Abstract:
This study was carried out to determine the effects of different dormancy-breaking treatments including stratification, sulphuric acid
scarification, dehulling (removing the mesocarp and exocarp from
the nut) and gibberellic acid (GA3) on seed germination and seedling
development of two different Pistacia khinjuk genotypes (A and B)
using as rootstock for pistachio cultivars. Seed dormancy-breaking
treatments were shelled (control), shelled + GA3, dehulled, dehulled
+ GA3, sulphuric acid scarification and sulphuric acid scarification
+ GA3 applications in the present experiment. The seeds of both
genotypes were stratified at 4 ºC for 50 days after the dormancybreaking treatments. Stratified seeds were sown in the vials filled
with peat in the greenhouse to determine the germination percentage. Plantlets were transplanted to plastic containers to determine
the vegetative growth. The highest germination rate was obtained
from sulphuric acid scarification in both P. khinjuk genotypes. In
P. khinjuk-A seedlings, the highest stem growth was obtained from
scarification and dehulled applications, whereas the poorest development was observed from dehulled + GA3 application. The best
growth in the P. khinjuk-B seedlings was obtained from scarification
+ GA3 application. The effect of the dehulled application on the root
development of P. khinjuk-A seedlings was better than the other applications; however the effect of dormancy-breaking applications on
root development of P. khinjuk-B seedlings was found to unsteady.
Scarification increased the number of leaves in both genotypes. As
a result, dormancy-breaking applications have been found to be effective on seed germination and seedling growth of P. khinjuk. It
was determined that GA3 applications negatively affected both seed
germination and root, stem and leaf growth of P. khinjuk-A.
