Study of Seed Dormancy Origins in Three Atlas Pistachio Ecotypes (Pistacia Atlantica Desf.)

Abstract

The Atlas pistachio (Pistacia atlantica Desf.), a rustic tree distributed in different bioclimatic areas, is rapidly declining, particularly in Algeria. Among the actions to be undertaken is the launch of a restocking program. Nevertheless, Atlas pistachio seed dormancy is an obstacle limiting its germination and obtaining seedlings. The aims of the present study are to define the nature of seed germination inhibitors and to propose pretreatments that would limit their effects. Seeds were collected from three locations in Algeria. Quantitative and qualitative traits of phenolic compounds and total antioxidant activity were determined at three levels, namely, seed, epicarp and kernel. Germination was investigated in seeds with epicarp, epicarp removed, and with or without H2O2 treatment. Results showed that whole seed germination is not effective. Scarification by removing epicarp did not improve the germination rate. Chemical analyses indicated that seeds, kernel and epicarp were rich in total phenolic compounds. These compounds are known to limit seed germination in several species. Application of hydrogen peroxide induced a significant increase in seed germination rate in the three ecotypes. H2O2 caused inhibition of polyphenol compounds effects on germination. The results indicated that the inhibitory effect of phenolic compounds can be found at the kernel level instead of the epicarp. However, studied genotypes indicated that only one ecotype was distinguished by seed dormancy that originated in the epicarp and kernel.

Evidence of Alectoris chukar (Aves, Galliformes) as seed dispersal and germinating agent for Pistacia khinjuk in Balochistan, Pakistan

“…1 -Cumulative viability and germination rate of pistachio seeds from chukar fecal drops and control (direct sowing) during the experiment. iForest -Biogeosciences and Forestry germination rate of the species (Labdelli et al 2019). It may be hypothesized that the faster germination of seeds from fecal drops could be due to the role played by the enzymes of the partridge digestive tract that break the sclerotic endocarp of seed cover.…”

Nutritional Content and Antioxidant Capacity of the Seed and the Epicarp in Different Ecotypes of Pistacia atlantica Desf. Subsp. atlantica

“…is rich in vitamin C as a natural antioxidant. This richness in antioxidants results in the maintain of seed dormancy by limiting water and oxygen diffusion to almond [ 50 ].…”

“…Total phenols consisted of phenolic acids, vanillin and flavonoids, and their level depends on growth stage and on species (or subspecies) [ 47 , 48 , 49 , 50 , 51 , 52 ]. These compounds can delay or inhibit the oxidation of lipids by impeding the initiation or propagation of oxidative chain reactions [ 53 ].…”

“…Methanol was found as the most efficient solvent for phenolic extraction according to previous works [ 6 , 23 , 50 ]. One gram of seed and epicarp were crushed separately into powder using a mortar grinder (RM 200-Retsch, Haan, Germany) with 20 mL of methanol and stirred for 48 h in dark at room temperature.…”

“…The mixture was filtered through a hydrophilic polypropylene (GHP) filter with 0.45 µm pores; the solvent was eliminated under reduced pressure in a rotary evaporator at 60 °C. The residue (crude extract) was dissolved in 3 mL of methanol for analysis [ 23 , 25 , 50 ].…”