求翻译：在实验室水培条件下，研究了不同浓度的Pb2+对黄豆、绿豆的生长状况、发芽率和根长、芽长的毒害影响。观察发现：随着Pb2+浓度的增加，根长、芽长抑制率逐渐增大。测量结果表明，随着重金属离子浓度的增加黄豆与绿豆都呈现根长、芽长逐渐变短的趋势，发芽率变化较小，不太明显。是什么意思？

Under water culture conditions in the laboratory, research the different concentration of Pb2+ on the growth status of bean, mung bean and long germination and root, Bud long, toxic effect of. Observed: with the increase in concentration of Pb2+, root length, Bud long suppression rate increases. Measurement results show that, as the heavy metal concentrations increase long beans and mung beans are rendered and Bud long trend for grow shorter, less germination percentage change, less obvious.