Salt response of seeds and pollen of pistacia species

Abstract

The salt response of five Pistacia species at the germination stage has been investigated and we have evaluated if the germination capability of seeds and pollen under salt stress parallel to each other. Seeds of P. atlantica, P. terebinthus, P, palaestina, P. vera and inter P. atlantica et P. terebinthus were germinated in six saline solutions with electrical conductivities (EC) ranging from 7 to 42 dS/m. Similarly, pollen was germinated in vitro in twelve saline solutions with ECs ranging from 0.5 to 11.5 dS/m. The EC50, EC at which germination capacity was 50% of the control, was used as the salinity-tolerance parameter. Germination decreased with increasing salinities in the five species. The ranking in salinity tolerance for seed germination, as given by the EC50 (dS/m) in parenthesis, decreased in the order: P. atlantica (26.9) > inter P. atlantica et P. terebinthus (23.2) > P. terebinthus (22.5) > P. palaestina (19.8) > P. vera (18.4). Decreases of pollen germination with increasing salinities were much larger, indicating that the pollen is much more sensitive to salinity. The corresponding ranking for pollen germination was: P: terebinthus (7.3) > inter P. atlantica et P. terebinthus (7.0) > P. atlantica (6.2) > P. vera (3.1) > P. palaestina (2.9). The results suggest a certain parallelism between the salinity tolerance at the gametophytic (pollen) and sporophytic (seed) phases. If this conclusion is substantiated with a larger number of Pistacia species, it will offer a potential for selection at the gametophytic phase and therefore, for facilitating and speeding up the screening for salt tolerance.