EFFECT OF GROWTH REGULATORS ON THE <i>IN VITRO</i> GERMINATION AND TUBE GROWTH OF MAIZE <i>(ZEA MA YS</i> L.) POLLEN FROM PLANTS RAISED UNDER SODIUM CHLORIDE SALINITY

Abstract

S ummary Pollen grains, collected from maize plants raised under conditions of 0, 80, 120 and 160 meq l −1 salinity, were used to investigate the effect of various growth regulators on in vitro germination and tube growth. Indole‐3‐acetic acid had no effect on germination, irrespective of the source of pollen, whether derived from plants grown under saline or non saline conditions. However, its lower concentrations enhanced tube growth in pollen from salinized plants. Gibberellic acid at a concentration of 1 mg l −1 antagonized the depressive effects of 120 meq l −1 salinity on pollen germination. It stimulated tube growth of pollen from saline, as well as, non‐saline plants. However, pollen from salinized plants required a higher concentration of gibberellic acid. Benzylaminopurine ameliorated inhibitory effects of NaCl salinity both on germination and tube growth of pollen. Abscisic acid inhibited germination to a greater extent in pollen from nonsaline than saline plants; but stimulated tube growth in all cases. The present investigation suggests that pollen from salinized plants responds more to growth regulators than those from non‐salimzed plants.