A preliminary study on resin duct initiation and development in one-year-old seedlings of Pistacia atlantica subsp. mutica

Natural gum and resins are basic materials required by different industries, including food, pharmaceutical, cosmetic, painting, etc.  They are extracted from various plants such as coniferous, citrus, elm, oleaster, apricot and wild pistachio species.  The main problem is that the gum should be extracted from mature and aged trees. Cutting the trees bark and some times the young wooden layer of the stem or young branches, is one of the methods of extracting gum and resin in these trees.  Insects bit and bark damage by some fungi also is a way to extract gums, because the trees produce gum or resin against disease contamination.  In that case, the plants are very aged and weak.  Thus, gum and resin exudation, particularly when is repetitive, can lead to general plant weakness and finally to its death..It was tried to obtain extract from young seedlings of Pistacia atlantica in this research program which require a preliminary study of resin and gum ducts physical structure and their growth and development process.  Resin ducts were studied in root, shoot and leaf by picking one-year organ samplings.  Samples were fixed with FAA fluid and kept in fridge (4- 8 °C) for a while.  Then the samples were hydrated with an alcohol series and cut using Rm-2035 microtome.  five to 10 thick sections were stained with periodic acid and Schiff’s reagent (PAS) and toluidine blue O.  Preparations were studied under a light microscope and photographs were taken using 100 ISO Konica Minolta color film.As a result, the number of gum duct in the bark of root, stem and leaf was discriminated in Pistacia atlantica seedlings.  The results showed that it is possible to identify different genotypes of Pistacia atlantica through this differentiation.  Moreover, it might be demonstrated that despite of former idea for resin production of seedlings, it is possible to have resin product at seedling stage.