Étude de la germination des graines du Pistacia atlantica Desf. (Pistachier de l'Atlas)

Abstract

Our study is wanted to match the requirements of the seed of the pistachio tree of the Atlas (Pistacia atlantica Desf.) to obtain an optimal germination of a region in the South of Algeria (Djelfa). It appears through this study that, in order to obtain a capacity of an optimal germination, the seeds of the Atlas’ pistachio tree should be freshly harvested, be scarified (eliminate the soft exocarp), soaked during 192H (the water being changed every 24h), allowed to germinate in a humid stratification (sand) and at 25°C. However, the other factors must be taken into account ; the diameter, the cycle’s duration of the illumination by the white light, and the origin of the seed. The estimate of the criteria of quality concerning the fresh seeds shows that they are of satisfactory quality. However, the water content of the seeds is low in below the same limits for the orthodox seeds. The conservation in cold (5°C) causes the emergence of a germination’s inhibition of integumentary origin caused by the fat oils, essential ones, and the tannins contained in the seeds. These substances are known for their inhibitory effect of germination under very specific thermal conditions. Nevertheless, it is possible to apply some treatments likely to lift this inhibition (total or partial scarification, cold stratification, gibberellic acid, sulfuric acid and leaching). The test of germination of the pistachio tree of the Atlas is realized in the nursery by applying different treatments ; scarification by the sulfuric acid, stratification at 4°C and soaking in the gibberellic acid GA3. The results obtained from the germination tests assure that the treatments applied have increased the germinability of the seeds.