Alleviation of innate and salinity-induced dormancy in Atriplex griffithii Moq. var. stocksii Boiss.

Abstract

Atriplex griffithii var. stocksii is a perennial salt-secreting halophyte that grows in the coastal and inland salt deserts of Karachi, Pakistan. Seeds are surrounded by bracts at maturity, and were inhibited from germinating. when they were enclosed by bracts or when naked seeds were germinated in the presence of their excised bracts but had 60% germination in the absence of bracls. The effect of dormancy relieving compounds (ethephon, fusicoccin, nitrate, thiourea, proline and betaine) in alleviating the effects of innate or salt-induced dormancy on seed germination of A, griffithii was mvestigated. Ethephon and fusicoccin failed to stimulate germination, whereas proline, betaine, nitrogen, and throurea partially alleviated the innate dormancy in seeds. Salinity-induced dormancy was partially alleviated by fusicoccin, proline, betaine, thiourea, and nirrate. The rate of germination in non-saline controls increased significantly when seeds were treated with proline, betaine, and thiourea. Proline, betaine, thioucea, and nitrate also were found to inerease the rate of germination under saline conditions.