization Method, Callus and Shoot Induction of Catharanthusroseus explants

Abstract

Catharanthusroseus, the Madagascar
periwinkle belongs to the family Apocynaceae.
Vincristine and vinblastine alkaloids are the common
anticancer compounds found in this plant. Sterilization
procedures were optimized to eliminate contaminations.
Two parameters; concentration of Chlorox® solutions
(v/v) and incubation time (min) were optimized. Five
concentrations of Chlorox® solutions were tested for
leaf and petiole explants (5%, 8%, 10%, 12%, and
15%) and three concentrations for stem explants (10%,
15%, and 30%). The explants treated with different
concentrations of Chlorox® solutions were then
subjected to three incubation time; 15, 30, and 45 min.
The optimal concentration of Chlorox® solution for
stem explants was 30% (30 min) while for petiole and
leaf explants, the optimal concentration was 12% (15
min). Young leaves, stems, and petioles from mature
plant of C. roseus were placed on MS-based medium
supplemented with NAA (0.75-1.25mg/l) and BA (0.25-
0.30mg/l) to determine the type of explants and the
optimum concentration of plant growth regulators for
callus induction and shoot organogenesis. After 2 weeks
of culture, all of the explants formed green and offwhite
callus at the cut end of the explants. The highest
frequency of callus formation was obtained from leaf
explants 1.3g ± 0.4 (100%) at a combination of 0.2mg/l
BA with 1.25mg/l NAA. Shoots were regenerated from
petiole explants supplemented with 0.2mg/l BA with
0.75mg/l NAA at week 8. As for leaves and stems
explants did not induce shoot formation in medium
containing BA and NAA. Highest number of root per
explants 0.8 ± 0.3 were regenerated from leaves explants
the MS medium supplemented with 0.3mg/L BA and
1.0mg/L NAA. From the results, the best explants for
callusing and shoot induction are petiole of C. roseus.