MICROPROPAGATION

Vitroplant’s strongest point is the “in vitro” multiplication (or “micropropagation”) that has shown its fundamental importance for the affirmation of modern nursery.
“In vitro” multiplication or “micropropagation” is a vegetative propagation technique, carried out in sterility, which allows plant species to be propagated quickly and in large quantities. With this system rooted plants are obtained, uniform and identical from the morphological point of view. Thanks to this technique it is possible to multiply self-rooted varieties and plants that are difficult to propagate with traditional methods. The “in vitro” technique represents a very powerful means for the nursery activities and for the genetic-sanitary certification because it allows to obtain plant material with unchanged characteristics of health and genetic purity.

The “in vitro” injection is carried out with the collection of shoots from a basic mother plant guaranteed in terms of health and genetic identity. The branch fragments are carefully cleaned with ethyl alcohol, then sterilized with sodium hypochlorite or other chemical sterilizing agents. What follows is the multiplication of the material as reported in the procedures and company protocols.

Scheme of in vitro multiplication: it contemplates the different steps in which the plant, starting from the “in vitro” introduction phase, covers all the stages up to the rooting and acclimatization in the greenhouse.

The advantages of micropropagation are many:

• Conservation of “mothers” plants in isolated greenhouses, where monitoring the genetic health certification;
• Possibility to propagate the plant material regardless of the seasonal trend, but based on market needs;
• Possibility of multiplying species or particular genotypes that are difficult to propagate with traditional techniques (for example species with low rhizogenic potential);
• Ability to supply high productions in limited spaces and in short times;
• Guarantee of genetic uniformity of new plants compared to the mother plant;
• Reproduction of virus-free plants;
• Conservation of the germplasm of a species. Conservation of those genotypes that for various reasons are no longer used, but have very important genetic characters, which instead of being collected in field collections can be in vitro preserved;
• Guarantee of reduced genetic variability.

The first attempt to cultivate plant cells “in vitro” date back to 1902. The German G. Habertland made the first hypotheses of the existence of growth hormones which he called “enzymes”. Later P.R. White 1939, F. Skoog 1944, laid the first bases for the in vitro multiplication of tissues. While Murashige T. formulated the first protocols of tobacco multiplication.In the context of the application of “in vitro” crops, the vegetative “micropropagation” of genotypes selected under sterile conditions has taken an enormous importance. The “in vitro” “micropropagation” or (cloning) has the purpose of obtaining a rapid propagation starting from a portion of a “mother” plant. The advantages are significant in terms of health, quality and uniformity of the material. Important steps for practical and application purposes of this technique, in fruit-growing, have been marked by some publications. We point out the authors in chronological order: Murashige T., Scook F. 1962; Zuccherelli Gilberto, 1979. (Drupacee, Fragola, Actinidia); Rugini E. and Fontanazza G. 1981 (olive tree); Zimmermann RH. 1983, Melo; Standardi A., Catalano F. 1983 Actinidia. This technique has strongly entered the field of plant multiplication and it has greatly improved the nursery production of almost all fruit species, as for horticultural, floricultural and forestry ones. It is a powerful means to produce self-rooted varieties and rootstocks restored from viruses, bacteria, fungi and mycoplasmas.