Effects of Pb Stress on Seed Germination and Seedlings Growth of Pogonatherum crinitum as Pb Accumulator Plant

In order to understand the effects of Pb stress on the seed germination and seedlings growth of Pogonatherum crinitum which was identified as Pbhyperaccumulator plant, seed germination, germination potential, root length, bud length and embryo weight were measured with different treatments including seven Pb concentrations (0, 50, 150, 300, 600, 800 and 1000mg /L), by taking Paspalum notatum from Gramineae family as control, and to compare the difference of the two plant species in the seed germination indexes, inhibit index and seedling growth indexes under Pb stress. It was showed that lower Pb concentration (50mg/L) stress had positive effect on seed germination potential, germination rate, germination index and vigor index of Pogonatherum crinitum. With the increase of Pb concentration, the inhibition effect on seed germination indexes also gradually increased. The seed germination of Pogonatherum crinitum was significantly inhibited when Pb concentration was over 300mg/L. The study showed that Pogonatherum crinitum had higher endurance to Pb stress though its germination indexes were always lower than those of Paspalum notatum under lower Pb stress, because it still had some germination capacity when Pb stress concentration reached 800mg/L. However there was no obvious effect of Pb stress on the growth of root length and bud length of Pogonatherum crinitum seedlings.