tissue culture
Once many new shoots have formed , these are transferred to a new flask with a fresh culture medium that does not contain shoot promoting growth regulators . ( Instead , this second medium often contain auxins , which allow the shoots to elongate further and roots to rapidly form .) The mass of shoots can be extracted from the jar using sterilised forceps and a sharp knife . They can then be divided or pulled apart into many individual plantlets . These divisions are then transferred into the new culture medium to develop for a few weeks under lights . This process is similar for many plants that are propagated from leaves . Once the young plantlets inside the flasks are sufficiently developed , they are taken from the culture flask and carefully hardened off . ( The plantlets inside the jars or flasks have been protected with warmth and high humidity , so they are initially very tender .) This process applies both to growers who have purchased flasks of plantlets from a tissue culture lab and those who have carried out their own micropropagation . The hardening off process is carried out using hydroponic methods ; that is , using sterile soilless media under low-level natural or artificial fluorescent lighting in a protected environment . The plantlets are removed from the culture jar or flask , and any excess agar medium is washed away . The young plant can then be potted into small containers or trays of sterile media . Finegrade perlite or perlite / vermiculite mixtures work well for this process , as does stone wool and similar hydroponic media . The plantlets of most species can then be placed in a high-humidity tent , in a plastic bag for small pots , or under intermittent misting to retain humidity as the plant adjusts to normal growing conditions . Initially , only distilled or RO water should be given for the first few days , then a dilute quarter-strength seedling nutrient can be applied . Young plants typically require four to six weeks to harden off sufficiently . As they grow , light levels are increased , the humidity can be gradually lowered , and the nutrient can gradually increase in strength .
Top : Plantlets contained in tissue culture vessels . Bottom : Plantlets being removed from the tissue culture growth medium to a potting medium .
“ USING BASIC tissue culture methods , even a small grower can rapidly produce high numbers of clones from a single plant .”
Materials and Supplies
For those new to tissue culture , a basic starter kit can be purchased from some suppliers and , increasingly , from hydroponic retailers . Kits are a good way to initially develop culturing skills , as all the hard work of sourcing agar medium ingredients , suitable jars or flasks , and other equipment has already been done . For those who are a little more DIY , many online retailers selling home tissue culture supplies can provide specific tissue culture agar mediums for different plants species and procedures , such as shoot multiplication , root development , and growing on plantlets . This removes the complicated step of formulating an agar medium for home propagation .
Tissue culture methods may seem a little complex and challenging at first , but once the basics of preparing plant material and a good understanding of aseptic methods have been developed , the process can be highly rewarding . Not only can favourite or carefully selected plants be cloned rapidly in high numbers , but more advanced methods can germinate difficult seeds or spores , produce virus-free planting stock , and play a vital role in ongoing plant breeding and improvement programs . Small-scale tissue culture is also well-suited to an indoor garden environment where artificial lighting and carefully controlled conditions can be provided to grow new plantlets from tiny pieces of excised tissue .
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