Effects of Low Phosphorus on Taproot Elongation of Soybean [Glycine max (L.) Merr.]

The study elucidated the effect of phosphorus (P) on soybean taproot elongation by the methods of rolled paper culture and stratified agar culture. Our results showed that the taproot elongation of soybean,especially the distance from the taproot tip to newest lateral root,was stimulated by low phosphorus. The taproot elongation promoted by low phosphorus mainly attributed to the delay of the differentiation in the elongation zone of soybean root and could not be affccted by applying phosphite. Under the condition of heterogeneous distribution of phosphorus in stratified agar culture,low phosphorus accelerated taproot elonga-tion with no phosphorus in the top or bottom agar.