ctc

• Micropropagation involves several stages: Motherplant selection and preparation, Establishment of axenic/aseptic cultures, Shoot multiplication, Root formation, Acclimatization/Hardening & Transfer to Field.
• In the first stage of micropropagation, Motherplant selection and preparation, healthy and disease-free stock plants are chosen and the explants, such as shoot tips, are collected from these plants.
• Pre-treatment of explants in the first stage of micropropagation involves physical and chemical treatments of stock plants.
• The second stage of micropropagation, Establishment of axenic/aseptic cultures, involves placing tissue into culture and having it initiate microshoots, which are shoots developed during tissue culture.
• This stage of micropropagation can be difficult due to contamination and production of phenolic compounds by the explant.
• The goal in the first stage of micropropagation is to optimize a surface disinfestation protocol and nutrient medium for survival and growth of the explant.
• In the second stage of micropropagation, Shoot multiplication, a cytokinin enhances multiple-shoot production from the pre-existing axillary buds or multiplication is achieved by adventitious bud formation from leaf, stem, or petiole explants.
• The elongated shoots are cut from the original culture and are subcultured as nodal explants.
• These nodal explants may have the leaves removed and are typically 2 to 4 nodes in length.
• These shoots can be inserted into the medium in a vertical position or laid horizontally on the surface.
• Avoid pushing shoots too deeply into the agar and submerging the nodes.
• In the third stage of micropropagation, Root formation, roots are initiated on microcuttings, which are single microshoots moved to an agar medium to induce rooting either in vitro or ex vitro.
• The rooting medium commonly used in micropropagation is IBA, IAA, and NAA.
• Many laboratories now remove unrooted shoots from the in vitro environment and root them outside the culture vessel in the fourth stage of micropropagation, Acclimatization/Hardening & Transfer to Field.
• In the fourth stage of micropropagation, plants are gradually moved to open-air conditions, where they are exposed to a lower relative humidity and higher light intensities.
• Stomatamorphology of tissue culture grown plants in many cases reveals that prior to hardening, they do not function normally, either remaining open or closing too slowly.
• Plants must be protected until stomata respond more quickly in the fourth stage of micropropagation.