DIFFERENCES IN LEAD TOLERANCE BETWEEN ALLIUM-CEPA PLANTS DEVELOPING FROM SEEDS AND BULBS

Tolerance to lead of three of Allium cepa L. varieties grown from seed s and bulbs was compared. In all cases plants developing from bulbs we re found more tolerant to lead than those developing from seeds. Durin g 10 days of exposure to lead, the difference in the tolerance index b etween adventitious and seedling roots was 24% on average (7-61% depen ding on the plant variety and the dose of lead), which was significant . In all cases, the seedlings contained more lead in their tissues tha n the plants that had developed from bulbs. This observation may expla in a difference in lead tolerance between these developmental phases o f Allium cepa.