Abstract
Seed populations from a majority of species and cultivars of Allium yield up to 15% germination under atmospheres containing NH3 together with equal volumes of N2 o air. Selected onion and leek cultivars tested in a range of NH3 or O2 compositions show little or no dependency upon quantitative variations in these gases. Radicles from seeds germinated in ammonia displayed low frequencies of abnormal mitotic activity. Comparisons of NH4 OH with other bases, and with salts indicated that seed behavior could not be accounted for solely by osmolar or alkaline factors. Aspects of NH3 toxicity, tolerance and permeation were also considered.