| Under conditions of growth chamber,hydroponic culture was employed to investigate the effects of different boron concentration on the morphology and growth of mung bean(Phaseolus aureus Roxb.).The results showed that limited supply of boron reduced mung bean biomass production,which was accompanied with an increased shoot to root ratio.Leaf expansion also was inhibited together with specific leaf area(SLA) by boron deficiency.The boron deficiency plant appears inter-venial chlorosis,thickening,crisping leaves and increased leaf weight ratio(LWR).Compared with optimum boron supply concentration,too high boron supply levels badly influenced plant growth,however did not induce significant changes in shoot to root ratio,which suggest that supra-optimum boron supply has similar influence on above-ground and blow-ground growth.Born toxicity led to early abscission of the older leaves,reducing total photosynthesis leaf area,but did not influence SLA or LWR. |